While surfing around the Internet recently I encountered the 's-plane to z-plane mapping' diagram shown in Figure 1. At first I thought the diagram was neat because it's a good example of the old English idiom:

The seca 869 remote display scale has a 550 lb (250 kg) capacity. The weighing platform connects to a monitor that can be tilted for optimal viewing. The monitor connects to the scale base by a 6.5-foot cable that can be mounted on a table or a wall. #WeighAndMeasure #Measuring https://weighandmeasure.com/product/seca-869-remote-display-flat-scale/

Sea of Stars, Billions and Billions of Stars! The DSLR pointed at part of the constellation Scorpius and Lupus from a dark Desert sky in the Southern Hemisphere. "Cosmic Latte", the color of the Universe. I enjoy shooting wider DSLR Lens views when I am capturing closer detail with my Telescope. Even though a 105mm Lens only shows a fraction of the observable night sky, the "Cosmic Latte" theory does seem to start becoming apparent the wider you go. Research shows that the average colour of the Universe is Beige, and this is referred to as Cosmic Latte. More about Cosmic Latte: en.wikipedia.org/wiki/Cosmic_latte “The size and age of the Cosmos are beyond ordinary human understanding. Lost somewhere between immensity and eternity is our tiny planetary home." - Carl Sagan. Details: 7 x 3 min exposures at ISO 1600. Lens Stopped Down to f/4. Gear: Nikon D750. AF-S VR Micro-Nikkor 105mm f/2.8G IF-ED. Hahnel Giga T Pro II 2.4GHz Wireless Remote for Nikon. Celestron AVX Mount. Astrometry Info: Center RA, Dec: 249.940, -42.519 Center RA, hms: 16h 39m 45.500s Center Dec, dms: -42° 31' 08.484" Size: 19.7 x 13.2 deg Radius: 11.842 deg Pixel scale: 44.3 arcsec/pixel Orientation: Up is 175 degrees E of N View an Annotated Sky Chart for this image. View this image in the WorldWideTelescope. Martin - [Home Page] [Photography Showcase] [eBook] [Twitter] [Facebook] [3D VFX & Mocap] [Science & Physics Page]

Folds Geometry It is fascinating to watch folds form and develop in the laboratory, and we can learn much about folds and folding by performing controlled physical experiments and numerical simulations. However, modelling must always be rooted in observations of naturally folded rocks, so geometric analysis of folds formed in different settings and rock types is fundamental. Geometric analysis is important not only in order to understand how various types of folds form, but also when considering such things as hydrocarbon traps and folded ores in the subsurface. There is a wealth of descriptive expressions in use, because folds come in all shapes and sizes. Hence we will start this chapter by going through the basic jargon related to folds and fold geometry. Shape and orientation  Folds are best studied in sections perpendicular to the folded layering, or perpendicular to what is defined as the axial surface. In general, folds are made up of a hinge that connects two usually differently oriented limbs. The hinge may be sharp and abrupt, but more commonly the curvature of the hinge is gradual, and a hinge zone is defined. A spectrum of hinge shapes exists, from the pointed hinges of kink bands and chevron folds (sharp and angular folds) to the well-rounded hinges of concentric folds. Classification of folds relative to hinge curvature is referred to as bluntness. The shape of folds can also be compared to mathematical functions, in which case we can apply terms such as amplitude and wavelength. Folds do not necessarily show the regularity of mathematical functions as we know them from classes of elementary algebra. Nevertheless, simple harmonic analysis (Fourier transformation) has been applied in the description of fold shape, where a mathematical function is fitted to a given folded surface. In multi-layered rocks, folds may be repeated with similar shape in the direction of the axial trace. Such folds are called harmonic. If the folds differ in wavelength and shape along the axial trace or die out in this direction they are said to be disharmonic. The point of maximum curvature of a folded layer is located in the centre of the hinge zone and is called the hinge point. Hinge points are connected in three dimensions by a hinge line. The hinge line is commonly found to be curved, but where it appears as a straight line it is called the fold axis.  This takes us to an important element of fold geometry called cylindricity. Folds with straight hinge lines are cylindrical. A cylindrical fold can be viewed as a partly unwrapped cylinder where the axis of the cylinder defines the fold axis. At some scale all folds are non-cylindrical, since they have to start and end somewhere, or transfer strain to neighbouring folds, but the degree of cylindricity varies from fold to fold. Hence, a portion of a fold may appear cylindrical as observed at outcrop, even though some curvature of the axis must exist on a larger scale. Cylindricity has important implications that can be taken advantage of. The most important one is that the poles to a cylindrically folded layer define a great circle, and the pole (p-axis) to that great circle defines the fold axis. When great circles are plotted instead of poles, the great circles to a cylindrically folded layer will cross at a common point representing the fold axis, in this case referred to as the b-axis. This method can be very useful when mapping folded layers in the field, but it also works for other cylindrical structures, such as corrugated fault surfaces. Another convenient property of cylindrical folds is that they can be projected linearly, for example from the surface to a profile. Cylindricity is therefore commonly assumed when projecting mapped structures in an area onto cross-sections, particularly in the early 1900 mapping of the Alps by Swiss geologists such as Emile Argand and Albert Heim. Since the validity of such projections relies on the actual cylindricity of the projected structures, the uncertainty increases with projection distance.  The axial surface, or axial plane when approximately planar, connects the hinge lines of two or more folded surfaces. The axial trace of a fold is the line of intersection of the axial surface with the surface of observation, typically the surface of an outcrop or a geologic section. The axial trace connects hinge points on this surface. Note that the axial surface does not necessarily bisect the limbs. It is also possible to have two sets of axial surfaces developed, which is the case with so-called box folds, which are also called conjugate folds from the characteristic conjugate sets of axial surfaces. In other cases, folds show axial surfaces with variable orientations, and such folds are called polyclinal. The orientation of a fold is described by the orientation of its axial surface and hinge line. These two parameters can be plotted against each other, and names have been assigned to different fold orientations. Commonly used terms are upright folds (vertical axial plane and horizontal hinge line) and recumbent folds (horizontal axial plane and hinge line).  An antiform is a structure where the limbs dip down and away from the hinge zone, whereas a synform is the opposite, trough-like shape. Where a stratigraphy is given, an antiform is called an anticline where the rock layers get younger away from the axial surface of the fold. Similarly, a syncline is a trough-shaped fold where layers get younger toward the axial surface. We can even have recumbent synclines and anticlines, because their definitions are related to stratigraphy and youngish direction. However, the terms recumbent and vertical antiforms and synforms have no meaning.  Imagine a tight to isoclinal recumbent fold being refolded during a later tectonic phase. We now have a set of secondary synforms and antiforms. The younging direction across their respective axial surfaces will depend on whether we are on the inverted or upright limb of the recumbent fold. We now need two new terms, synformal anticline and antiformal syncline, to separate the two cases. A synformal anticline is an anticline because the strata get younger away from its axial surface. At the same time, it has the shape of a synform, i.e. it is synformal. Similarly, an antiformal syncline is a syncline because of the stratigraphic younging direction, but it has the shape of an antiform. Technically, a synformal anticline is the same as an anticline turned upside down, and an antiformal syncline looks like an inverted syncline.  Remember that these terms only apply when mapping in polyfolded stratigraphic layers, typically in orogenic belts. As already stated, most folds are non-cylindrical to some extent. A non-cylindrical upright antiform is sometimes said to be doubly plunging. Large doubly plunging antiforms can form attractive traps of oil and gas - in fact they form some of the world’s largest hydrocarbon traps. When the non-cylindricity is pronounced, the antiform turns into a dome, which is similar to a cereal bowl turned upside-down. Domes are classic hydrocarbon traps, for example above salt structures, and geoscientists commonly talk about such traps as having a four-way dip closure. Correspondingly, a strongly non-cylindrical synform is in fold terminology called a basin (the cereal bowl right-way up). A monoclinal fold is a sub-cylindrical fold with only one inclined limb. Monoclinal folds (or just monoclines for short) are commonly found as map-scale structures related to reactivation of, or differential compaction across, underlying faults or salt structures. In addition to orientation and stratigraphic relations, folds are commonly described or classified according to tightness. Tightness is characterized by the opening or interlimb angle, which is the angle enclosed by its two limbs. Based on this angle, folds are separated into gentle, open, tight and isoclinal. Tightness generally reflects the amount of strain involved during the folding. Folds usually come in groups or systems, and although folds may be quite non-systematic, neighboring folds tend to show a common style, especially where they occur in rows or trains. In these cases they can, akin to mathematical functions, be described in terms of wavelength, amplitude, inflection point and a reference surface called the enveloping surface. The enveloping surface is the surface tangent to individual hinges along a folded layer. Dip isogons  Some folds have layers that maintain their thickness through the fold, while others show thickened limbs or hinges. By orienting the fold so that its axial trace becomes vertical, lines or dip isogons can be drawn between points of equal dip on the outer and inner boundaries of a folded layer. Dip isogons portray the difference between the two boundaries and thus the changes in layer thickness. Based on dip isogons, folds can be classified into the three main types:  Class 1: Dip isogons converge toward the inner arc, which is tighter than the outer arc.  Class 2 (similar folds, also called shear folds): Dip isogons parallel the axial trace. The shapes of the inner and outer arcs are identical.  Class 3: Dip isogons diverge toward the inner arc, which is more open than the outer arc.  Class 1 folds are further subdivided into classes 1A, 1B and 1C. 1A folds are characterized by thinned hinge zones, while 1B folds, also called parallel folds and, if circle shaped, concentric folds, have constant layer thickness. Class 1C folds have slightly thinned limbs. Class 2 and, particularly, Class 3 folds have even thinner limbs and more thickened hinges. Among these classes, Class 1B (parallel) and 2 (similar) geometries stand out because they are easy to construct and easy to identify in the field. One way of plotting folds according to the dip isogon classification, where folds are considered as upright structures (vertical axial planes), so that the dip of the limb (a) increases in each direction from 0 at the hinge point. This is the thickness measured orthogonal to the layer at one of the two corresponding points of equal dip on each arc. Symmetry and order  Folds can be symmetric or asymmetric in cross-section. A fold is perfectly symmetric if, when looking at a cross section perpendicular to the axial surface, the two sides of the axial trace are mirror images of one another. This implies that the two limbs are of equal length. The chevron folds and concentric folds are examples of symmetric folds. If we extend this concept to three dimensions, the axial plane becomes a mirror plane, and the most symmetric folds that we can think of have two other mirror planes perpendicular to the axial plane. This is the requirement of orthorhombic symmetry. For symmetric folds the bisecting surface coincides with the axial plane. In fact, this is how we distinguish between kink bands and chevron folds: chevron folds are symmetric while kink bands have one long and one short limb. This leaves us with one symmetry (mirror) plane only, the one perpendicular to the axial surface, and the symmetry is said to be monoclinic.  Symmetric folds are sometimes called M-folds, while asymmetric folds are referred to as S-folds and Z-folds. Distinguishing between S- and Z-folds may be confusing to some of us, but Z-folds have short limbs that appear to have been rotated clockwise with respect to their long limbs. Z-folds thus mimic the letter Z when considering the short limb and its two adjacent long limbs. S-folds imply a counter-clockwise rotation, and resemble the letter S (this has nothing to do with the difference in angularity between S and Z). Interestingly, S-folds become Z-folds when viewed from the opposite direction. Plunging folds are usually evaluated when looking down-plunge, while viewing direction must be specified for folds with horizontal axes.  Fold systems consisting of folds with a consistent asymmetry are said to have a vergence. The vergence can be specified, and the vergence direction is given by the sense of displacement of the upper limb relative to the lower one. We can also relate it to the clockwise rotation of the inclined short limb,where a clockwise rotation implies a right-directed vergence. Fold vergence is important in structural analysis in several ways. Large folds tend to have smaller folds occurring in their limbs and hinge zones. The largest folds are called the first-order folds, while smaller associated folds are second and higher order folds. The latter are also called parasitic folds. First-order folds can be of any size, but where they are map scale we are likely to observe only second- or higher-order folds in outcrops. If a fold system represents parasitic (second order) folds on a first-order synformal or antiformal structure, then their asymmetry or vergence indicates their position on the large-scale structure.This relationship between parasitic and lower order folds can be extremely useful for mapping out fold structures that are too large to be observed in individual outcrops. The vergence of asymmetric fold trains in shear zones is generally unrelated to lower-order folds and can give information about the sense of shear of the zone. Such kinematic analysis requires that the section of observation contains the shear vector and should be used together with independent kinematic indicators. Fold asymmetry may relate to position on a lower-order fold, sense of shear or orientation of the folded layer relative to the strain ellipse. Credits: Haakon Fossen (Structural Geology)

Detail Specification of Highest Performance DSLR Camera Canon EOS 5DsR  The Canon EOS 5DS R includes an all-new 50.6 megapixel CMOS sensor, alongside double DIGIC 6 processors. The 'R' model counterbalances the counter associating channel for greatest goals (to the detriment of moiré). The self-adjust framework has an aggregate of 61 points (in a 'high thickness reticular cluster'), 41 of which are cross-type. It utilizes the equivalent 150,000-pixel RGB+IR metering framework as the EOS 7D II with a scene recognition framework. The metering framework likewise has an enemy of glint work for shooting under sodium vapour lights. The ISO extend on the camera is 100-6400, expandable to 12800.  The 5DS R has a more unbending skeleton than the EOS 5D III so as to limit camera shake and improve flexibility. The shade is appraised to 150,000 cycles. The 5DS game is a 'Wise Viewfinder II' which has an installed straightforward LCD board that can show edited shooting outlines, synthesis networks, and an electronic dimension. It likewise sports a 3.2" LCD show with 1.04M spots and double memory card openings (CompactFlash and SD/SDHC/SDXC with UHS-I support).  Picture takers have a decision of two harvest modes: 1.3x (30.5MP) and 1.6x (19.6MP) just as medium and little size Raws. The 5DS can shoot persistently at 5 fps. Video-wise, the 5DS backings 1080/30p account, however, needs clean HDMI yield and an earphone jack. Short Description about Canon EOS 5DS R Digital SLR Camera w EF 24-70mm F2.8 Lens Bundle Price $5298.00as of May 14, 2019,  Brand Canon Resolution 50.6 Megapixel Sensor Size Full Frame Sensor Type CMOS ISO 100 - 6400 Viewfinder Optical Display Size 3.2 inches Shooting Speed 4.8 fps Video Resolution 1920 x 1080 Focal Length 24 - 70 mm 35mm Equivalent 24 - 70 mm Max Aperture F/2.8 Optical Zoom 2.9x Release Date June 2015 Body Weight 32.8 ounces Lens Weight 28.4 ounces Weight 61.2 ounces Detail Specification of  DSLR Camera Canon EOS 5DsR  Specifications Canon EOS 5Ds R Year Introduced 2015 Megapixels 50.6 Total Pixels 53.0 Sensor Size 36.0 x 24.0mm Pixel Dimensions 8688 x 5792 Pixel Size 4.14µm Diffraction-Limited Aperture f/6.7 Aspect Ratio 3:2 Sensor Cleaning EOS Integrated Cleaning System with fluorine coated Low-Pass Filter Lens Mount EF (excludes EF-S lenses), TS-E, MP-E FOVCF 1.0x Image Processor Dual DIGIC 6 Autofocus Type TTL-CT-SIR with a dedicated CMOS sensor Points 61 Point / 41 f/4 cross-type AF points inc 5 dual cross-type at f/2.8 The number of cross-type AF points will differ depending on the lens. Working Range EV -2 - 18 (at 20°C & ISO100) Modes One-Shot AI Focus AI Servo Point Selection Automatic selection: 61 points AF Manual selection: Single-point AF (61, 41 cross-type only, 15 or 9 points selectable) Manual selection: Spot AF Manual selection: AF point Expansion 4 points (up, down, left, right) Manual selection: AF point Expansion surrounding 8 points Manual selection: Zone AF AF points can be selected separately for vertical and horizontal shooting Predictive Assist Beam Emitted by optional dedicated Speedlite Microadjustment AF Menu +/- 20 steps ( wide and tele setting for Zooms) Adjust all lenses by the same amount Adjust up to 40 lenses individually Adjustments remembered for lens by serial number Exposure Control Metering Modes 150,000-pixel RGB+IR metering sensor EOS iSA System with 252-zone metering: (1) Evaluative metering (linked to All AF points) (2) Partial metering (approx. 6.1% of viewfinder at centre) (3) Spot metering (approx. 1.3% viewfinder at centre) * AF point-linked spot metering not provided (4) Centre-weighted average metering Metering Range EV 1 – 20 (at 23°C with 50mm f/1.4 lens ISO100) Exposure Comp +/-5 EV in 1/3 or 1/2 stop increments (can be combined with AEB). AEB 2, 3, 5 or 7 Shots +/-3 EV 1/3 or 1/2 stop increments ISO Sensitivity Auto (100-6400), 100-6400 (in 1/3-stop or whole stop increments) ISO can be expanded to L: 50, H1: 12800 Shutter Speed 30 - 1/8000 sec (1/2 or 1/3 stop increments) + Bulb (Shutter speed range available varies according to shooting mode) WB Settings AWB (Ambience priority/White priority), Daylight, Shade, Cloudy, Tungsten, White Fluorescent light, Flash, Custom, Color Temperature Setting. White balance compensation: 1. Blue/Amber +/-9 2. Magenta/ Green +/-9. Custom WB Yes, 1 setting can be registered WB Bracketing +/-3 levels in single-level increments 3 bracketed images per shutter release. Selectable Blue/Amber bias or Magenta/ Green bias. Viewfinder Type Pentaprism Coverage Approx. 100% Magnification Approx. 0.71x Eyepoint Approx. 21mm Diopter Correction -3 to +1 m-1 (diopter) Focusing Screen Fixed (Transmissive LCD screen) Mirror Motor-Driven Quick-return half mirror (Transmission: reflection ratio of 40:60, no mirror cut-off with EF600mm f/4 or shorter) Information AF information: Single/Spot AF points, AF Frame, AF status, Focus indicator, AF mode, AF point selection, AF point registration Exposure information: Shutter speed, aperture value, ISO speed (always displayed), AE lock, exposure level/compensation, flash metering, spot metering circle, exposure warning, AEB, metering mode, shooting mode Flash information: Flash ready, high-speed sync, FE lock, flash exposure compensation, red-eye reduction light. Image information: Card information, maximum burst (2 digit display), Highlight tone priority (D+). Composition information: Grid, Electronic level Other information: Battery check, Warning symbol, Flicker Detection, drive mode, white balance, JPEG/RAW indicator DOF Preview Yes, with the Depth of Field preview button. Eyepiece Shutter On strap LCD Type 3.2" (8.11cm) Clear View II TFT, approx. 1040K dots Coverage Approx. 100% Viewing Angle Approx. 170° Coating Anti-reflection and Solid Structure Brightness Adj Adjustable to one of seven levels Display Options (1) Quick Control Screen (2) Camera settings (3) Dual Axis Electronic Level Flash Built-in GN N/A (ISO 100, meters) Built-in Coverage N/A Built-in Recycle Time N/A Modes E-TTL II Auto Flash, Metered Manual X-Sync 1/200sec (EX-series Speedlites only) Exposure Compensation +/- 3EV in 1/2 or 1/3 increments Exposure Bracketing Yes, with compatible External Flash Exposure Lock Yes 2nd Curtain Sync Yes Hot Shoe/PC Terminal Yes / Yes External Flash Comp E-TTL II with EX-series Speedlites, wireless multi-flash support External Flash Control Via camera menu Shooting Shooting Modes Auto+, Program AE, Shutter-priority AE, Aperture-priority AE, Manual (Stills and Movie), Custom (x3) Picture Styles Auto, Standard, Portrait, Landscape, Neutral, Faithful, Monochrome, User Defined (x3) Colour Space sRGB and Adobe RGB Image Processing Highlight Tone Priority Auto Lighting Optimizer (4 settings) Long exposure noise reduction High ISO speed noise reduction (4 settings) Auto-Correction of Lens Peripheral illumination Chromatic aberration correction Distortion correction Resize to M1, M2 or S RAW image processing - during image Playback only Multiple exposures HDR images 5 presets Drive Modes Single, Continuous L, Continuous H, Self-timer (2s+remote, 10s+remote), Silent single shooting, Silent continuous shooting Continuous Shooting Max. Approx. 5fps. (speed maintained for up to 510 number of JPEGs or 14 RAW images) with UDMA mode 7 card Shutter Lag 59ms Viewfinder Blackout 125ms Live View Type Electronic viewfinder with image sensor Coverage Approx. 100% (horizontally and vertically) FrameRate 29.97 fps Focusing Manual Focus (Magnify the image 6x or 16x at any point on screen) Autofocus: Quick mode, Live mode, Live Face detection mode Metering Real-time evaluative metering with image sensor Active metering time can be changed Display Options Grid overlay (x3), Histogram, Aspect ratios, Dual Axis Electronic Level File Information Still ImageType JPEG: Fine, Normal (Exif 2.3 [Exif Print] compliant) / Design rule for Camera File system (2.0), RAW: RAW, sRAW1, sRAW2 (14bit, Canon original RAW 2nd edition), Digital Print Order Format [DPOF] Version 1.1 compliant RAW+JPEG Simultaneous Rec Yes, any combination of RAW + JPEG possible, separate formats to separate cards possible Image Size JPEG: Full Frame - (L) 8688x5792, (M1) 7680x5120, (M2) 5760x3840, (S1) 4320x2880, (S2) 1920x1280, (S3) 720x480 1.3x Crop - (L) 6768x4512, (M1) 6016x4000, (M2) 4512x3008, (S1) 3376x2256, (S2) 1920x1280, (S3) 720x480 1.6x Crop - (L) 5424x3616, (M1) 4800x3200, (M2) 3616x2408, (S1) 2704x1808, (S2) 1920x1280, (S3) 720x480 1:1 Crop - (L) 5792x5792, (M1) 5120x5120, (M2) 3840x3840, (S1) 2880x2880, (S2) 1280x1280, (S3) 480x480 RAW: (RAW) 8688x5792, (M-RAW) 6480x4320, (S-RAW) 4320x2880 Movie Type MOV (Video: H.264 Intra frame / inter frame, Sound: Linear PCM) Movie Size 1920 x 1080 (29.97, 25, 23.976 fps) intra or inter frame 1280 x 720 (59.94, 50 fps) intra or inter frame 640 x 480 (59.94, 50 fps) inter frame Movie Length Max duration 29min 59sec, Max single file size 4GB Sound Files N/A Folders New folders can be manually created and selected File Numbering (1) Consecutive numbering (2) Auto reset (3) Manual reset Other Information Wireless Features GPS Custom Functions 13 Custom Functions with 47 settings Metadata Tag User copyright information (can be set in camera) Image rating (0-5 stars) LCD Panel / Illumination Yes / Yes Water & Dust Resistance Yes (equal to EOS-1N) Sound Memo No Orientation Sensor Yes Playback Zoom 1.5x - 16x Display Formats (1) Single image with information (2 levels) (2) Single image (3) 4 image index (4) 9 image index (5) Magnified view (6) 2 image compare display (7) Movie edit Slide Show Image selection: All images, by Date, by Folder, Movies, Stills, Rating Playback time: 1/2/3/5/10 or 20 seconds Repeat: On/Off Histogram Brightness: Yes RGB: Yes Highlight Alert Yes Image Erase Protection Erase: Single image, All images in folder, Checkmarked images, unprotected images Protection: Erase protection of one image at a time Menu Categories (1) Shooting menu (x4) (2) AF Menu (x5) (3) Playback menu (x3) (4) Setup menu (x4) (5) Custom Functions menu (x4) (6) My Menu Menu Languages 25 Languages English, German, French, Dutch, Danish, Portuguese, Finnish, Italian, Norwegian, Swedish, Spanish, Greek, Russian, Polish, Czech, Hungarian, Romanian, Ukrainian, Turkish, Arabic, Thai, Simplified Chinese, Traditional Chinese, Korean and Japanese Interface Computer Interface SuperSpeed USB (USB 3.0): for computer communication and direct printing Other Interface HDMI Type C, External microphone (Stereo mini jack) Canon Printer Support Canon Compact Photo Printers and PIXMA Printers supporting PictBridge Pict Bridge Yes Memory Memory Type CompactFlash Type I (UDMA 7 compatible), SD card, SDHC card or SDXC card (UHS-1 compatible) Software Browsing & Printing Software ImageBrowser EX Image Processing Software Digital Photo Professional Other Software PhotoStitch, EOS Utility (inc. Remote Capture, WFT utility*), Picture Style Editor * Requires optional accessory Batteries & Power Battery Rechargeable Li-ion Battery LP-E6N (supplied), 1x CR1616 for date & settings Battery Life Approx. 700 (73°F/ 23°C) 660 (32°F/ 0°C) Battery Indicator 6 levels + percentage Power Saving Power turns off after 1, 2, 4, 8, 15 or 30mins. Power Supply Battery Chargers AC Adapter Kit ACK-E6, Battery charger LC-E6, Car Battery charger CBC-E6 Physical Specs Body Materials Magnesium Alloy body covers Shutter Durability Rating 150,000 Operating Environment 0 – 40 °C, 85% or less humidity Dimensions Inches 6.0 x 4.6 x 3.0" (152 x 116.4 x 76.4mm) CIPA Weight 32.8 oz (930g) Accessories Viewfinder Eyecup Eg, Eg-series Dioptric Adjustment Lens with Rubber Frame Eg, Anti Fog Eyepiece Eg, Angle Finder C Camera Case Wireless File Transmitter Wireless File Transmitter WFT-E7 Compatible Lenses All EF lenses (excludes EF-S lenses), TS-E and MP-E lenses Compatible Flash Canon Speedlites (220EX, 270EX, 270EX II, 320EX, 420EX, 430EX, 430EX II, 550EX, 580EX, 580EX II, 600EX, 600EX-RT, Macro-Ring-Lite, MR-14EX, Macro Twin Lite MT-24EX, Speedlite Transmitter ST-E2, Speedlite Transmitter ST-E3-RT) Battery Grip BG-E11   Remote Remote control with N3 type contact, Wireless Controller LC-5, Remote Controller RC-6 Other Hand Strap E2, GP-E2

Description United States Patent 858,624 1,301,476 4/1919 Michael Inventors Appl. No. Filed Patented Assignee AMUSEMENT RIDE SYSTEM 12 Claims, 14 Drawing Figs. US. Cl. 104/75 Int. Cl A63g 7/00 Field 01' Search 104/83, 53, References Cited UNITED STATES PATENTS 7/1907 Reckweg 104/76 Primary Examiner-Arthur L. La Point Assistant Etaminer-Richard A. Bertsch A!t0rne '-Fulwider, Patton, Rieber, Lee & Utecht ABSTRACT: An amusement ride system for conveying passengers past a display and including a support track having inclining and declining portions. A plurality of seats are supported on trucks that are conveyed along the track and such seats swivel to face the display as the trucks pass thereby and tilt relative to the inclining and declining portions of the track to maintain the passengers seated erect. Contoured first and second orienting rails extend longitudinally of the support track and guide first and second followers which control the swiveling and tilting, respectively, of the seat. The amusement ride system may also include a safety bar for retaining passengers in the seat and actuated by a trip which strikes an actuating rail in the unloading area. 1 AMUSEMENT RIDE SYSTEM BACKGROUND OF THE INVENTION 1 Field of the Invention The present invention relates to an amusement ride system for automatically orienting a seat to face a display as it is passed thereby and for tilting such seat relative to inclining and declining portions of a supporttrack. The system also includes a safety bar that automatically opens for loading and unloading passengers. 2. Description Of The Prior Art U.S. Pat. No. 620,415 relates to railway systems which control the orientation of seats but there is, no system known to applicant which swivels the seats to facea display and also ported on posts or shafts 25 and are tilted backwardly thereon as they descend down the declining track portion 26 and are tilted forwardly as they ascent the inclining track portion 27 to thereby maintain passengers seated therein erect. Referring to FIG. 2, the seats S also swivel on the posts 25 and are turned sideways to face a display D as they are passed thereby and maintains such seats erect as such seats are conveyed over inclining or declining portions of a support'track. SUMMARY OF THE INVENTION A The amusement ride system of presentinvention is characterized by a seat that swivels and also tilts forwardly and rearwardly. A pair of orienting rails extend longitudinally of the supporting track and are followed bya pair of followers coupled with the seat. One follower swivels the seat to face displays adjacent the track as it is passed thereby and the other controls the forwardly and rearwardly tilt of the seat as such seat is conveyed over inclining and declining portions of the support track thereby maintaining such seat level. The system may also include a. safety bar for normally restricting egress from the seat and which is actuated by a follower which strikes a rail in the passenger loading area to open the safety bar for loading and unloading. Other objects and features of the invention will become apparent from consideration of the following description taken in connection with the accompanying drawings. DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial side view of an amusement ride system embodying the present invention; FIG. 2 is a partial top view of the amusement ride system shown in FIG. 1; 3 i FIG. 3 is a partially broken away side view, in enlarged scale, of the amusement ride system shown in FIG. 1; I FIG. 4 is a vertical sectional-view, partially broken away, taken along the lines 4-4 of FIG. 3; FIG. 5 is a vertical sectional view,'inf enlarged scale, taken along the lines 5-5 of F 10.3; FIG. 6 is a horizontal sectional viewtaken' along the lines 6-6 of FIG. 4; d FIG. 7 is a partial horizontal view, in enlarged scale, taken along the lines 7-7 of FIG. 4; FIG. 8 is a partial horizontal sectional view, in enlarged scale, taken from the circle designated 6 in FIG. 7; FIG. 9 is a partial side view, in enlarged scale, of the conveyance system shown in FIG. 1; FIG. 10 is a partial vertical sectional view, in enlarged scale, taken along the lines 10-10 of FIG. 4; FIG. 11 is a horizontal sectional view taken along the lines l1-11ofFIG.10; j FIG. 12 is a vertical sectional'view taken along the lines 12-12ofFIG.11; v FIG. 13 is a-vertical sectional view taken along the lines 13-13 ofFlG. 11; and FIG. 14 is a partially broken away perspective view, in decreased scale, of the orienting mechanism included in the conveyance system shown in FIG. 1. DESCRIPTION OF THE PREFERRED EMBODIMENT E Referring to FIG. 1, the amusement ride system of present invention includes a plurality of coupled together seats S mounted on trucks T which are conveyed over a pair of tubular spaced- apart support tracks 21 and 23. The seats S are supthen turn to face forwardly again. Referring to FIG. 14, the support post 25 is hollow and supports a universal joint 29 at its upper extremity, the seat 5 being mounted thereon. A swivel shaft 30 extends telescopically up through the hollow support shaft 25 and includes a universal joint 32 disposed within the joint 29. the upper portion of the shaft 30 projecting from the port 25 to mount the seat S. A follower inthe form of a wheel assembly, generally designated 31, is coupled with the swivel shaft 30 and rides along a swivel orientation rail 33' which is contoured relative to the support tracks 21 and 23 to control orientation of the seat S as it is conveyed along such tracks. The upper portion of the universal joint 29 is coupled with a follower, in the form of a wheel assembly generally designated 39. that tracks along a contoured pitch control rail 41 to manipulate the upper por tion of such universal joint and pivot the swivel shaft 30 about its universal joint 32 thereby controlling the pitch of the seat 5 as the seat is conveyed along the tracks 21 and 23. A safety bar B is pivotally attached to the lower forward portion of the seat S and is normally disposed in the passenger retaining position shown in solid lines in FIG. 9 and is actuated to the passsenger release position shown in broken lines in FIGv 9 by a follower in the form of a wheel 49 which contacts an actuating rail 53 disposed in the unloading area. Referring to FIGS. 4 and 6, the truck T includes a frame 55 which is suspended from a pair of oppositely disposed support wheels 57 and 59 that roll on the support- tracks 21 and 23 respectively. Two pairs of guide wheels 61 and 63 are suspended from the frame 55 for contacting the inner surfaces of the support tracks 21 and 23 to guide the truck T therealong. Referring to FIGS. 7 and 14, a pinion, generally designated 75, in'the form of upper and lower flanges-circularly arranged posts 81, is attached to the lower end of the. swivel shaft 30. The universal joint 32 is aligned with the support shaft universal joint 29 and the shaft section 87 projecting upwardly from the joint 43 mounts a mounting plate 89 for receiving the frame of the seat S. An opening (not shown) is formed in the wall of a fitting 95 (FIG. 4) which couples the support shaft 25 to the truck T, for receiving a pie-shaped gear portion 97 for controlling the rotation of the swivel shaft 30. The teeth of the gear portion 97 are lined with nylon 98 to reduce wear of the posts 81. I I With continued reference to FIG. 14. a pivot 'shaft 101 is pivotally mounted on its lower end to the truck frame 55 and projects up through the gear portion 47, is keyed thereto. and fixedly mounts the wheel assembly 31 on its, upper extremity. The wheel assembly 31 includes an upwardly opening U- shaped bracket, the extremities of which mount a pair of wheels 109 and 111. The wheels 109 and 111 are. spaced apart for receiving the vertical portion of the T-shaped rail 33. Referring to FIGS. 3 and 4, a lever arm 115 projects from the upper portion of the universal joint 29 and a connecting link 117 is pivotally attached thereto. As best seen in FIG. 14, the lower extremity of the connecting link 11.7 connects. with one arm 119 of a crank, generally designated 121. Theother arm 123 of the crank 121 is pivotally connected with a push rod 125 that is affixed to one end ofa rocker arm 127 which is pivotally mounted on the truck T by means of a pivot pin 129. The other extremity of the rocker am 127 is connected with an upwardly opening U-shaped bracket which mounts a'pair of wheels 133 and 135 on its opposite extremities, suchavheels being spaced-apart for receiving the vertical portion of the T shaped pitch orientation rail 41. The safety bar B is in the form of an inverted U anditslower extremities 141 are bent inwardly to form axially alignedconnecting portions which are journaled in mounting brackets (not shown. Referring to FIGS. 10 through 13, a lock frame, generally designated 145, is affixed on its rear end to the frame of the seat S by means of a mounting bolt 147. The front extremity of the frame 145 forms a fork having forwardly projecting prongs 149 and 151. The connecting portions 141 of the bar B are journaled through the legs 149 and 151. A latching bracket, generally designated 155, is mounted between the prongs 149 and 151 and is keyed to the connecting portion 141 of the safety bar B. The latching bracket 155 includes three spaced-apart rearwardly projecting prongs 159, 161 and 163. With continued reference to FIGS. 12 and 13. a pair of rollers 165 and 167 are mounted between the respective prongs 159 and 161 and prongs 161 and 163 by means of a mounting shaft 169. Referring to FIG. 12, a safety lock in the form of a cam 171 is mounted on the inner wall of the lock frame 145 by means of a pivot pin 173 and includes a forwardly projecting cam surface l75 that normally projects forwardly above the roller 165 to limit upward movement thereof and prevent forward movement of the upper portion of the safety bar B. The upper end of the cam 171 defines an abutting surface 176 that is moved ahead under the associated roller 165, as shown in broken lines in FIG. 12, when the bar B is in its passenger-inload position thereby locking said bar in such position. The lower extremity of the cam 171 is linked with a wheel frame, generally designated 179, by means of a connecting link 181 connected on its opposite ends by pivot pins 176 and 177. The connecting link 181 includes end portions 180 and 182 telescoped into opposite ends of a spring housing 183, and biased toward one another by compression spring S within such housing. The wheel frame 179 is pivotally connected to the frame of the seat S by means of a pivot pin 185 and includes a portion 187 which projects upwardly beyond such pin and to which the rear end of a latch-actuating link, generally designated 189, is connected by a bolt 188. The connecting link 189 includes a spring housing 190 into the opposite ends of which is telescoped end portions 191 and 192, the end portion 191 being connected to a latch 193 by means of a pivot pin 195 and the end portion 192 being connected to the upper portion of the wheel frame 179 by the aforementioned pin 188. The latch 193 is pivotally mounted on the frame 145 by a mounting pin 197 and the forward extremity of such latch forms an arcuate forwardly opening cutout 201 for receiving the roller 167. The lower portion of the wheel frame 179 is biased forwardly around the mounting bolt 185 by means of a tension spring 205 to thereby maintain the latch 193 rotated counterclockwise as viewed in FIG. 13, and the latching bracket 155 rotated clockwise to urge the bar B to a normally closed position. Referring to FIGS. 1,3 and 4, the trucks T of the consecutive seats S are connected together by means of tubularshaped connecting beams 211. The forward ends of the connecting beams 211 are received within respective clevises 213 and connecting pins 215 are inserted through aligned vertical bores. The rear extremity of the connecting beams 211 are received in forwardly facing clevices 214 in the front portion of the trucks T and vertical pins 216 are inserted through vertical bores in the respective clevises and rear extremities of the connecting beams. Referring to FIGS. 4 and 5, the connecting beams 211 include downwardly projecting webs 217 which have resilient platens or skirts 219 fastened to their lower peripheries. Drive motors 231 are provided below the conveyance system and include drive pulleys 233 on which endless belts 235 are received, such belts 235 being threaded around idler pulleys 237. A similar pair of pulleys 238 and belt 239 are supported on the opposite side of the skirts 219 and cooperate with the belts 235 to frictionally sandwich the skirts 219. A pair of followers in the form of horizontal stabilizing wheels 241 and 243 are mounted in spaced-apart relationship to the underside of the seat 8. The wheels 241 and 243 engage the side of the rail 53 and a second stabilizing track (not shown) while the respective seats S are in the unloading area to stabilize the seats against tilting and rotating while passengers are unloading and loading. In operation, the personnel conveyance system of present invention is started by actuating the drive motor 231 to feed the skirts 219 suspended from the connecting beams 211 by the respective belts 235 and 239 thus advancing the trucks T on the support tracks 21 and 23. As a seat S is brought into the loading and unloading area, the wheel 49 rides into the rail 53 and pivots the wheel frame 179 rearwardly on its mounting bolt 185. Such rearward rotation of the wheel frame 179 pulls the lower extremity of the cam 171 rearwardly to enable the roller 165 to clear the cam surface 175 and roll up the front face 301 of the cam 171. Since both the links 181 and 189 can be compressed against their compression springs there is allowance for relative movement between the wheel frame 179 and the cam 171 to enable the cam surface 175 to be moved clear of the roller 165 before the latch 193 commences rotation. Referring to FIGS. 9 and 13, rearward rotation of the lower portion of the frame 179 drives the latch connecting link 189 forwardly thus pivoting the latch 193 clockwise around its mounting pin 197 to raise the rearward extremity of the latching bracket thus pivoting the connecting portion 141 of the bar B counterclockwise and moving the bar to the locked open position shown in broken lines in FIGS. 9 and 12. As described above, the cam 171 is initially rotated to move the surface 175 clear of the roller and such roller travels up the face 301 of the cam 171 as the bar B is moved to its open position. During the last portion of its upward movement the roller 165 rotates the cam 171 slightly clockwise against the force of the springs in the link 181 to move the roller above the top of the cam 171. When the roller 165 clears the top of the cam 171, such cam will rotate slightly counterclockwise to move the top surface 176 under the roller 165 to hold the bar B in its locked open position. While the bar B is in such position, passengers may enter the seat S and be seated therein. The stabilizing rails extend throughout the loading area and are engaged by the wheels 241 and 243, respectively. to stabilize the seat S during loading. When the seat reaches the end of the loading area, the wheel 49 will drop off the rail 53 thus enabling the tension spring 205 to pull the lower portion of the wheel frame 179 forwardly. Such forward movement of the lower portion of the frame 179 will rotate the cam 171 clockwise thus clearing its top surface 176 from the path of the roller 165 thus freeing the bar B to close. The latch 193 will then be rotated counterclockwise thus pushing the rearward extremity of the latching bracket 155 downwardly and rotating the connecting portion 141 of the bar 8 clockwise thus moving the bar B to the position shown in solid lines in FIG. 9. The tension spring 205 is sufficiently resilient to avoid the bar B striking anyone in its closing path with sufficient force to cause injury. When the lower portion of the wheel frame 179 reaches its forward position, the lower extremity of the cam 171 will be pushed a sufficient distance forward to maintain the cam surface partially disposed over the roller 165 thus providing a safety latch to prevent passengers in the seat S from moving the bar B forwardly to exit the car while it is in motion. As the seats S are conveyed around the tracks 21 and 23. the contoured orienting rail 41 will guide the wheel assemblies 39 to maintain the respective seats S erect. Referring to FIG. 1, when the seats S are conveyed down the decline 26. the posts 25 are inclined upwardly and forwardly but the track 41 is contoured to tilt the seats backwardly on such posts to maintain them level. Such rearwardly tilting of the seats 5 is accomplished by having the rail 41 curve away from the adjacent support track 21 (FIG. 6) whereby the wheel assembly will be pivoted on its pivot pin 129 pushing the crank arm 123 (FIG. 14) inwardly and lowering the arm 119 to pull the rear end of the lever arm 115 downwardly to tilt the associated seat S backwardly. During ascent up the incline 27 the rail 41 will be curved inwardly away from the adjacent support track 21 thereby causing the crank 121 to be rotated to lift the rear end of the lever arm 115 and tilting the associated seat 5 forwardly on the support post to maintain it level. Referring to FIG. 2, when the individual seats S approach a display D the seats S are pivoted sideways and face such display. Pivoting to the right as depicted in FIG. 2, is accomplished by means of the orienting rail 33 (FIG. 6) being curved toward the adjacent support track 23 thereby causing the gear portion 97 to be rotated counterclockwise rotating the swivel shaft clockwise and pivoting the associated seat S to the right. Beyond the display D the seats 5 are pivoted to face forwardly to orient the passenger to view upcoming displays which may be disposed on the left side of the tracks 21 and 23. To pivot the seats S to the left the orienting rail 33 will curve away from the adjacent support track 23 to swivel the seat S accordingly. From the foregoing it will be clear that the amusement ride system of present invention provides a seat which automatically rotates for convenient viewing of displays and tilts to maintain a level orientation. Further, a safety bar is provided which automatically locks into a passenger retaining position when the seat is not in the loading area thus preventing passengers from standing up in the seat or exiting the seat and endangering their persons. Various modifications and changes may be made with regard to the foregoing detailed description without departing from the spirit of the invention or the scope of the following claims. We claim: 1. An amusement ride system fongonveying passengers by a display, said ride comprising: i a support track extending adjacent said scene and including an inclining portion and a declining portion; first and second orienting rails extending longitudinally of said support track and contoured with respect thereto; a truck mounted on said support track and including a joint rotatable about a horizontal axis extending transversely of said support track; I a seat mounted on said joint, said seat being pivotable relative to said truck to orient passengers seated therein for viewing said scene as said seat is passed thereby; orienting means including a first follower coupled with said seat for following the contour of said first orienting rail to progressively pivot seat to face said display as said seat is moved thereby, said orienting means including a second follower coupled with said joint for following the contour of said second orienting rail and mechanically manipulating said joint to position said seat for positively maintaining said passengers seated erect while said seat is conveyed over inclining and declining portions of said support track; and drive means for driving said truck on said support track. 2. An amusement ride system as set forth in claim 1 that includes: a hollow support shaft interposed between said truck and said seat; a swivel shaft projecting upwardly through said hollow support shaft and coupled with said seat and first follower to pivot said seat on said support shaft. 3. An amusement ride system as set forth in claim'l that includes: a second support track extending longitudinally of said first mentioned support track; wherein said truck includes: a pair of support wheels supported on top of said respective first and second support tracks; and g a first pair of horizontally spaced-apart guide wheels for engaging 'the sides of said first support track, a second pair of horizontally spaced-apart guide wheels for engaging said second support track and cooperating with said first pair of guide wheels to guide said support assembly on said first and second support tracks. 4. An amusement ride system as set forth in claim 1 that includes: a stabilizing rail extending longitudinally of said support track; and a third follower mounted on said seat for following along said stabilizing track to stabilize said seat. , 5. An amusement ride system as set forth in claim 1 wherein said drive means includes: a skirt mounted on said truck and extending longitudinally of said support track; a motor including a drive pulley for engaging said skirt to drive said skirt past said motor. 6. An amusement ride for automatically loading passengers from a loading area, said ride comprising: a support track; a truck mounted on said support track; a seat supported on said truck; an actuating rail disposed in said passenger-loading area; a safety bar including a horizontal retaining portion and a connecting portion, said bar being pivotal from a retaining position with said retaining portion disposed over the lap of a passenger sitting in said seat to a release position with said portion pivoted forwardly from said retaining position to release passengers from said seat; means for pivotally mounting said connecting portion to said chair; a latching bracket mounted on said connecting portion and including a pivotal element on its projecting end; a latch pivotally mounted, intermediate its ends, on said seat, one end of said latch forming a second pivotal element for cooperatively engaging said first pivotal element; a safety bar actuating mechanism pivotally mounted on said chair, coupled with the extremity of said latch opposite said one end and including a follower for engaging said actuating rail to rotate said latch thereby pivoting said latching bracket to pivot said bar to its release position; and drive means for driving said truck along said support track. 7. A personnel conveyance system as set forth in claim 6 that includes: biasing means for biasing said bar to its closed position. 8. An amusement ride system as set forth in claim 6 that includes: a lock for locking said safety bar in said retaining position. 9. An amusement ride system as set forth in claim 6 that includes: a lock pivotally mounted on one extremity to said seat and including a cam surface normally disposed in the path of said latching bracket to resist movement of said bar from said release position; a link connecting said lock with said actuating mechanism for moving said cam surface out of the path of said lever when said follower engages said rail. 10. An amusement ride system as set forth in claim 6 that includes: a lock for locking said safety bar in said release position and responsive to engagement of said follower with said rail to lock said bar in said release position and responsive to disengagement of said follower from said rail to unlock said bar from said release position. 11. An amusement ride system as set forth in claim 6 wherein: said support track includes inclining and declining portions and extends adjacent a display; and wherein said system includes; support means on said truck for mounting said seat for rotation to face said display as said seat is passed thereby, said support means including a joint pivotable about a horizontal axis extending transversely of said track; first and second orienting rails extending longitudinally of said support track and contoured relative thereto; orienting means including a second follower for following said first orienting rail and coupled with said seat to rotate said seat to face said display as said seat is passed thereby and a third follower for following said second orienting rail and coupled with said joint to manipulate said joint and orient said seat to maintain passengers therein erect while said seat is moved up said inclining portions and down said declining portions. 12. An amusement ride system. as set forth in claim 6 wherein said drive means includes: a skirt depending from said trucks and extending longitudinally of said support track; a drive motor mounted adjacent said support track and including a pulley for frictionally engaging said skirt to pull said truck past said motor.

Through October 26 Damian Elwes: Artist Studios — From Picasso to Kusama I recently had the great pleasure to meet the artist Damian Elwes, and to see his vivid and witty and fascinating paintings currently on show at Modernism. Damian, who for decades has been studying and obsessed with artists’ studios, has painted, imagined, recreated, and vividly depicted artists' studios around the world. He captures them in an almost cinematic style, and depicts major works in the vernacular of the artists. They represent moments of inspiration, but in particular they paint a portrait of the (unseen) artist in full creative frenzy. In the Modernism show, his collection includes the imagined studios of Willem de Kooning, Paul Gauguin, David Hockney, Ellsworth Kelly, Gustav Klimt, Yayoi Kusama, Roy Lichtenstein, Kerry James Marshall, Henri Matisse, Pablo Picasso, Andy Warhol, and Jonas Wood. Two years ago at Modernism, he presented studios of Frida Kahlo, Cy Twombly, Lucien Freud and Richard Diebenkorn, to great acclaim. The centerpiece and the most impressive piece of the current show is a special installation of the monumental eight-panel painting, ‘Picasso’s Villa La California’. Room-size and full of detail and humor and insight, it is like stepping into Picasso’s world. Immersive. Meticulous. Wonderful. Go now. It is a rare and special experience. Picasso's studio “I choose to focus on creativity and on visionary people. For me, the studio is a metaphor. I am able to learn from watching artists making art. Why have I gone to great lengths to make studio paintings and to visit studios all over the world with their untold stories?” Damian Elwes “Instead of going to art school, I spent two years searching for artist studios in Paris. I asked the artists if I could make a watercolor or paintings of their workplaces. Meanwhile, I was able to learn from watching them make art.” — Damian Elwes Hockney's studio Damian Elwes: Artist Studio  Damian, who now lives in Santa Monica, is from a noble lineage of English artists and portrait painters, and started painting when his father asked him to ‘fill in the sky’ of a portrait while the sitter took a break. But it was not until 1984 when Elwes was living in New York that he was first encouraged and dared and challenged to paint large-scale by Keith Haring. It was at this time that Damian hung out with Haring, a renegade graffiti artist at that time, lived in his studio, and committed paint to walls and canvas and surfaces around New York. His first gallery show in London was a groundbreaking exhibit of the works of Haring and Jean-Michel Basquiat at the height of their fame and creativity. Warhol's studio Gauguin's studio Matisse's studio Artist studios, familiar from the painting studios of his father and his grandfather, became an Elwes obsession. Soon he was in Paris studying Delacroix and Picasso and every artist who ever painted in Paris. And over the following decades (including a legendary time when he and his family lived in the remote and lovely Colombian rainforest)…Elwes was visiting, photographing, studying and painting them. He looks at ambiance, view from windows, light, ephemera and studies the paintings the artists worked on in these specific studios. His paintings become a vibrant and evocative dialogue with the artist, and comment on a continuous era of creativity and ideas and evolution of an artist. Soon he was showing in Los Angeles, and among his early clients were Mick Jagger, Al Pacino, Anthony Hopkins, and Pierce Bosnan. In 2007, after seven years of painting in Colombia, Elwes studied and researched Picasso’s Bateau Lavoir, a time when Picasso was at his most innovative. “I am fascinated with everything that goes into creating a work of art,” said Elwes. He’s a fervid researched and studies every photograph and paintings and belongings and writing of an artist before embarking on a studio painting. He has visited and reinvented/ reimagined the Collioure studio of Matisse, as well as Villa La Reve where Matisse lived and painted. Next on his agenda: Damian Elwes has been invited to work and live for a year in Cy Twombly’s former studio and residence near Rome. I can't wait to see the works he creates there. DeKooning's studio Ellsworth Kelly's studio Roy Lichtenstein's studio Damian Elwes has now studied and painted the studios of artists ranging from Claude Monet to Roy Lichtenstein and Cindy Sherman and John Baldessari. Elwes has developed a cult following, in part because the paintings unveil and reveal and recontextualize the artists and their place of work and setting. They capture historically important moments, within a framework that is accurate and architecturally correct. Even the view from the windows is period accurate. “In historical terms, Elwes’ canvases can be seen as an invaluable contribution to the understanding and investigation and revelation of some of the greatest artists of the twentieth century, “ said gallery owner, Martin Muller. ‘They are immersive and they capture a time, a period, a life, and moments of brilliance and breakthroughs. It’s daring. Elwes does it with great admiration, and often with a dash of wit and humor.” Joans Wood's studio Klimt's studio Kerry Marshall's studio Yayoi Kusama's studio Modernism Gallery — The Architecture Architect statement: AIDLIN DARLING DESIGN “The design of the new MODERNISM Gallery seeks to honor both the history of the existing structure and the origins of MODERNISM itself. The new façade of the gallery was inspired by the lithographs of El Lissitsky, one of the first artists to be shown in the thirty-plus year history of the Gallery. A series of steel frames, planes, and lines are sculpted to create a large street front viewing portal and the primary entry into the gallery. Within, the design creates a highly intentional and complimentary dialogue between the original structure of board-form concrete walls and wood ceiling members, and the new, crisp, white modern planes that define the walls for displaying art. The result is intended to create a highly inspirational venue for the viewing of experimental art while pioneering one of San Francisco's up-and-coming art districts.” — Joshua Aidlin, Principal, Aidlin Darling Design Frida Kahlo's studio Cy Twombly's studio René Magritte's studio About Modernism Gallery Founded in 1979, Modernism has since presented more than 375 exhibitions, historical and contemporary, in media ranging from painting to photography, sculpture to performance, by an international roster of artists. Martin Muller of Modernism Modernism’s 1982 ground-breaking Andy Warhol exhibition — the first time the Pop artist’s work was shown on the West Coast. The show turned out to precede California’s enthusiasm for Pop art. Only one painting sold, for a minute $20,000. Martin Muller, who has a broad international following, has mounted for than eighteen retrospectives of the Russian avant-garde. Historical exhibitions encompass concepts including Dada, Cubism, Surrealism, Vorticism, German Expressionism, and foremost, the Russian Avant-Garde 1910-1930. The contemporary exhibits feature rotating shows, six to seven weeks in duration, of the nearly 50 gallery artists—including various representational and abstract modes, sociopolitical, and conceptual works—presented at both Modernism and Modernism West, as well as at art fairs in the United States and Europe. Modernism publishes collectible books, monographs, catalogs, and fine art editions. Martin Muller is noted for his discernment and collections of art and design books, and for his eclectic gallery publications. His art and design book collection, legendary, now includes 30,000 books. Keith Haring's studio CONTACTS: Modernism Martin Muller, owner Danielle Beaulieu, Director 724 Ellis Street San Francisco, CA 94109  www.modernisminc.com Instagram: @modernisminc Damian Elwes is a British artist who lives and works in Santa Monica. His work has been exhibited in galleries around the world, and he was recently the subject of a retrospective at the Musée en Herbe in Paris. www.damianelwes.com Instagram: @damianelwes Picasso's Bateau Lavoir studio

Landowners who are managing their land for white-tailed deer may consider planting food plots to provide a supplemental food source. Food plots should never be considered a substitute for managing the native vegetation to provide quality food sources. In situations where food plots would contribute to deer management objectives, the plots need to be established and maintained properly. | White-tailed deer management This deer conservation guide is one in a series developed jointly by MU Extension and the Missouri Department of Conservation. Robert A. Pierce II Fisheries and Wildlife State Specialist School of Natural Resources Emily Flinn Resource Scientist Missouri Department of Conservation Paul Lowry and Brad Mormann Private Land Conservationists Missouri Department of Conservation Landowners who are managing their land for white-tailed deer may consider planting food plots to provide a supplemental food source (Figure 1). On some properties, establishing and maintaining food plots can provide supplemental food and nutrition for deer, but food plots should never be considered a substitute for managing the native vegetation to provide quality food sources. In situations where food plots would contribute to deer management objectives, the plots need to be established and maintained properly. Figure 1. Food plots can provide supplemental food sources for deer.   Deer nutrition Deer are selective browsers; therefore, a variety of foods make up their diet, including broad-leaved herbaceous plants (forbs), woody plants, grasses, mast (acorns, fruits and berries) and mushrooms. No one food dominates a deer’s diet throughout the year because deer select foods based on plant availability, palatability and nutritional content, all of which vary throughout the year. The nutritional needs of deer also vary throughout the year. During the spring and summer, pregnant and lactating does and antler-growing bucks need more protein in their diets. During the fall and winter, deer have greater energy demands and therefore need more carbohydrates. Food plots can be planted to provide supplemental nutrition during times of stress, such as when does are pregnant or lactating and when bucks are growing antlers. Stress periods often coincide with times of the year when native vegetation is lacking or poor in quality, typically from late summer to early fall and from mid- to late winter. Refer to MU Extension publication G9487, Nutritional Requirements of White-tailed Deer in Missouri, for more complete information on deer nutrition. Food plot considerations Before establishing a food plot for deer, consider these questions as you determine what is best for your property: What management objectives will a food plot accomplish on your property? Will the forage be available during stress periods and provide nutritional benefits? Will the forage benefits justify the required costs and effort? What areas on the property are good locations for food plots? Are deer likely to use the food plot? Do you have the necessary equipment to establish and manage food plots? Set objectives In most cases, managing existing native vegetation is a more practical and cost-effective way to increase the quantity and nutritional quality of available forage, as establishing and maintaining food plots can be expensive. However, if food plots are warranted, the first step is to determine the objectives for the food plots, as the objectives will guide all of the establishment and management decisions. In addition to providing supplemental nutrition during stress periods, food plots can be established to to improve hunting or viewing opportunities, or to alter deer movement patterns. Determine the cost Establishing and managing a food plot requires a financial investment. Depending on the objectives, establishing a food plot can cost up to $200 an acre in seed, herbicide, fertilizer and lime, in addition to the costs for equipment, labor and fuel. The expense of managing a food plot from year to year will vary based on its size, annual fertility needs, weed control and the seed planted. If properly managed, some food plots may provide supplemental nutrition for over three years. The cost of food plot establishment can be reduced in various ways. Cost-saving possibilities include partnering with nonprofit wildlife organizations that may provide seeds for planting, buying seed in bulk as a group of landowners or a cooperative, or working with a neighboring landowner and sharing equipment that can be used in establishing the plots. Identify the location Areas where deer travel and areas near habitats that provide protective cover are ideal locations for food plots. Food plots can also be established in woodland openings or adjacent to forest edges, idle areas or open fields. Other possible food plot locations include along rights of way, logging decks, fire lines and woodland roads (Figure 2). Food plots are commonly established adjacent to a forested edge. These areas can be made even more attractive to deer and other wildlife through the development of a transition zone or field border with edge feathering or shrubs (Figure 3). Because of the possibility of increased poaching or deer-vehicle accidents, a food plot should not be located next to a public road. Also, to prevent unnecessary issues with neighboring landowners and hunters, avoid planting a food plot along a property boundary.   Figure 2. Woodland openings, logging roads and right-of-ways provide excellent locations for establishing food plots.     Figure 3. When establishing a food plot along a woodland edge, locate it 30 to 50 feet from the tree line and conduct edge feathering practices to allow a soft edge and transition zone of forbs, shrubs and vines to develop around it.   Consider size and shape Topography and the surrounding habitat will dictate the type and amount of acreage that should be planted to a food plot. However, evenly distributing food plots over 2 to 5 percent of a property, using a combination of warm- and cool-season forages is generally recommended.  Recommended sizes vary from ½ to 5 acres depending on the forages being used and the configuration of the property. Generally, larger food plots of 3 to 5 acres are more beneficial for deer. Smaller food plots can be useful but tend to produce less forage due to browsing pressure and shading. Food plots larger than 5 acres can be designed with corridors or hedgerows of trees planted at 50-yard intervals to create visual breaks and provide screening cover (Figure 4). The size of a food plot may also be determined by access, size of equipment or location on the property. For example, small isolated fields may be available, but poor access limits the size of equipment that can reach them. Smaller equipment, such as an all-terrain or utility-terrain vehicle (ATV or UTV), might be the only means of maintaining a food plot in these isolated areas (Figure 5). The shape of a food plot will often depend on the area’s topography. Food plots can be rectangular, square or irregular, and the border can have edges that are wavy or straight. A hub-and-spoke design, where several food plots are established as lanes beside areas of early successional vegetation, can also be used to increase hunting opportunities (Figure 6). Large rectangular or square food plots could be established in areas of high deer density to reduce browsing pressure and increase the chance of forage establishment (Figure 7). Figure 4. Visual barriers and screening cover such as hedgerows or corn plantings provide security for deer and can result in more deer sightings and hunting opportunities.     Figure 5. Consider what equipment and implements are available when planning a food plot, as they can affect the plant species that can be successfully planted, as well as the size and location of a food plot. For example, remote plots can be inaccessible for some equipment, such as large tractors, planters and other implements.   Figure 6. Different food plot designs can achieve various goals. The hub-and-spoke design simultaneously provides natural habitat for cover and food plot strips that provide hunters with shooting lanes.   Figure 7. Plots can be planted with a grain crop and a cool-season forage such as winter wheat and clover. Larger plots have a better chance of withstanding heavy browsing pressure.   Select forages Selecting the right combination of forages or plant mixtures to use in a food plot is important. Various combinations of warm-season and cool-season forages that are either annuals or perennials can be considered (Table 1). The type of planting that is suitable for an area depends several factors: Soil fertility (see Food plot establishment section) Sunlight availability Soil drainage Equipment available Deer herd density Surrounding land-use practices Planting a variety of cool- and warm-season forages will offer a diversity of foods that will be used at various times of the year. Select forages that are palatable and that provide nutrition during stress periods for deer. Table 1. Food plot forages commonly used in Missouri. Forage Growing season Life span Soil pH Seeding rate (pounds per acre) Planting date Additional information Alsike clover Cool Perennial 6.0–6.5 Broadcast 4–6 August or April Short-lived perennial that tolerates wet, heavy soils and flooding better that other legumes. Best to include in a mixture with wheat or oats. Arrowleaf clover Cool Annual 6.0–6.5 Broadcast 10–15 September Grows best on well-drained soils. Can be planted with winter wheat and oats. Crimson clover Cool Annual 5.5–6.5 Broadcast 20–25 July to November Excellent forage that can be planted with winter wheat or oats. Forage radish Cool Annual 6.0–6.5 Broadcast 12 or drill 7–10 August to September Plant on a well-drained seedbed in late August to early September, 8–10 weeks before a frost. Kale Cool Annual 5.5–6.5 Broadcast or drill 4–5 August to September Cold-hardy; does not thrive in hot weather. Ladino clover Cool Perennial 6.0+ Broadcast 1–3 September or February to March Tolerates wetter soils. Best to plant with annual grain. Oats Cool Annual 5.8–6.5 Broadcast 80–120 August to September One of the most palatable small grains. Easy to establish. Can tolerate heavy grazing but cannot tolerate poor drainage or drought. Rape Cool Annual 5.3–6.8 Broadcast 4–9 or drill 2–6 August to September Requires good soil drainage. Best planted in strips rather than in a mixed seeding where other plants may shade it. Red clover Cool Perennial 5.5+ Broadcast 10 August or April Adapted to poorly drained, shallow or infertile soils. Will not tolerate intense, long-term browsing or drought. Rye (grain) Cool Annual 5.8–6.5 Broadcast 90–120 August to September Good for erosion-prone areas. Tolerates acidic, poor soils. Turnip Cool Annual 6.0–6.5 Broadcast or drill 3–6 August to September Deer eat these after a deep freeze. Wheat Cool Annual 5.8–6.5 Broadcast or drill 100–150 August to September Highly palatable to deer. Good mixed with red, crimson, alsike or arrowleaf clover. Alfalfa Warm Perennial 6.5–7.5 Broadcast 20–25 or drill 12–15 August or April Alfalfa produces and persists poorly on shallow or poorly drained soils and should not be planted on such sites. Sensitive to competition and heavy browsing pressure. Requires precise soil fertility conditions.  Corn Warm Annual 5.8–7.0 Drill 10–15 April to June Low in protein but high in carbohydrates. Susceptible to drought. Requires good soil and fertilization.  Cowpea Warm Annual 5.2–7.5 Broadcast 60–90 or drill 40–60 May to June Susceptible to overgrazing. Can tolerate drought, low fertility and acidic soil conditions. Grain sorghum Warm Annual 5.6–7.0 Drill 8 May to June Seed heads are preferred by deer after the first freeze. Lablab Warm Annual 5.5–7.5 Drill 15–20 May to June Cannot tolerate wet soils or heavy deer browsing. Soybean Warm Annual 5.5–7.0 Drill 50–75 May to June Sensitive to deer browsing, especially the first 30–45 days. For more information, refer to MU Extension publication G4652, Seeding Rates, Dates and Depths for Common Missouri Forages, Annual vs. perennial Annual plants germinate, grow, flower and produce a seed in one growing season. Perennial plants germinate, grow, flower and produce seeds on a continual basis over multiple years. Most food plot forages are annuals or perennials, but some can be biennials. Plants such as red clover have a biennial life span and generally live two years, growing roots, stems and leaves the first year, and flowering and then dying the second year. Cool-season vs. warm-season Plants used in a food plot can be classified as either cool-season or warm-season. Cool-season, or “green browse,” food plot forages — such as clover, winter wheat and rape — grow during the fall and spring when temperatures are cooler. These forages provide sources of quality nutrition when other foods may be limited. They help bucks recover from the stress associated with breeding season and can increase hunting opportunities on the property. Annual grains such as winter wheat or oats planted alone or with various clover varieties will provide a source of nutritious foods during the late fall and winter (Figure 8). Planting a variety of cool-season forages will ensure that adequate nutrition is available during the early fall when warm-season forages may be lacking and through late winter when green browse is at a premium. Crops in the Brassica genus can also be very attractive to deer. Brassica species include turnips, rape, radishes, kale and canola (Figure 9). Warm-season forages are typically planted in the spring (late April through May) after the threat of frost has passed and before the drier summer months. Both corn and grain sorghum produce grains that are high in carbohydrates and fat for energy and are very attractive to deer in the fall and winter. Soybeans are a warm-season crop that is heavily consumed as green forage in the summer and whose beans are used throughout the winter. Warm-season forages can supply supplemental nutrition that is important for lactation, fawn growth and antler development. A variety of native forbs and legumes typically make up a large percentage of a deer’s diet during the warm, summer growing season. Thus, warm-season plots can also be planted that contain a variety of high-quality legumes and other forbs to supplement naturally occurring vegetation. Figure 8. Adding legumes, such as various species of clover, with plantings of winter wheat or oats can provide a nutritious source of food during fall and winter.   Figure 9. Plants in the Brassica genus, including turnips (pictured), rape, radishes, kale and canola, can be used in food plots.   Mixtures Planting mixtures of forage can provide multiple benefits (Table 2). One benefit is nutritional, as mixtures provide diverse nutrients and potentially lengthen the availability of forage. In addition, planting mixtures provides an insurance of sorts: if one species doesn’t establish, the other may, which generally prevents a total food plot failure. The use of cool-season perennial forages in various mixtures can be beneficial. Perennial clovers and many other legume species are a preferred food for deer and provide excellent nutrition. Species such as crimson clover, red clover and ladino white clover are commonly planted in mixtures with winter wheat, oats or both to provide a nutritious source of protein through the winter months. Also, the grain crop often protects the legume from drought or overgrazing, while the legume provides needed nitrogen for the grain. This relationship between the plants increases the chances of planting success and decreases the need for fertilizer. Table 2. Food plot mixes commonly used in Missouri. Forages Growing season Life span Soil pH Seeding rate (pounds per acre) Planting date Additional information Alsike clover, small grain (wheat, oat, rye) Cool Annual, perennial Low pH well tolerated Broadcast alsike 4–6, small grain 50 August to September Tolerates wet soil but not hot, dry conditions. Handles browsing pressure well. Rape, kale, turnip Cool Annual 6.0+ Broadcast 2 each or drill 1 each August to September Frosts on mature plants cause sugar levels to increase, which increases palatability. Rye (grain), white clover Cool Annual, perennial 5.8–6.5 Broadcast rye 50, white clover 5 August to September Rye (grain, not to be confused with ryegrass) allows clover to establish. Red clover, arrowleaf clover, small grain (wheat, oats, rye) Cool Annual, perennial 5.5+ Broadcast (Drill) red clover 5–7 (5), arrowleaf clover 5–7 (5), grain 50 (30) August in the north; September or early March in the south Disk in August and fertilize in September according to soil test recommendations. Clovers will germinate quickly and reseed. Crimson clover and wheat Cool Annual, reseeding clover 5.8–7.0 Broadcast (Drill) crimson clover 15 (10), wheat 50 (40) Late August or early September Crimson clover is annual clover that is an excellent companion plant and will reseed. Mixture tolerates a variety of soil conditions. Alyceclover, American jointvetch Warm Annual 5.5–6.5 Broadcast 10 each May or June Provides good forage for deer but is susceptible to drought. Grain sorghum, forage bean Warm Annual 5.6–7.0 Drill grain sorghum 7, beans 50 May to June Provides a combination of warm- and cool-season food sources.   Food plot establishment Once you have decided on the size of the food plot, you can ensure the success of the planting by determining soil fertility needs, preparing the seedbed and planting the forage at the recommended rates and depths. Keep in mind that establishing food plots on highly fertile soils and areas with flat topography will minimize establishment cost and reduce potential problems associated with soil erosion. Determine soil fertility The quality and overall fertility of the soil will influence the ability of the plants to persist in the stand and can also indirectly affect the nutritional quality of the forages. The nutritional quality of the vegetation is a byproduct of the soil fertility level, which is therefore an important factor to consider before establishing a food plot. Soil testing At least three months before planting, have the soil tested to determine whether any fertilizer or liming is required for the seeding mixtures you plan to use (Figure 10). A soil test will determine if fertility and pH need to be modified before planting. Collecting soil samples involves gathering four to six random samples of soil, about 4 inches deep, throughout the food plot. Be sure to collect samples of soil from several locations in the field. Mix together all the samples from within a single food plot and allow the soil to dry before sending it to a local MU Extension center or directly to the Soil and Plant Testing Laboratory for analysis. The soil test report will provide fertilizer and lime recommendations based on the vegetation to be planted. For more information on collecting and submitting soil samples, visit the MU Extension Soil and Plant Testing Laboratory website, extension.missouri.edu/programs/soil-and-plant-testing-laboratory/spl-soil-analysis. Figure 10. Collect samples and have the soil tested to determine fertility needs of area before establishing a food plot.   Key soil nutrients The most important nutrients that plants need for growth are nitrogen (N), phosphorus (P) and potassium (K), which are the basis of most fertilizers. A soil test report will provide recommended fertilizer amounts and time of application that will ensure success. Typically, legumes have a high P and K requirement and do not need nitrogen because they “fix” nitrogen from the bacteria that occur on the nodules of their root systems. Nitrogen is the key ingredient in plant proteins. It helps increase plant growth, palatability and crude protein levels. Plants that aren’t getting enough nitrogen often have light green to yellow-green foliage. Grasses and grain crops are often the first to suffer from nitrogen deficiency and greatly benefit from timely nitrogen applications. Phosphorus is essential for plant root and leaf growth. Without enough phosphorus, plant growth is stunted and foliage often is purplish. Potassium helps plants regulate water, absorb nitrogen, perform photosynthesis and transport nutrients. This important nutrient also increases root growth and drought tolerance. Potassium deficiency often decreases protein availability and causes leaf edges to turn yellow to pale brown. Soil pH A soil’s pH is a measure of its overall acidity. It is measured on a scale of 1 to 14, with a pH of 7 being neutral. Lower pH values are indicative of an acidic condition and higher values of an alkaline, or basic, condition. A soil pH of 6.5 to 7 is recommended for most food plot plantings. Soil pH can influence plant growth, a plant’s ability to fix nitrogen, and the overall availability of nutrients to the plant. For instance, phosphorus and calcium — two important minerals necessary for antler growth — become less available to plants in acidic soils. These conditions can be adjusted by incorporating the recommended rates of agricultural lime into the soil about six months before planting. Prepare seedbed A clean, well-disked seedbed is ideal for establishing small seeded plants such as clovers and brassicas. The seedbed should be firm and free of vegetation before it is planted. Depending on the site, a recommended herbicide may need to be applied to control existing perennial grasses, such as tall fescue, and other vegetation before disking or using a no-till drill. If these grasses are not controlled, they will eventually outcompete the food plot plants. A variety of recommended herbicides (broad-spectrum or grass-specific) and various formulations can be used, depending on the circumstance and the vegetation that is being controlled. For example, if tall fescue is present in the food plot area, spray 1.5 to 2 quarts of glyphosate per acre in the fall before a spring planting or in the spring before a fall planting. Before spraying the area, the grasses should be burned, grazed or mowed so that the field is free of thatch, which would block much of the herbicide from the growing grass. About two weeks after the herbicide application, the food plot can be no-tilled drilled or disked for planting. Calculate pure live seed Pure live seed (PLS) is a measure of the actual percent of the crop seed in the bag that is expected to germinate once planted. It can be used as an indirect measure of the quality of seed. PLS can be affected by the amount of inert matter, the percentage of pure seed and the germination rate. Although two seed bags of the same plant species may weigh the same, each may not have the amount of pure live seed needed to plant the same number of acres. The seeding rate will differ depending on the amount of PLS each seed bag contains. To calculate the amount of PLS a bag contains, multiply the pure seed percentage by the germination percentage listed on the bag’s seed tag. Pure seed × Germination = Pure live seed Example 0.98 × 0.80 = 0.784 (78.4 percent) To calculate the actual seeding amount based on the PLS, divide the desired seeding rate by the PLS. For example, if the desired seeding rate is 8 pounds per acre and the PLS of the seed is 78 percent, the actual seeding rate will be 10.2 pounds per acre. Desired seeding rate (pounds per acre)/Pure live seed (percentage) = Actual seeding rate (pounds per acre) Example 8/ 0.78 = 10.2 Seeding rates of forages used for food plots are generally similar to those recommended for agricultural production. However, reducing the seeding rates for various mixtures will promote the growth of annual forbs and other broad-leaved plants that can enhance the plant diversity and value of the food plot for other wildlife, such as bobwhite quail and songbird species. Inoculate legume seed Legumes are plants that have adapted a symbiotic relationship with certain species of bacteria. The bacteria attach to the legume’s roots, where nodules form. These nodules allow the bacteria to extract nitrogen from the air for the plant’s use. In exchange, the plant provides energy and nutrients for the bacteria’s growth. Both the bacteria and the plant benefit from this relationship. As a result of this relationship, legume seed must be inoculated with a bacterium to ensure that it germinates. The sticking agent in the inoculant adheres the bacterium to the seed. Different legumes require different strains of bacteria, so be sure to buy the correct inoculant for the seed. Inoculant is usually available from the seed dealer. Follow directions on the inoculant bag for application. Preinoculated legume seed is available, but its PLS may be low because the seed coating can account for 20 to 30 percent of the material in the seed bag. Select planting methods Follow recommended planting dates, seeding rates and depths to ensure a successful food plot. The preparation, planting and available maintenance equipment will generally determine the plant species that can successfully be planted. Refer to MU Extension publication G4652, Seeding Rates, Dates and Depths for Common Missouri Forages, for more planting and agronomic recommendations for establishing forages that can be used for establishing food plots. Seeding can be done by drill, broadcast seeder or conventional planter, depending on the equipment that is available. A no-till drill is recommended when planting plants with larger seeds, such as corn and soybeans, or in rocky soil or sloped areas. No previous tillage is required when using a no-till drill. Whatever method you use, be sure to calibrate your seeder. Food plot maintenance For food plots to succeed and remain productive, they must be maintained and managed. Maintenance often includes controlling weeds, ensuring proper soil fertility and monitoring browse pressure. Control weeds Controlling competing vegetation is a recommended management practice. Grasses are generally not considered to be a preferred food for deer in the summer, so various grass-selective herbicides may need to be applied as a postemergence application in broad-leaved warm-season food plots. Cool-season forages, especially perennial plots that contain clover or alfalfa, are also vulnerable to broad-leaved annual weeds. Several preemergence herbicides are available for controlling winter annual weeds; however, adding oats or winter wheat to these mixtures may be beneficial, as they tend to germinate quickly and can help suppress weed growth to some extent. The appropriate herbicide depends on the food plot plants and the problem weed species. Follow all directions on the herbicide label and properly calibrate herbicide sprayers so the correct rates are applied to ensure success (Figure 11). Mowing or bush-hogging can also reduce broad-leaved weed competition. Food plots should be mowed before weeds flower and produce seeds. Mowing before a herbicide application can also help control weeds, particularly in mid-summer. Figure 11. Weeds may need to be controlled with herbicides to prevent them from competing with forages.   Manipulate the planting frequency Instead of replanting annuals in a food plot each year, either allow the entire area to go fallow for two to three years or alternately replant half the area and allow the other half to go fallow. Either practice will result in a diversity of vegetation and will provide nutritional forage for deer. Monitor food plot success The planting success and overall use of food plots should be monitored using exclusion cages. These cages allow you to see how much forage is being eaten — the “browse pressure” — over time and to assess use by deer. Exclusion cages prevent deer and other wildlife from feeding on plants in a small portion of the plot (Figure 12). The plants within the cages can be compared to those outside the cages to determine browsing pressure and planting success. The dimensions of these cages vary but generally need to be 4 feet high and 2 to 3 feet in diameter to provide useful comparisons. Figure 12. Exclosure cages are easy to construct out of 2-by-4-inch-mesh welded wire and a T-post, and provide a way to monitor browse pressure.   Conclusion The benefits of a food plot depend on management objectives and surrounding land-use practices. Although food plots can be beneficial, they will not resolve habitat problems, nor are they a replacement for habitat provided by native plant communities. However, properly managed food plots can provide supplemental food for deer during nutritional stress periods and can be an integral component of a deer management plan. A successful food plot program requires planning, dedication and a knowledge of farming practices. Food plots are a management practice that can be fairly expensive and labor-intensive to implement. There is no “magic mix” or gimmick that provides a quality year-round food source for wildlife. Rather, using food plots to provide supplemental nutrition for deer often requires multiple plantings in appropriate locations combined with effective management of habitat provided by native plant communities. Additional information Adams, A., and B. Burhans, eds. 2001. Get in the game: Attracting wild turkey and other wildlife to your land. Edgefield, SC: National Wild Turkey Federation. Harper, C.A. 2004. Growing and managing successful food plots for wildlife in the Mid-South (PB1743). Knoxville: University of Tennessee Agricultural Extension Service. Kammermeyer, K., K.V. Miller, and L. Thomas Jr. 2006. Quality food plots: Your guide to better deer and better deer hunting. Bogart, GA: Quality Deer Management Association.  Roberts, C., and J. Gerrish. 2001. Seeding rates, dates and depths for common Missouri forages (G4652). Columbia: University of Missouri Extension. Stewart, D. 2000. Wildlife food planting guide for the Southeast (Publication 2111). Mississippi State University Extension Service. Photo credits: Emily Flinn, Alex Foster, Robert Pierce, Ted Seiler, Joe McCray, Missouri Department of Conservation and University of Missouri Extension.

Electronic Work In Space   So in a basic sense, not much really changes, and it's possible, with a bit of work, to use off-the-shelf components to do the same job out in space. However, there's a subtler way in which earth-bound electronics do benefit from Earth's magnetic field. ... Electronics do not need a magnetic field to work .                                                               Challenges for Electronic Circuits in Space Applications  To set the stage for this discussion let me propose this scenario: imagine yourself as an astronaut sitting in the crew module of the NASA Orion spacecraft. You are stepping through your final equipment checklist for a voyage to Mars while sitting on top of a rocket, anticipating the final countdown to ignition of the largest rocket ever designed—the NASA Space Launch System. You are sitting 384 feet in the air on a massive, 130 metric ton configuration, the most capable and powerful launch vehicle in history. When you hear those famous words “gentlemen, we have ignition,” you will have 9.2 million pounds of thrust propelling you into outer space. The Orion spacecraft is being designed to take humans to Mars and into deep space where the temperature can approach over 2000°C, the radiation is deadly, and you will be travelling at speeds up to 20,000 mph.                                 Now , what quality grade of electronic components were selected for the control systems of your spacecraft? High reliability and devices with space heritage are key factors in the selection of components for space level applications. NASA generally specifies Level 1, qualified manufacturer list Class V (QMLV) devices, and they will always ask if there is a higher quality level available. Knowing the extensive selection process NASA uses for identifying electronic components for space flight applications, one should be confident sitting on top of that rocket. The Harsh Environmental Conditions of a Spacecraft and the Hazards Posed to the Electronics The first hurdle for space electronics to overcome is the vibration imposed by the launch vehicle. The demands placed on a rocket and its payload during launch are severe. Rocket launchers generate extreme noise and vibration. There are literally thousands of things that can go wrong and result in a ball of flame. When a satellite separates from the rocket in space, large shocks occur in the satellite’s body structure. Pyrotechnic shock is the dynamic structural shock that occurs when an explosion occurs on a structure. Pyroshock is the response of the structure to high frequency, high magnitude stress waves that propagate throughout the structure as a result of an explosive charge, like the ones used in a satellite ejection or the separation of two stages of a multistage rocket. Pyroshock exposure can damage circuit boards, short electrical components, or cause all sorts of other issues. Understanding the launch environment provides a greater appreciation for the shock and vibration requirements, and inspections imposed on electronic components designed for use in space level applications. Outgassing is another major concern. Plastics, glues, and adhesives can and do outgas. Vapor coming off of plastic devices can deposit material on optical devices, thereby degrading their performance. For instance, an automobile plastic dashboard can emit vapor that deposits a film on the windshield. This is a practical example I can attest to from personal experience. Using ceramic rather than plastic components eliminates this problem in electronics. Outgassing of volatile silicones in low Earth orbit (LEO) cause a cloud of contaminants around the spacecraft. Contamination from outgassing, venting, leaks, and thruster firing can degrade and modify the external surfaces of the spacecraft. High levels of contamination on surfaces can contribute to electrostatic discharge. Satellites are vulnerable to charging and discharging. For that reason, space applications require components with no floating metal. Satellite charging is a variation in the electrostatic potential of a satellite, with respect to the surrounding low density plasma around the satellite. The extent of the charging depends on the design of the satellite and the orbit. The two primary mechanisms responsible for charging are plasma bombardment and photoelectric effects. Discharges as high as 20,000 V have been known to occur on satellites in geosynchronous orbits. If protective design measures are not taken, electrostatic discharge, a buildup of energy from the space environment, can damage the devices. A design solution used in geosynchronous Earth orbit (GEO) is to coat all the outside surfaces of the satellite with a conducting material. The atmosphere in LEO is comprised of about 96% atomic oxygen. Oxygen exists in different forms. The oxygen that we breathe is O2. O3 occurs in Earth’s upper atmosphere, and O (one atom) is atomic oxygen. Atomic oxygen can react with organic materials on spacecraft exteriors and gradually damage them. Material erosion by atomic oxygen was noted on NASA’s first space shuttle missions, where the presence of atomic oxygen caused problems. Space shuttle materials looked frosty because they were actually being eroded and textured by the presence of atomic oxygen. NASA addressed this problem by developing a thin film coating that is immune to the reaction with atomic oxygen. Plastics are considerably sensitive to atomic oxygen and ionizing radiation. Coatings resistant to atomic oxygen are a common protection method for plastics. Another obstacle is the very high temperature fluctuations encountered by a spacecraft. A satellite orbiting around Earth can be divided into two phases; a sunlit phase and an eclipse phase. In the sunlit phase, the satellite is heated by the Sun and as the satellite moves around the back side or shadow side of the Earth, the temperature can change by as much as 300°C. Because it is closer to the Sun, the temperature fluctuations on a satellite in GEO stationary orbit will be much greater than the temperature variations on a satellite in LEO. It is interesting to note that during lunar day and night, the temperature on the surface of the Moon can vary from around –200°C to +200°C. It makes you wonder how it was even possible for a man to walk on the Moon. Here again, ceramic packages can withstand repeated temperature fluctuations, provide a greater level of hermeticity, and remain functional at higher power levels and temperatures. Ceramic packages provide higher reliability in harsh environments. So how do you dissipate the heat generated by the electronics? The accuracy and life expectancy of electronic devices can be degraded by sustained high temperatures. There are three ways of transferring heat: convective, diffusive, and radiative. In the vacuum of space there is no thermal convection or conduction taking place. Radiative heat transfer is the primary method of transferring heat in a vacuum, so satellites are cooled by radiating heat out into space. The vacuum of space is a favorable environment for tin whiskers, so prohibited materials are a concern. Pure tin, zinc, and cadmium plating are prohibited on IEEE parts and associated hardware in space. These materials are subject to the spontaneous growth of whiskers that can cause electrical shorts. Tin whiskers are electrically conductive, crystalline structures of tin that sometimes grow from surfaces where tin is used as a final finish. Devices with pure tin leads can suffer from the tin whiskers phenomenon that can cause electrical shorts. Using lead-based solder eliminates the risk of shorts occurring when devices are used in high stress applications. Finally, the space radiation environment can have damaging effects on spacecraft electronics. There are large variations in the levels of and types of radiation a spacecraft may encounter. Missions flying at low Earth orbits, highly elliptical orbits, geostationary orbits, and interplanetary missions have vastly different environments. In addition, those environments are changing. Radiation sources are affected by the activity of the Sun. The solar cycle is divided into two activity phases: the solar minimum and the solar maximum. Will your spacecraft mission occur during a solar minimum, a solar maximum period, or both? The key point here is that there are vastly different environments in space. The requirements for a launch vehicle are much different from that of a geostationary satellite or a Mars rover. Each space program has to be evaluated in terms of reliability, radiation tolerance, environmental stresses, the launch date, and the expected life cycle of the mission. Analog Devices has been supporting the aerospace and defense markets for over 40 years with high reliability devices. Areas of focus are electronic warfare, radar, communications, avionics, unmanned systems, and missile and smart munitions applications. Today’s focus is on the space market. Analog Devices has the depth and breadth of technologies that spans the complete signal chain from sensors, amplifiers, RF and microwave devices, ADCs, DACs, and output devices that provide solutions to the challenging requirements of the aerospace and defense industry.                               The satellite industry’s revenue was $208 billion in 2015. There are four segments to the satellite industry: satellite manufacturing, satellite launch equipment, ground-based equipment, and satellite services. Satellite services is by far the largest segment and continues to be a key driver for the overall satellite industry. So, what has a satellite done for you lately? I believe most people would be surprised at just how much modern life depends on satellites services. If the 1381 satellites currently in operation happen to shut down, modern life would be significantly disrupted. Global finance, telecommunications, transportation, weather, national defense, aviation, and many other sectors rely heavily on satellite services. There are three primary segments in the satellite services market: satellite navigation, satellite communications, and Earth observation. Navigation satellites are used for the global distribution of navigation signals and data in order to provide positioning, location, and timing services. Examples of available services are traffic management, surveying and mapping, fleet and asset management, and autonomous driving technology—driverless cars and trucks are expected to be the next big thing. Telecommunication satellites or SATCOM examples are television, telephone, broadband internet, and satellite radio. These systems can provide uninterrupted communications services in the event of disasters that damage ground-based telecommunication networks. Both business and commercial aircraft in-flight internet and mobile entertainment are growing segments of the market. Earth observation satellites are used for the transmission of environmental data. Space-based observations of the Earth promote sustainable agriculture and aid in the response to climate change, land and wildlife management, and energy resources management. Earth observation satellites aid in the safeguard of water resources and improve weather forecasts, so there is a very wide and growing range of satellite services. So what types of electronic systems are used on satellites? The basic elements of a spacecraft are divided into two sections: the platform or bus and the payload. The platform consists of the five basic subsystems that support the payload: the structural subsystem, the telemetry subsystem, tracking and command subsystems, the electric power and distribution subsystem, the thermal control subsystem, and the attitude and velocity control subsystem. The structural subsystem is the mechanical structure and provides stiffness to withstand stress and vibration. It also provides shielding from radiation for the electronic devices. The telemetry, tracking, and command subsystems include receivers, transmitters, antennas, sensors for temperature, current, voltage, and tank pressure. It also provides the status of various spacecraft subsystems. The electric power and distribution subsystems convert solar into electrical power and charge the spacecraft batteries. The thermal control subsystem helps to protect electronic equipment from extreme temperatures. And finally, the attitude and velocity control subsystem is the orbit control system that consists of sensors to measure vehicle orientation and actuators (reaction wheels, thrusters), and to apply the torques and forces needed to orient the vehicle in the correct orbital position. Typical components of the attitude and control system include Sun and Earth sensors, star sensors, momentum wheels, inertial measurement units (IMUs), and the electronics required to process the signals and control the satellites position. The payload is the equipment in support of the primary mission. For GPS navigation satellites, this would include atomic clocks, navigation signal generators, and high power RF amplifiers and antennas. For telecommunications systems, the payload would include antennas, transmitters and receivers, low noise amplifiers, mixers and local oscillators, demodulator and modulators, and power amplifiers. Earth observation payloads would include microwave and infrared sounding instruments for weather forecasting, visible infrared imaging radiometers, ozone mapping instruments, visible and infrared cameras, and sensors. The integration of Analog Devices and Hittite Microwave a few years ago now allows us to cover the dc to 110 GHz spectrum. ADI solutions range from navigation, radar, communication systems below 6 GHz, satellite communications, electronic warfare, radar systems in the microwave spectrum, radar systems, and satellite imaging in the millimeter wave spectrum. Analog Devices offers more than 1000 components covering all RF and microwave signal chains and applications. The combination of Hittite’s full spectrum of RF function blocks, attenuators, LNAs, PAs, and RF switches, in conjunction with Analog Devices portfolio of high performance linear products, high speed ADCs, DACs, active mixers, and PLLs can provide end-to-end system solutions. The Natural Space Radiation Environment Effects on Electronic Devices The radiation effects on electronic devices are a primary concern for space level applications. Outside the protective cover of the Earth’s atmosphere, the solar system is filled with radiation. The natural space radiation environment can damage electronic devices and the effects range from a degradation in parametric performance to a complete functional failure. These effects can result in reduced mission lifetimes and major satellite system failures. The radiation environment close to Earth is divided into two categories: particles trapped in the Van Allen belts and transient radiation. The particles trapped in the Van Allen belts are composed of energetic protons, electrons, and heavy ions. The transient radiation consists of galactic cosmic ray particles and particles from solar events (coronal mass ejections and solar flares). There are two primary ways that radiation can effect satellite electronics: total ionizing dose (TID) and single event effects (SEEs). TID is a long-term failure mechanism vs. SEE, which is an instantaneous failure mechanism. SEE is expressed in terms of a random failure rate, whereas TID is a failure rate that can be described by a mean time to failure.                                                       Sources of ionizing radiation in interplanetary space TID is a time dependent, accumulated charge in a device over the lifetime of a mission. A particle passing through a transistor generates electron hole pairs in the thermal oxide. The accumulated charges can create leakage currents, degrade the gain of a device, affect timing characteristics, and, in some cases, result in complete functional failure. The total accumulated dose depends on the orbit and time. In LEO, the main source of radiation is from electrons and protons (inner belt) and in GEO, the primary source is from electrons (outer belt) and solar protons. It is worth noting that device shielding can be used to effectively reduce the accumulation of TID radiation. SEEs are caused by a single, high energy particle passing through a device and injecting a charge in the circuit. Typically, SEEs are divided into soft errors and hard errors. The Joint Electron Device Engineering Council (JEDEC) defines soft errors as nondestructive, functional errors induced by energetic ion strikes. Soft errors are a subset of SEEs and includes single event upsets (SEUs), multiple-bit upsets (MBUs), single event functional interrupts (SEFIs), single event transients (SETs), and single event latch-up (SEL). A SEL is where the formation of parasitic bipolar action in CMOS wells induces a low impedance path between power and ground, producing a high current condition. Therefore, a SEL can cause latent and hard errors. Examples of soft errors would be bit flips or changes in the state of memory cells or registers. A SET is a transient voltage pulse generated by a charge injected into the device from a high energy particle. These transient pulses can cause SEFIs. SEFIs are soft errors that cause the component to reset, lock-up, or otherwise malfunction in a detectable way, but does not require power cycling of the device to restore operability. A SEFI is often associated with an upset in a control bit or register. JEDEC defines a hard error as an irreversible change in operation that is typically associated with permanent damage to one or more elements of a device or circuit (for example, gate oxide rupture, or destructive latch-up events). The error is hard because the data is lost and the component or device no longer functions properly, even with a power reset. SEE hard errors are potentially destructive. Examples of hard errors are single event latch-up (SEL), single event gate rupture (SEGR), and single event burnout (SEB). SEEs hard errors can destroy the device, drag down the bus voltage, or even damage the system power supply. Technology Trends and Radiation Effects In terms of the satellite payload, instruments are becoming more complex. At one time communication satellites were basically bent pipe repeater architectures that would relay signals. Today they are multibeam and have on-board processing (OBP) architectures. More complex electronics translate into greater risk from radiation effects. High volume, small satellite constellations are using more commercial grade plastic components. Commercial off-the-shelf (COTS) devices generally tend to be more sensitive to radiation effects. Also with small satellite, there is less structural mass shielding the electronics. With finer IC geometries and thinner oxides, the sensitivity to TID radiation effects is reduced, and the TID tolerance is improved. On the other hand, SEEs increase with reduced IC scaling. Less energy is required to produce SET and SEU. With higher frequency devices, SETs can turn into more SEUs, increasing the number of SEFIs. Mitigation techniques used to address higher speed transient signals can be more challenging. Analog Devices’ Efforts in Support of Space Level Applications The space products group leverages Analog Devices’ portfolio of devices in the support of the space industry. We have proprietary silicon on insulator (SOI) processes that provide radiation tolerance for space level applications. In some cases we modify core silicon to enhance the radiation tolerance of devices. We also have the ability to port designs over to radiation hardened SOI processes. We integrate the die into hermetic, ceramic packages and characterize the device over the extended military temperature range. We target the development and release of fully qualified, Class S QMLV products using the defense logistics agency (DLA) MIL-PRF 38535 system for monolithic devices, and MIL-PRF 38534 for Class K hybrid and multichip modules. For radiation inspection we currently offer high dose rate (HDR) and low dose rate (LDR) tested models and for new product releases we offer single event effects test data. Analog Devices offers commercial, industrial, enhance products (EPs), automotive, military, and space qualified devices. EP devices are designed to meet mission critical and high reliability applications, primarily in the aerospace and defence market. Other product grades include military grade monolithic devices, multichip modules, QMLQ and QMLH devices, space qualified monolithic devices, and multichip modules designed under military specifications as QMLV and QMLK devices. Analog Devices also offers space qualified Class K die for customers who are developing hybrid or multichip modules solutions. Class K qualified die are offered against standard aerospace data sheets and customer source control drawings. We offer EPs, plastic encapsulated devices designed to meet mission critical requirements, and high reliability application requirements. With customer input, we are initiating a new device product category for space applications that we have defined as enhanced products plus (EP+) devices. Our customers are requiring improvements in size, weight, power, higher performance, wider bandwidths, increased operational frequencies, payload flexibility, and optimized reliability. Spacecraft designers are being pressed to use commercial devices in order to meet high levels of performance in increasingly smaller, lower power, and lower cost spacecraft. The internet in the sky is a good example. It is estimated that 60% of the world’s population does not have access to the internet. To address this market, companies are planning to deploy large constellations of small, low cost satellites circling the Earth that will enable access to a worldwide communication network. Analog Devices is working with customers to define EP+ to address this evolving new market. EPs provide COTS solutions for high reliability applications with no additional cost of custom upscreening. EPs are plastic encapsulated devices released with a military temperature range of –55°C to +125°C. In addition to requiring an extended temperature range, EP customers require devices to be lead free and whisker free. They require devices with a controlled manufacturing baseline, a standalone data sheet, and an EP change notification process. These devices also have an associated V62 vendor item drawing under the defense logistics agency documentation system. Currently released EPs are identified by a special EP suffix and have a separate standalone data sheet. As noted, Analog Devices is also developing a new device concept for space level applications EPs, plus for LEO systems and high altitude applications. We currently support EP+ against source control drawings. ADI would like to offer a standard COTS grade device for space level applications. With the EP+ approach we envision a device somewhere between standard EP devices and military 883-grade devices, providing COTS solutions for space level applications without additional cost of custom upscreening. With the EP+ approach, we can generate COTS devices and provide wafer lot traceability and lot specific radiation inspection data. The key issue is determining the proper balance between reliability and cost as depicted in the curve in Figure 1. The more screening required, the higher the unit cost. In defining this new product category, the current challenge for the satellite industry and for Analog Devices is to define the optimum screening level vs. cost point for commercial devices used in space level applications. Figure 1. Reliability test and inspections drive electronic component cost. To summarize—Analog Devices’ goal is to deliver a complete product for space level applications and not just a component. We offer the industry’s most comprehensive portfolio with industry-leading device reliability We provide single lot date code procurement Advanced packaging and characterization to meet harsh environmental challenges Gold and tin lead hot solder dip lead finishes to address tin whiskers We provide no prohibited materials certification Comprehensive certificates of conformance with material traceability Comprehensive QMLV flight unit test reports Electrical performance is production tested over the extended temperature ranges –55°C to +125°C We offer fully qualified QMLV devices with 100% screening and quality conformance inspection We provide radiation qualified devices … HDR, LDR, SEE Long product life cycles are a cornerstone of ADI’s business strategy We have a dedicated aerospace and defense team for product support and applications support Analog Devices currently offers over 90 standard generic space qualified devices with greater than 350 models in different grades and packages. A few of the new featured space qualified products are the ADA4084-2S, ADA4610-2S, and ADuM7442S devices. The 5962R1324501VXA (ADA4084AF/QMLR) is a new low noise, low power, space qualified precision amplifier offered as QMLV space qualified device available against a SMD drawing. The device has 10 MHz unity-gain bandwidth and rail-to-rail inputs and outputs. These amplifiers are excellent for single-supply applications requiring both ac and precision dc performance. The 5962R1420701VXA (ADA4610-2BF/QMLR) are space qualified, dual-channel, precision, very low noise, low input bias current wide bandwidth JFET devices. The amplifiers are especially suited for high impedance sensor amplification and precise current measurements. The ADuM7442R703F is a space qualified 25 Mbps, quad-channel digital isolator with three forward and one reverse channel. The devices offer bidirectional communications. The space qualified devices offer galvanic isolation, which means that the input and output circuits have no direct electrical connection. They offer advantages in size, weight, power, and reliability over competing solutions.                             Analog and Digital Circuits Analog Electronics Most of the fundamental electronic components -- resistors, capacitors, inductors, diodes, transistors, and operational amplifiers -- are all inherently analog. Circuits built with a combination of solely these components are usually analog. Analog circuits are usually complex combinations of op amps, resistors, caps, and other foundational electronic components. This is an example of a class B analog audio amplifier. Analog circuits can be very elegant designs with many components, or they can be very simple, like two resistors combining to make a voltage divider. In general, though, analog circuits are much more difficult to design than those which accomplish the same task digitally. It takes a special kind of analog circuit wizard to design an analog radio receiver, or an analog battery charger; digital components exist to make those designs much simpler. Analog circuits are usually much more susceptible to noise (small, undesired variations in voltage). Small changes in the voltage level of an analog signal may produce significant errors when being processed. Digital Electronics Digital circuits operate using digital, discrete signals. These circuits are usually made of a combination of transistors and logic gates and, at higher levels, microcontrollers or other computing chips. Most processors, whether they're big beefy processors in your computer, or tiny little microcontrollers, operate in the digital realm. Digital circuits make use of components like logic gates, or more complicated digital ICs (usually represented by rectangles with labeled pins extending from them). Digital circuits usually use a binary scheme for digital signaling. These systems assign two different voltages as two different logic levels -- a high voltage (usually 5V, 3.3V, or 1.8V) represents one value and a low voltage (usually 0V) represents the other. Although digital circuits are generally easier to design, they do tend to be a bit more expensive than an equally tasked analog circuit. Analog and Digital Combined It's not rare to see a mixture of analog and digital components in a circuit. Although microcontrollers are usually digital beasts, they often have internal circuitry which enables them to interface with analog circuitry (analog-to-digital converters, pulse-width modulation, and digital-to-analog converters. An analog-to-digital converter (ADC) allows a microcontroller to connect to an analog sensor (like photocells or temperature sensors), to read in an analog voltage. The less common digital-to-analog converter allows a microcontroller to produce analog voltages, which is handy when it needs to make sound.                            Resources and Going Further Now that you know the difference between analog and digital signals, we'd suggest checking out the Analog to Digital Conversion tutorial. Working with microcontrollers, or really any logic-based electronics, means working in the digital realm most of the time. If you want to sense light, temperature, or interface a microcontroller with a variety of other analog sensors, you'll need to know how to convert the analog voltage they produce into a digital value. Also, consider reading our Pulse Width Modulation (PWM) tutorial. PWM is a trick microcontrollers can use to make a digital signal appear to be analog. Here are some other subjects which deal heavily with digital interfaces: Binary Logic Levels Serial Communication SPI Communication I2C Communication IR Communication Or, if you'd like to delve further into the analog realm, consider checking out subject : Voltage Dividers Resistors Diodes Capacitors Transistors                 electronic reliability in space Components for new space systems must still meet requirements for radiation tolerance and electrical, thermal, and mechanical reliability. However, a new class of space-plastic–grade ICs can provide cost and size benefits compared to traditional “full space” components for lower-altitude missions. For the next 40-plus years, the consequences of losing any spacecraft to electronics failure were generally catastrophic. It goes without saying that manned space missions have always carried the highest priority for safety to protect their priceless passengers. But the costs of building unmanned satellites soared into the hundreds of millions of dollars, even exceeding the billion-dollar level for advanced government satellite programs. Satellites became critical to many facets of everyday life: for television viewing, weather forecasting, navigation, and, of course, military uses. The cost of launching was so high that only a few countries could afford the endeavor. With such astronomical (pun intended) consequences of failure, government spaceflight organizations and spacecraft manufacturers created requirements and standards to ensure the robustness of electronic components in space. You may hear spacecraft engineers refer to such components as triple-E parts, which is shorthand for electrical, electronic, and electromechanical components. Manufacturers typically implemented specifications by creating device-specific source control drawings (SCDs), which focused on testing integrated circuits (ICs) for radiation performance, operating life, thermal performance, and mechanical resistance to forces endured during launch. A common mission profile for SCDs was based on 15 years of operation in geosynchronous Earth orbit (GEO), approximately 36,000 km above Earth. That’s quite a change from those first rockets, which flew just above 100 km for only a few minutes! Mil standards By 1995, the U.S. government (namely, the Department of Defense) had released the MIL-PRF-38535 standard, which created consistent qualification, testing, and reliability standards for military and space ICs. MIL-PRF-38535 defines requirements for IC manufacturers if they wish to be listed on a qualified manufacturer list (QML), along with requirements for ICs to qualify to specific classes. Classes M, N, and Q are intended for terrestrial applications, while Class V is defined for space applications, requiring hermetically sealed packaging. Class V devices are typically tested for radiation tolerance during development and are not radiation-tested in production. MIL-PRF-38535 defines an additional quality level — radiation hardness assured (RHA) — that requires the screening of each production lot of an IC to meet a specified radiation performance level (more on radiation performance in a minute). Radiation-tolerant ICs that meet QML Class V requirements are often referred to as QMLV devices, while devices that also meet the RHA specifications are called QMLV-RHA or, simply, RHA. In 2012, MIL-PRF-38535 was revised to add a Class Y, covering non-hermetically sealed, high-pin-count land-grid-array– and column-grid-array–packaged devices. Since the creation of the QMLV designation, designers of high-value, mission-critical spacecraft have come to rely on QMLV and RHA ICs to ensure mission success. The high level of quality and reliability of these components results in a higher cost, but in the intended application, the cost can be justified due to the level of risk mitigation needed. Cost factors In recent years, changes in a number of factors have combined to reduce the cost of access to space. Both scientific and commercial organizations have shown that lower-cost small satellites (smallsats) can also be of value alongside the traditional “big birds” deployed for long-life missions. Smallsats in low Earth orbit (LEO) have provided useful data on a variety of scientific Earth observation missions, with mission lives as short as a week. It is now possible for researchers, entrepreneurs, and students to get a smallsat into LEO at a relatively low cost. Commercial launch operators also offer “ride-sharing” for smallsats on launches in which the primary mission is for a larger satellite. NASA and its commercial partners deliver smallsats to the International Space Station (ISS) aboard re-supply missions, wherein the satellites are then deployed into space by astronauts living onboard the ISS. This new array of satellite missions has given rise to a much wider variation in risk tolerance and cost sensitivity compared to traditional missions. Engineers designing smallsats for LEO missions with shorter mission durations and lower-cost targets have begun to use commercial-off-the-shelf (COTS) ICs, which receive no special screening from manufacturers to address the hazards of spaceflight. These COTS ICs are encapsulated in plastic packaging, which reduces their size compared to the hermetically sealed ceramic packages of space-grade components, and have electrical performance benefits. However, the use of COTS components can expose a mission to significant risks, and selecting, screening, and testing ICs to mitigate these risks can end up costing many times more than the ICs themselves. Another term used to refer to plastic-packaged ICs used in space is plastic encapsulated microcircuits (PEMs). PEMs may be COTS or specially screened or tested. There has also been interest in using automotive-qualified, or AEC-Q100 (“Q1” for short), grade parts in space. While these devices receive additional testing and qualification compared to commercial ICs, these tests are focused more on the terrestrial environment than the extreme environment of space. The use of COTS and Q1 ICs can also require compromises in system design and operational readiness when the radiation hardness and other reliability factors of the components are not well-controlled. Due to the desire for ICs to deliver the necessary quality and reliability for shorter, lower-altitude missions at a lower cost point compared to QMLV devices, a number of IC suppliers have introduced new grades of IC, which fit between COTS and space grade (QMLV) from a cost perspective. These “new space” or “space plastic” ICs use plastic packaging but undergo significant additional testing and qualification compared to COTS and Q1 devices. Fig. 1compares COTS and Q1 ICs to high-reliability parts. Fig. 1: Comparison of different reliability grades from Texas Instruments. Next, We’ll discuss the risks of COTS and Q1 ICs in space and how the enhanced quality and reliability of space plastic ICs can enable success for shorter LEO smallsat missions. Radiation The tragic story of Telsat underscored the need to address radiation performance in space-borne electronics. If you don’t have (or plan to get) a Ph.D. in nuclear physics, you can use a couple of analogies to understand radiation effects on electronics. I’ll categorize effects into two primary categories: total dose effects and single-event effects (SEEs). Consider total dose effects analogous to sunburn: The longer a spacecraft is in space and the farther it is from Earth, the higher the total dose received and the resulting sunburn. Engineers quantify radiation effects like this as total ionizing dose (TID), measured in units of kilorads (krad). SEEs are more like a lightning strike: The probability of an occurrence at any moment is low, but the longer a spacecraft is out in the “thunderstorm” of space, the more likely it is to be struck by a highly energetic particle that can cause failure. The sensitivity of an electronic component to SEEs is measured as a quantity called linear energy transfer, which is the energy transferred from a particle to a substance measured in units of MeV∙cm2/mg. A particular type of SEE that designers are particularly concerned with is single-event latchup (SEL), which is a high-current condition that can destroy an IC quickly. We can “thank our lucky stars” that Earth’s magnetic field protects our earthbound electronics and delicate bodies from the harsh radiation environment of space. Traditional space-grade (QMLV and RHA) ICs have been designed, qualified, and tested to meet all specifications to TID levels as high as 1 Megarad (Mrad). For the sake of comparison, an unshielded satellite in GEO could absorb a TID of over 20 Mrad in just one year. In practice, shielding satellites can drastically reduce the dosage, but long-life GEO missions typically look for ICs with ratings of at least 100 krad. In contrast, the same unshielded satellite in LEO would absorb only about 100 krad in a year. While smallsats in LEO cannot typically support heavy shielding, the shorter mission profiles mean that TID requirements of 10–30 krad are often sufficient for these applications. Beyond defining the necessary radiation tolerance level, there are two primary challenges when trying to use a COTS IC for spaceflight: measuring the device’s radiation tolerance and potential variation in that tolerance. Testing ICs for radiation tolerance can be an expensive and time-consuming process due to the specialized radiation test equipment required. For SEE testing, there are only two cyclotrons in the entire U.S. with the heavy-ion beam capability to test devices for spaceflight cost-effectively. Sometimes, engineers can find radiation test data from academic studies or third-party testing. Such test data may be less accurate than testing by an IC manufacturer. Plus, researchers and third parties typically don’t have access to hidden test modes and may not fully understand the proper operation, specifications, and testing of the device. Second, the lot-to-lot variation of the radiation tolerance of an IC can be huge. It has been shown numerous times that the radiation performance of a particular IC can vary greatly from one wafer fabrication lot to another. Today’s high-volume semiconductor wafer fabs are great at controlling electrical parameters but do not control for radiation performance. For example, National Semiconductor’s space-grade LM108 operational amplifier could produce a lot rated to 100 krad one month and have another lot fail at 30 krad the next month. For this reason, radiation lot acceptance testing (RLAT) has been a fundamental pillar of manufacturing ICs for space since the days of SCDs. COTS ICs, even within a single reel, can come from different wafer lots, even different wafer fab factories, yielding drastic swings in radiation tolerance. Flexibility in wafer supply is a benefit for commercial applications but a risk for space missions. Space-plastic–grade components will go through at least one-time radiation testing by the manufacturer to ensure the validity of the radiation performance and eliminate ICs unsuitable for spaceflight. The TID specification varies by manufacturer but typically targets a TID of 30 krad and single-event latchup immunity to 40 MeV∙cm2/mg, in line with radiation levels within LEO. Texas Instruments’ space-enhanced product line goes the extra mile by undergoing RLAT to 20-krad TID in every production lot, in addition to a one-time characterization to 30 krad. In addition, space plastic products are manufactured within a single controlled baseline, which means one wafer fab, one assembly site, and one material set, and greatly reduces sources of variability. Mechanical and thermal concerns In the extreme environment of space, electronic systems are subjected to extreme temperatures and associated thermal cycles, which cause mechanical stress on ICs and their packages. In LEO, satellites orbit the earth at least 12 times a day, passing from the extreme heat of direct sunlight to the extreme cold of darkness in space. This can result in thermal gradients of over 3°C (5.5°F) per minute, even inside the relatively temperature-controlled internal volume of a spacecraft. Components can be subjected to temperatures as low as –55°C (–67°F) and as high as 125°C (257°F). These thermal conditions can induce a number of different failure modes, including package and die cracking, bond-wire breakage, moisture ingress, die delamination, tin whisker growth, and solder-joint failure. Low-cost packaging materials used in COTS components are susceptible to all of these failures, while space plastic ICs utilize enhanced-reliability material sets and undergo specialized testing to ensure robustness. Because of the reliability concerns associated with lead (Pb)-free solder, the military and aerospace industries have been allowed to continue using tin-lead (SnPb) solder. When a typical commercial Pb-free solder ball is combined with SnPb solder, reflow temperature mismatch and insufficient mixing of the two types of solder can create voiding and a solder joint too fragile to withstand board- and system-level temperature cycling and vibration. For ball-grid-array (BGA) packages in space-plastic–grade ICs, SnPb solder balls are used to eliminate the risk of incompatibility within the SnPb solder profile. Typical commercial ICs are tested only under thermal/moisture testing such as temperature cycling and highly accelerated stress testing (HAST) at the time of development, whereas space plastic ICs typically undergo temperature cycle and HAST lot acceptance continuously throughout production. This practice ensures that any anomalies in package performance can be contained before reaching the customer. It is possible to select packaging materials like die attach epoxy, mold compound, leadframe, and bond wire for robustness. Typically, formulations of die attach and mold compounds are proprietary to the manufacturer, but there are clear variations across the industry. Space plastic IC makers should select the highest-performing compounds regardless of cost. A failure mode of particular concern in harsh environments is delamination, wherein the silicon die separates from the package leadframe, and can lead to performance degradation or, in extreme cases, all-out failure of the die. IC package leadframes can have varying performance with respect to cracking and die delamination. One well-studied technique to improve resistance to die delamination is roughening. This increases the adhesion of the die to the leadframe in conjunction with the correct die attach compound. Roughening adds cost to leadframe manufacturing and, therefore, is not commonly used in the manufacturing of COTS ICs, but it is standard practice for space plastic ICs. Bond wires can also be a source of failure for ICs in spaceflight. While copper (Cu) bond wire is well-proven in multiple terrestrial applications, and ongoing process improvements have resulted in increased uniformity and improved overall field defect parts per million, spacecraft manufacturers and government organizations still have concerns about the use of Cu wire in space components. A few key issues identified with Cu wire bonds are: Bond integrity issues with Cu wire bonding to aluminum bond pads Corrosion due to mold compound interaction or moisture ingress Bond-wire neck breaks due to coefficient of thermal expansion mismatch during temperature cycling While many COTS ICs are manufactured with low-cost Cu wire, space plastic components are manufactured with gold wire, which has been proven in high-reliability applications. Tin (Sn) whisker growth is a widely studied phenomenon in the aerospace industry and can be observed in ICs in leaded packages that have an Sn-based lead finish. Space plastic IC makers ensure that matte-Sn and other high-Sn content lead finishes are not used on such components. For BGA packages, many commercial IC manufacturers moved to high-Sn content solder in order to eliminate Pb-based solder balls, which is a government requirement for commercial applications. Outgassing Outgassing is the release of gas from any material and has been demonstrated in numerous mold compounds used in plastic IC packaging. While this phenomenon has not typically been an issue for terrestrial applications, it can be of particular concern in space. The vacuum environment of space can increase the amount of outgassing compared to atmospheric conditions on Earth. Furthermore, in spacecraft, gases released from IC packages and other sources can condense during extreme cold, creating reduced image quality on optical sensors or other moisture-related failures. NASA began testing materials for outgassing in 1967 and developed the American Society for Testing and Materials E595 specification, which requires that collected volatile condensable materials are less than 0.1% and the total mass loss is less than 1% after vacuum testing. In order to eliminate risk from outgassing in space applications, space plastic ICs use low-outgassing mold compounds that meet NASA requirements. Summary Efforts to ensure the quality and reliability of electronics in spacecraft have continued to evolve since the initial failure of Telstar. The evolution of the spaceflight industry has recently created an opportunity to use electronic components without the full testing and qualification of traditional QMLV components. However, components for these new space systems must still meet mission requirements for radiation tolerance and electrical, thermal, and mechanical reliability. The new class of space-plastic–grade ICs can provide cost and size benefits compared to traditional “full space” components while still contributing to the success of shorter, lower-altitude missions. Space Is Opening Up for Electronics Design This Special Project on Space Electronics seeks to help make the opportunities in space electronics more accessible by introducing these technologies and design experiences. It starts by discussing the trends and opportunities from this new era in space electronics. It then goes on to provide insights into the design challenges, best practices, tools, and components of electronics design for a space environment. A new era in Space Electronics The development of reusable rockets is lowering barriers to both scientific and commercial exploration of space, stimulating increasing interest and investment in space electronics. This Special Project provides designers with a look at the technologies and design practices needed for creating space-worthy electronic designs. These may include, but not be limited to ICs, ASICs, flex-cable, connectors, thermal management for electronics, Rad hard techniques, space-related testing methods, Apollo 1960s electronics and more. EMC in space: The James Webb space telescope Testing for EMC on a spacecraft isn't unlike testing for terrestrial equipment, except for the fact that spacecrafts live in a different electromagnetic environment. The convergence of traditional and new space electronics solutions A hybrid approach allows a design team to implement a rad-hard functional base in conjunction with the latest state-of-the-art COTS technologies. AI and Machine Learning: Shaking up the space industry Today’s increasingly ambitious mission requirements are demanding higher levels of autonomy and greater navigational precision from spacecraft, requiring more than logic-based AI. High-precision space navigation to small comets and asteroids; entry, descent and landing (EDL) on moons and planets; and, rendezvous and proximity operations (RPO) with both cooperative and uncooperative targets all need sensing and perception capabilities provided by vision-based systems. Changing trends in designing space electronics Space electronics has moved-on considerably from the bespoke, radiation-hardened guidance computer and hand-woven memories used on the Apollo missions. Today's avionics are millions of times more powerful than that used to land man on the moon! Safe and Affordable Space Travel Starts With Sourcing Commercial space tourism is on the rise, at a fraction of its predecessor’s cost, creating a cause for passenger safety concerns. One crucial aspect of space flight safety is radiation shielding and mitigation, which New Space ventures have not thoroughly addressed in the past. Traditional space radiation mitigation strategies are costly, yet New Space mitigation techniques may not be suitable for safety critical missions. A solution to this cost-safety tradeoff is Sub-QML hardware electronic devices, which are radiation-hardened by design, yet available at a lower price point due to reduced screening levels. Mission Critical Space Flight Systems Stay Rad Hard To understand the effects of radiation on electronic systems and components, we explore the effects of various space radiation environments and their impact on commercial “New Space” Decrease time to market and cost for the newspace market by using radiation-tolerant solutions based on COTS devices ATmegaS64M1 MCU allows customers to begin development with a commercial device before moving to a pinout compatible, qualified radiation-tolerant version                              Developing radiation-hardened systems for space applications has a history of long lead times and high costs to achieve the highest level of reliability for multi-year missions in a harsh environment.  NewSpace and other critical aerospace applications require faster development and reduced costs. To meet these needs, a new microcontroller (MCU) that combines specified radiation performance with low-cost development associated with Commercial Off-The-Shelf (COTS) devices is now available from Microchip Technology Inc. (NASDAQ: MCHP). The ATmegaS64M1 is the second 8-bit megaAVR® MCU from Microchip that uses a development approach called COTS-to-radiation-tolerant. This approach takes a proven automotive-qualified device, the ATmega64M1 in this case, and creates pinout compatible versions in both high-reliability plastic and space-grade ceramic packages. The devices are designed to meet radiation tolerances with the following targeted performances: Fully immune from Single-Event Latchup (SEL) up to 62 MeV.cm²/mg No Single-Event Functional Interrupts (SEFI) which secure memory integrity Accumulated Total Ionizing Dose (TID) between 20 to 50 Krad(Si) Single Event Upset (SEU) characterization for all functional blocks The new device joins the ATmegaS128, a radiation-tolerant MCU that has already been designed into several critical space missions including a Mars exploration plus a megaconstellation of several hundred Low Earth Orbit (LEO) satellites. The ATmega64M1 COTS device, along with its full development toolchain including development kits and code configurator, can be used to begin development of hardware, firmware and software. When the final system is ready for the prototype phase or production, the COTS device can be replaced with a pin-out compatible, radiation-tolerant version in a 32-lead ceramic package (QFP32) with the same functionality as the original device. This leads to significant cost savings while also reducing development time and risk. “Our COTS-to-radiation-tolerant approach results in a no-compromise, space-grade component and not merely an up-screened or enhanced device that’s targeted to the aerospace industry,” said Patrick Sauvage, director of Microchip’s aerospace business unit. “Developing with a COTS device that can be swapped out for a fully functional high-rel plastic or ceramic equivalent with the same pinout reduces development time, costs and risk for our customers.” The ATmegaS64M1 meets the high operating temperature range of -55° C to +125° C. It is the first COTS-to-radiation-tolerant MCU to combine a Controller Area Network (CAN) bus, Digital-to-Analog Converter (DAC) and motor control capabilities. These features make it ideal for a variety of subsystems like remote terminal controllers and data handling functions for satellites, constellations, launchers or critical avionic applications. For more information visit www.microchip.com/ATmegaS64M1. Development Support To ease the design process and accelerate time to market, Microchip offers the STK 600 complete development board for the ATmegaS64M1, giving designers a quick start to develop code with advanced features for prototyping and testing new designs. The device is supported by Atmel Studio Integrated Development Environment (IDE) for developing, debugging and software libraries. Availability and Packaging The devices are available today for sampling and volume production in four derivatives: ATmegaS64M1-KH-E in ceramic prototype QFP32 package ATmegaS64M1-KH-MQ, ceramic space-grade QFP32 package, QMLQ qualified ATmegaS64M1-KH-SV, ceramic space-grade QFP32 package, QMLV qualified  ATmegaS64M1-MD-HP in plastic QFP32 package, AQEC high reliability qualified for volume program .          COTS Arm Core MCUs deliver quick prototyping for space applications Microchip’s COTS-to-radiation–tolerant and radiation-hardened Arm Core MCUs enable designers to start prototyping faster and at a lower cost . Microchip Technology Inc. has launched the space industry’s first Arm-based microcontrollers (MCUs) that combine the benefits of commercial off-the-shelf (COTS) technology with space-qualified versions that have scalable levels of radiation performance. This allows designers to start prototyping with a commercial device before moving to a radiation-qualified version, which cuts development time and cost. The new SAMV71Q21RT radiation-tolerant and SAMRH71 radiation-hardened MCUs are based on the automotive-qualified SAMV71 and implement the Arm Cortex-M7 system-on-chip (SoC). This enables more integration, cost reduction, and higher performance in space systems, said Microchip. Software developers can start their designs with a lower-cost COTS SAMV71 device before moving to a space-grade component. Both COTS devices use the same software development toolchain, including software libraries, board support package (BSP), and operating system (OS) first level of porting. All software development can be swapped out to a radiation-tolerant or radiation-hardened version in a high-reliability plastic package or space-grade ceramic package. Microchip said that the SAMV71Q21RT radiation-tolerant MCU reuses the full COTS mask set and offers pinout compatibility, so designers can quickly scale from COTS to qualified space parts.              The SAMV71Q21RT can be used in NewSpace applications such as low earth orbit (LEO) satellite constellations and robotics. The SAMV71Q21RT ensures an accumulated TID of 30 Krad (Si) with latchup immunity and is nondestructive against heavy ions. The SAMRH71 radiation-hardened MCU is designed for more critical sub-systems like gyroscopes and star tracker equipment and deep-space applications. It also features dedicated SpaceWire and MIL-STD-1553 interfaces for control and high-speed data management up to 200 Mbits/s. Radiation performance includes: Accumulated TID of more than 100 Krad (Si) No Single Event Upset (SEU) Linear Energy Transfer (LET) up to 20 MeV.cm²/mg, without system mitigation Designed for No Single-Event Functional Interrupts (SEFI), which secures all memories’ integrity Both devices are fully immune to Single-Event Latchup (SEL) up to 62 MeV.cm²/mg. Other key features include fault management and data integrity features such as error-correcting code (ECC) memory, integrity check monitor (ICM), and memory protection unit (MPU), as well as CAN FD and Ethernet AVB/TSN connectivity. An evaluation board (ATSAMV71-XULT) is available. Designers can use the Atmel Studio Integrated Development Environment (IDE) for developing, debugging, and software libraries. Both devices will also be supported in MPLAB Harmony version 3.0 by mid-2019. Sampling is available for the SAMRH71 in a CQFP256 ceramic package, while the SAMV71Q21RT is available in volume-production quantities in four derivatives: SAMV71Q21RT-DHB-E in ceramic prototype QFP144 package  SAMV71Q21RT-DHB-MQ in ceramic space-grade QFP144 package, QMLQ equivalent SAMV71Q21RT-DHB-SV in ceramic space-grade QFP144 package, QMLV equivalent SAMV71Q21RT-DHB-MQ in plastic QFP144 package, AQEC high reliability qualified Intersil’s new radiation-tolerant plastic ICs to power                                     Small satellite mega-constellations Intersil, a subsidiary of Renesas Electronics Corporation (TSE: 6723), announced the first three members of its new family of radiation-tolerant plastic-package ICs designed to support the emerging field of small satellites that will provide solutions such as high-speed Internet connections to hundreds of millions of users in communities, governments, and businesses worldwide. Fleets of hundreds of small satellites will create mega-constellation networks to deliver broadband Internet links from low Earth orbit (LEO) to every corner of the globe, including rural areas without wireless connectivity access. Intersil’s rad-tolerant plastic parts include the ISL71026M 3.3V controller area network (CAN) transceiver, ISL71444M 40V quad precision rail-to-rail input and output (RRIO) op amp, and the ISL71001M 6A point-of-load (POL) voltage regulator. These ICs deliver rad-tolerance performance at a much lower cost point versus radiation assurance tested Class V (space level) products. All three ISL71xxxM devices go through characterization testing, which includes total ionizing doze (TID) up to 30krads (Si) for single event effects (SEE). SEE take into account single event burnout (SEB), single event latch-up (SEL), single event transients (SETs) and single event functional interrupts (SEFIs) at a linear energy transfer (LET) of 43MeV•cm2/mg. Intersil’s rad-tolerant plastic packaging flow leverages the company’s more than 50 years of spaceflight experience developing rad hard (>75krad) and rad-tolerant (<75krad) products for extremely harsh environments. The upfront radiation effects characterization and AEC-Q100 automotive-like qualification gives customers the utmost confidence to design Intersil radiation-tolerant plastic parts into cost-sensitive small satellites for LEO mission profiles up to five-years. The ISL71xxxM are also well suited for high altitude (>40km) avionic systems, launch vehicles that are prone to heavy ions, and medical equipment where radiation is a concern. “The short mission life of small satellites and less stringent low earth orbit is driving the trend toward low-cost commercial off the shelf (COTS) ICs, but not without costly upscreening and spaceflight reliability issues,” said Philip Chesley, Intersil’s vice president of Industrial Analog and Power products. “Intersil’s cost effective, radiation-tolerant plastic ICs overcome the reliability issues and hidden costs of COTS, giving satellite manufacturers the confidence and mission success assurance to launch and operate mega-constellations.” The ISL71026M radiation-tolerant 3.3V CAN transceiver provides serial data transmission at speeds up to 1Mbps. Up to 120 transceivers can be connected to a single CAN bus to reduce cabling/harness size, weight and power (SWAP) costs for satellite command and telemetry systems. Key Features and Specifications of ISL71026M ·        Operates at input voltage range from 3V to 3.6V ·        Quiescent supply current: 7mA (max), Listen mode supply current: 2mA (max) ·        Compliant with ISO 11898-2 physical layer standard ·        Bus fault protection up to ±20V, and loopback/listen mode ·        Cold spare capability: powered down devices/nodes without affecting active devices operating in parallel ·        Characterized radiation-tolerant to 30krad(Si) and SEE at LET = 43MeV•cm2/mg The ISL71444M rad-tolerant quad RRIO op amp provides low power, low offset voltage, and excellent output noise performance. Its SET recovery of <5µs eliminates external filtering. Key Features and Specifications of ISL71444M ·        Wide single and dual supply range from 2.7V to 40V ·        Wide gain bandwidth (GBW) product of 19MHz ·        Very low input offset voltage of 300µV ·        Low current consumption per amplifier of 1.1mA typical, and high slew rate of 60V/µs ·        Characterized radiation-tolerant to 30krad(Si) and SEE at LET = 43MeV•cm2/mg The ISL71001M rad-tolerant 6A synchronous buck regulator with integrated MOSFETs delivers high peak efficiency up to 95%, and steps down 5V and 3.3V primary rails to POL inputs as low as 0.8V for FPGAs, CPLDs, DSPs, CPUs and peripheral I/Os. Key Features and Specifications of ISL71001M ·        Operates at input voltage range from 3V to 5.5V ·        Tightly regulated output voltage externally adjustable from 0.8V to 85% of Vin ·        Fixed 1MHz switching frequency for reduced filter size ·        +/-1.2% referenced voltage, and compensation free ·        Bidirectional SYNC pin synchronizes two devices 180° out of phase ·        Provides adjustable output voltage, analog soft-start, input/output undervoltage, overcurrent protection, and power-good output voltage monitor ·        Characterized radiation-tolerant to 30krad(Si) and SEE at LET = 43MeV•cm2/mg Intersil space-communications ICs immune to single-event effects   Intersil here today announced a family of radiation-hardened (rad-hard) power-management components designed to withstand the potentially destructive, heavy-ion environment of space. Single-event effects (SEE), as they are known, are becoming an important issue to communications-system designers as the size of power-control devices decreases and demand for bandwidth increases the complexity of spacecraft systems. Up till now, ionizing radiation effects have been mitigated by either part-level hardening or by shielding sensitive electronics, Intersil said. But the nature of SEEs makes shielding the new generation of components less effective. Intersil's new family of rad-hard power management devices takes advantage of the company's dielectrically isolated, hardened-silicon-gate wafer fabrication process. Specifically designed to deliver highly reliable performance in harsh radiation environments, the process has been used to produce ICs vital to integrated communications applications, such as pulse width modulators (PWMs), voltage references, voltage regulators, MOSFET drivers and comparators. "Intersil devices enable the design of satellite electronics systems with greatly enhanced reliability and operability," said Nick van Vonno, senior scientist for Intersil's space and defense product line. "Combining Intersil's power management design expertise with the company's robust rad-hard processes has resulted in the first power management device family hardened to guaranteed high levels of SEE," he added. "This is a strong value proposition, as it is impractical to shield against this environment." Intersil's SEE family includes the Star*Power line that features a series of power management ICs. Several of Intersil's Vulcan DC-DC power conversion modules, as well as the Star*Power Gold family of power MOSFET devices, is also included in the SEE family. The devices are hardened to total ionizing dose levels of 300 krad (Si) and are available in reliable hermetic packages. They are designed for enhanced SEE hardness, with a design objective linear energy transfer (LET) rating of 82 MeV/mg/cm2. SEE hardness is achieved by a combination of hardened processing and specific design techniques such as redundancy and error correction. The Star*Power and Star*Power Gold series both spans six voltage ranges from 30 to 250V. The Star*Power MOSFET devices are optimized for low on-resistance and superior total ionizing dose performance, while the corresponding Gold devices are optimized for low gate charge and superior SEE hardness. The Star*Power DC-DC converter modules offer highly efficient power conversion capability with total dose hardness of 100 krad (Si) and SEE hardness of 82 MeV/mg/cm2. The Intersil Vulcan line of hybrid DC-DC converter modules leverages the Star*Power rad-hard components. These highly efficient converters support a wide range of input and output voltages, reflecting spacecraft design trends towards higher DC bus voltages. The Vulcan modules are rated at 100 krad (Si) total ionizing dose and feature the same SEE hardening to LET values of 82 MeV/mg/cm2.   Chip duo targets power supplies for small satellites  Renesas Electronics claims to have launched the space industry’s first plastic-packaged, radiation-tolerant PWM controller and gallium-nitride (GaN) FET driver for DC/DC power supplies in small satellites (smallsats) and launch vehicles. The chip duo is especially designed for isolated flyback and half-bridge power stages and motor control driver circuits in satellite buses and payloads. The smallsats form large constellations operating in multiple low Earth orbit (LEO) planes and provide global broadband internet links and high-resolution imaging for sea, air, and land asset tracking.                       The ISL71043M PWM controller, which provides fast signal propagation and output switching, features maximum supply current of 5.5 mA, which reduces power loss by more than three times. Moreover, ISL71043M offers the adjustable operating frequency of up to 1 MHz, and that enables higher efficiency and the use of smaller passive filter components. The ISL71040M, a low-side GaN FET driver, ensures reliable operation by precisely controlling the gate driver voltage to +3%/−5% in hostile temperature and radiation environments. The chip’s split outputs adjust the turn-on and turn-off speeds, and its high current source and sink capability enable high-frequency operation. The ISL71040M chip operates with a supply voltage between 4.5 V and 13.2 V, and it includes both inverting and non-inverting inputs. Renesas said that both devices are characterization-tested at a total ionizing doze (TID) of up to 30 krads (Si) and for single-event effects (SEE) at a linear energy transfer (LET) of 43 MeV • cm2/mg. Both devices operate over an extended temperature range of −55°C to 125°C. The ISL71043M PWM controller is available in a small 4 × 5-mm SOIC plastic package, which reduces the PCB area up to 3× compared to competitive ceramic packages. And the ISL71040M radiation-tolerant low-side GaN FET driver is available in an eight-lead 4 × 4-mm TDFN package.        Electronics Rocket into a New Frontier                                           Featured Resources Vishay Super 12 Harsh Environments Technology Figure 1: First Launch of the Orion Crew Vehicle.    With the recent Orion spacecraft test flight, humanity is once again attempting manned spaceflight beyond low Earth orbit (LEO). The test launch marked the first time since the end of the Apollo mission in 1974 that a manned-capable spacecraft had flown so far from our planet. Space exploration technology has changed dramatically since that time, but the dangers that future explorers and their equipment will face has not. Radiation, extreme temperature fluctuations, and intense vibrations at liftoff are just some of factors that engineers must handle when designing electronics to operate in the harsh environment of outer space. Figure 2: Nanosatellite for NASA’s CubeSat Initiative.  While you might think that these are problems of thin tie-wearing engineers, nothing could be further from reality. Today you don’t need a NASA-sized budget to get into space, or at least into near-space. Many makers are engaged in the burgeoning field of amateur space exploration. Science experiments are now routinely tethered to weather balloons, and if you’re really lucky you can get a nanosatellite launched into orbit thanks to NASA’s CubeSat initiative. Regardless of your budget, the operating environment of space travel is tough on electronics. There are numerous design techniques and engineering principles to keep in mind when designing electronics that are meant to operate in space. Before we jump into the details, let’s first get a better understanding of the challenges posed by operating electronics in outer space. The Operating Environment                                     Figure 3: Source of radiation and high-energy particles in space.  Earth’s magnetic field provides a defensive shield that protects us from being inundated by highly energetic particles (protons, electrons, and heavy ions) and radiation. These particles can include cosmic rays that come from beyond our solar system, as well as particles that are ejected from our Sun during Solar Particle Events (SPE). As we move beyond the safety of our planet, these particles increasingly take a toll on sensitive electronics. High-energy particles can affect electronics in multiple ways, and someone has taken the time to categorize them with regard to semiconductors: Single Event Transient: High-energy particle affects a particularly sensitive component resulting in a transient current or voltage spike. Single Event Latchup: Particle strike causes an electrical short between components on an integrated circuit resulting in circuit malfunction, but recovery is possible through a reboot of the affected system. Single Event Burnout: A latch up event that results in the affected device being destroyed. Single Event Upset: Internal build up charge causes a ”bit flip” in a memory or logic device (more about this later.) Displacement Damage: Accumulation of defects to the structure of silicon due to high-energy particle impacts. Total Ionizing Dose: Buildup of positive charges in insulators and oxide over time result in faulty circuit behavior. Thus, various particle events can cause numerous problems that fundamentally alter the operating characteristics of components. Spurious (i.e., “false”) currents can be induced in circuits resulting in incorrect circuit operation. Even worse, microchips can be destroyed due to excess induced power. If enough charge accumulates, bits in a processor or in memory can be flipped, resulting in data corruption. If the corrupted data plays a role in controlling a critical subsystem such as navigation or engine control, it is possible to lose the entire spacecraft. Radiation is just one concern. Extreme variation in temperature can occur over very short time periods, from hundreds of degrees below freezing to hundreds of degrees in the other direction depending on a spacecraft’s orientation and distance from the Sun. If not handled properly, thermal stresses can cause unpredictable circuit behavior at best and catastrophic failure at worst. Space electronics must also handle problems that can occur before a spacecraft ever leaves Earth’s atmosphere. Violent vibrations induced during rocket-assisted launches wreak havoc on components and interconnects if they are not designed to tolerate such extreme forces. Build It Tough Both radiation and temperature extremes require a variety of unique design techniques when building electronics to reliably operate in outer space. At the silicon level, individual components are altered in fundamental ways to provide better resiliency. Other design techniques include redundancy, where additional and/or redundant components, circuits, or entire systems may be employed in the design. Lastly, there are operational considerations to protect onboard electronics. Let’s take a look at some of the design techniques in each category: Special Design Consideration at the Silicon (Component) Level: Component selection is a critical phase of designing a space-based system. There are many differences in the engineering and manufacturing techniques of components that to be considered: “Radiation hardening” is the term given to a variety of design and manufacturing techniques to re-design electronic components (most commonly semiconductor-based components) to be more resilient to exposure to high-energy particles. A common method is to replace the silicon substrate of semiconductors with “silicon-insulator-silicon” substrate (SOI) or a sapphire substrate (silicon-on-sapphire, or SOS). The alternative substrate allows semiconductor components to be very good at curtailing the spread of stray currents to neighboring elements, should one element be struck by a high-energy particle. Other semiconductor design tips you may not know, when designing for operation in space: Bipolar junction transistors are more tolerant of radiation strikes than CMOS circuits in some applications. Replacing dynamic random access memory (DRAM) with static RAM is a design trade-off that is often chosen since SRAM is more tolerant, though at the expense of cost and physical layout size (less memory per unit area). Robust and Redundant Systems: After selecting robust components that can meet the operating requirements, the next key step is to ensure the system as whole is well architected and that interfaces between components are as well designed as the components themselves. Material selection is one key aspect of ensuring good radiation protection for internal systems. Copper and aluminum shielding is an option to protect a spacecraft’s circuitry from certain particles, though this is not effective for higher energy cosmic rays. Lead is another option for shielding. Hamming distance functions and parity bits can be used for memory error detection and correction. The Hamming function is a software-based solution and does add some processing overhead. Modular redundancy techniques such as Triple Modular Redundancy (TMR) is a design topology where redundant copies of the same circuits are used to process the same data inputs. The outputs are then passed to a “majority gate” that compare the outputs from the redundant circuits and decide the correct solution to pass on to systems downstream. This has the advantage of being faster than the Hamming solution as it is done all in hardware. The Data Processing System (DPS) aboard the now defunct U.S. Space Shuttles had five redundant backup systems, one of which ran independently developed software from the rest as a failsafe measure. The use of a watchdog timer is another design technique to detect and recover from a computer glitch. A watchdog timer works by counting down and every so often the main processor resets the watchdog before it reaches zero. Should a main computer glitch occur and the watchdog timer hits zero, the watchdog will generate a reset signal that will restart the main processor and place it into a safe mode before resuming operations. Electromechanical systems are also employed on spacecraft that must contend with high temperatures of the inner solar system before venturing into the cold of the outer solar system. Temperature sensors, when combined with mechanical systems such as louvers, can safely regulate the internal temperature of a spacecraft. While we’ve talked a lot about semiconductor design strategies, it should be worth highlighting that interface between subsystems is another potential issue for spacecraft electronics. Interconnects and cable connectors between systems must also be robust to withstand spacecraft launch and possibly even re-entry.  Repair and maintenance for space stations is also a consideration. Thoughtful design is a part of space operation, possibly learned the hard way. Remember the round and square CO2 scrubbers in Apollo 13? The crew had moved to safety in the Lunar Module that was designed for two people for 36 hours of use, not three people for 96 hours.    Figure 4: Astronaut John Swigert is shown to the right of the square device they hacked together to adapt the square scrubber cartridges to fit that on the Lunar Module, which used round cartridges. And yes, that is duct tape.  We know that purposefully keeping designs consistent and simple can save lives and cost. Most engineers would label a beautifully simple yet very efficient design as “elegant.” Although intended for use on Spaceship Earth, Phoenix Contact’s SUNCLIX Photovoltaic Connectors require no tools to assemble, and would qualify as an “elegant design” for many. Robust, redundant systems are an engineering methodology, but elegant design flows from experience, innate talent, and creativity. Figure 5: Phoenix Contact’s SUNCLIX Photovoltaic Connectors demonstrate elegance in design. (Source: Mouser) Operating Procedures: Lastly, there are methods in operation of spacecraft and associated subsystems to reduce the impact space: Orbit selection is key, as certain orbits will reduce exposure to high-energy particles. Orbits such as those favored by CubeSats can be safe enough such that commercial-off-the-shelf (COTS) components can be used (without radiation hardening.) De-energizing all but the most critical systems before entering into regions of space where high radiation is expected is often employed to preserve onboard systems. Beyond the Final Frontier Outer space is not the only harsh environment where electronics may be installed. There are plenty of harsh operating environments right here on Earth. Consider the following environments: Polar regions: Extremely low temperatures Desert/Rain Forest: High temperature or very humid environments Deep Ocean: High pressure, low temperature Industrial: Chemically corrosive environments Medical: Inside the human body Each environment presents unique operating challenges. From a systems engineering perspective, understanding the operating environment is key in making solid design decisions and considering all potential environmental conditions early in the design process. And don’t assume a one-fits-all-solution will work in every situation. Design issues are complicated by the fact that once launched, the ability to perform maintenance on a spacecraft is very limited, depending on the mission. Thus engineers must employ a multitude of techniques to ensure that systems can handle the countless possible failure scenarios that can be encountered. Thus, radiation hardened components are more expensive than conventional-use, COTS counterparts, even though the hardened components can sometimes technologically trail behind by five or more years. Also consider that while all engineering ventures must strike a balance between cost, schedule, and technical performance, space-based systems must contend with unique scheduling challenges. Certain missions that target particular destinations may have launch windows that are only a few days. Missing a deadline may mean waiting years for another opportunity. In short, design for space missions is not for the timid. To find out more about spacecraft electronics component design and manufacturing (or if you have trouble sleeping), there are years’ worth of U.S. military standards (a.k.a. MIL STD and MIL-SPEC) online at everyspec.com,                    Radiation-hardened space electronics enter the multi-core era The pace of embedded computing technology development is placing pressure on satellite and spacecraft designers, who must deliver reliable systems at low costs.                                     The pace of embedded computing technology development is placing pressure on satellite and spacecraft designers, who must deliver reliable systems at low costs. Space is a dangerous place, especially when it comes to sensitive electronic components like microprocessors, solid-state memory, and network interfaces. The problem is radiation; space has a lot of it, and most modern electronic components were not designed to operate in a radiation environment. Levels of radiation that occur in space can cause a variety of problems for electronic components, ranging from complete burnout to the occasional bit flip that can corrupt some data and render the reliability of even untouched data open to question. There are ways to specially design radiation-hardened electronic parts to resist the effects of radiation, but it's expensive to do this. Moreover, overall demand for rad-hard electronic parts is relatively low, which can drive up their costs even more.            The growing use of space-based electronics for manned spacecraft, satellites, and deep-space probes is putting pressure on the rad-hard community to deliver technology with high performance and low cost. Then there's specially shielded packaging of electronic parts to keep radiation at bay. Not only is this approach expensive, but it also can be heavy enough to adversely influence launch costs. There are other ways of dealing with space radiation, ranging from redundant subsystems, selective shielding, and upscreening commercial off-the-shelf (COTS) electronics for enhanced reliability. Among the challenges of space operations today are balancing electronics costs, capabilities, and reliability such that systems are good enough to operate in specific radiation environments for expected durations to meet mission requirements. Space radiation effects There are several ways that electronic parts designers can radiation-harden their devices. One of the most common is to harden for total-ionizing-dose radiation - or the amount of radiation the device is expected to withstand for its entire life before problems occur. A typical requirement is for 100 kilorads of total-dose radiation hardness. The evolution of today's advanced electronic components, however, also is changing the total-dose picture. Specifically, the shrinking size of circuits on today's most modern chips is lessening their vulnerability to total-dose radiation. "As technology nodes decrease in size - from 90 nanometers to 14 nanometers - total ionizing dose performance naturally improves," says Michelle Mundie, business area director of standard products at rad-hard specialist Cobham Semiconductor Solutions in Colorado Springs, Colo. This phenomenon is a double-edge sword, however, because the steady shrinking of chip geometries also makes these devices even more vulnerable to other kinds of radiation effects, namely single-event upset (SEU) and single-event latchup (SEL). "Single-vent effects like latchup are becoming more of a problem, so we have to design for those effects. "Devices today are more sensitive to radiation at the gate and transistor level."            Curtiss-Wright is providing the company's radiation-tolerant Smart Backplane technology for the European Space Agency's Vega-C expendable space launch rocket. Single-event upset can corrupt data when a radiation-charged particle flips a data bit from a one to a zero, or vice versa, which corrupts data. SEU typically does not physically damage an electronic device, only the data it contains or that flows through it. Single-event latchup, however, can be damaging if it causes a short circuit that triggers thermal runaway. Device designers must consider these potential threats. There are several design approaches to mitigating radiation effects, which include radiation hardening by design, selective shielding, redundancy, and error-checking. One of today's most notable rad-hard by design projects is the High Performance Spaceflight Computing (HPSC) Processor Chiplet program. Rad-hard by design Rad-hard by design involves designing an electronic component from the ground up to resist radiation effects. It can be one of the most expensive and time-consuming approaches, but sometimes it's the only solution for electronic components that are crucial for protecting human lives or safeguarding important orbital and deep-space missions. U.S. government space experts are working with the Boeing Co. to create a new generation of radiation-hardened microprocessors for a wide variety of space applications to provide some of the most advanced processor technologies with broad industry and software support for future space missions. Sponsors of the HPSC project are the U.S. National Aeronautics and Space Administration (NASA) and the U.S. Air Force Research Laboratory at Kirtland Air Force Base, N.M. Industry experts from the Boeing Solid-State Electronics Development segment in Seattle are carrying out the program, based on a $25.9 million contract awarded last March by the NASA Goddard Space Flight Center in Greenbelt, Md.                  Curtiss-Wright is delivering the company's MnACQ-2000 Miniature Network Data Acquisition System, shown above, for the NASA Orion spacecraft and the Space Launch System (SLS). These data-acquisition systems are hardened against the effects of space radiation. The HPSC program is intended to develop rad-hard microprocessor technology that will replace or augment previous generations of rad-hard microprocessors, such as the RAD750 from the BAE Systems Electronic Systems segment in Manassas, Va., and the RH-1750A, RH-32, and Advanced Spaceborne Computer Module (ASCM) from the Honeywell Aerospace segment in Clearwater, Fla. Managing the HPSC project are experts at the NASA Jet Propulsion Laboratory (JPL) in Pasadena, Calif., led by Richard Doyle and Raphael Some. The NASA Goddard Space Flight Center is managing the HPSC contract. The program is developing technologies for a next-generation, general-purpose, multi-core space processor to meet on-board computing needs of future manned spacecraft and space robots. The four-year project is expected to deliver a next-generation, rad-hard space processor based on the ARM processor architecture to provide optimal power-to-performance for upgradeability, software availability, ease of use, and relatively low costs. Although previous generations of rad-hard space processors like the RAD750 have performed well for years, "there are needs now that are well in excess of what that processor can do. Today's radiation-hardened space processors typically are single-processor systems based on existing commercial or military computers. They operate at maximum required throughput, fault tolerance, and power levels. Air Force and NASA space experts, however, say they anticipate future missions that will require an increase in throughput and wider variations in throughput, fault tolerance, and power levels. Commercially developed technology "We're basing this device on commercially developed, well-supported IP, and making sure there is a wide user base and software support - something that is well-supported by industry . Air Force and NASA experts have defined the ARM-based hardware and companion Linaro system software as the HPSC processor baseline architecture. Boeing embedded computing experts will develop a new space processor design that will provide orders of magnitude improvement in performance and performance-to-power ratio as well as the ability dynamically to set the power-throughput-fault tolerance operating point. The HPSC project also will use Radiation Hard by Design (RHBD) standard cell libraries, as well as the ARM A53 processor with its internal NEON single instruction, multiple data (SIMD) design. "You really need the ability to do radiation hardening by design, applied to standard cells, etc., that allow you to use a modern semiconductor process. NASA experts are looking at three broad application areas for the next-generation HPSC microprocessor: vision systems, model-based reasoning for on-board autonomy, and high-rate instrument processing . Vision systems would involve space applications like obstacle avoidance. "We need to process imagery to determine where you should and should not land, and in real time . Model-based reasoning for on-board autonomy could enable spacecraft designers and space mission managers to migrate much of the mission-planning and resource-management tasking to the spacecraft, rather than rely on ground controllers for those jobs. NASA experts also are thinking ahead to future deep-space missions in which ground controllers may not always be in touch with the spacecraft, so must rely on the spacecraft to make some of its own decisions. High-rate instrument processing involves demanding digital signal processing for sensors and instruments like synthetic aperture radar and hyperspectral electro-optical sensors. "We want to migrate some on-board data processing on-board the spacecraft so we can downlink data of interest, rather than just the raw data. In addition, NASA experts are looking to Boeing to develop enabling technologies for a space processor that not only is radiation hardened, but also can manage its own electricity demands to preserve power resources - especially on deep-space missions far from Earth. Aitech offers the E905 three-slot, cold-plate-cooled, space-rated embedded computing enclosure for mission-critical space applications, built on a 3U CompactPCI platform using machined aluminum. Smart power usage A key goal is the ability to trade dynamically between processing throughput, power consumption, and fault tolerance. "We want to be power-aware in our processor, and be able to ramp-down the processor for just what we need. That is kind of missing today . "We are looking for the ability to tailor power, processing, and fault tolerance. Flexibility is one of the key objectives for HPSC." Fault tolerance management middleware will enable the processor to detect and log errors; remove services likely to experience hard failures; respond to uncorrectable errors; and implement n-modular redundancy, checkpoint/rollback, or other high-level fault tolerance. Additional applications for the HPSC processor will include military surveillance and weapons systems, human-rated spacecraft, habitats and vehicles, and robotic science and exploration platforms. System applications range from small satellites to large flagship-class missions. Additional space computing tasks of the HPSC processor will include command and data handling, guidance navigation and control, and communications like software-defined radio; human assist, data representation, and cloud computing; high-rate real-time sensor data processing; and autonomy and science processing. Boeing will provide prototype radiation-hardened, multi-core computing processor Chiplets, system software, and evaluation boards for Chiplet test and characterization. The Chiplets each contain eight general-purpose processing cores in a dual quad-core configuration, and interfaces to memory and peripheral devices. "The period of performance is 45 months, so by late 2020 we're expecting Boeing to provide a processor chip or chiplets, packaged chiplets and bare die, and evaluations boards populated with chiplets to exercise the silicon . "These chiplets will not be space-qualified; the focus of this project is on the silicon."                       Embedded computing companies that specialize in rugged COTS technology are adapting design techniques to provide rad-hard computing for space. Shown above is the Aitech SP0-S enhanced space-qualified 3U CompactPCI single-board computer. System software infrastructure will support real-time operating systems and Unix/Linux parallel processing to support hierarchical fault tolerance ranging from single Chiplet deep-space robotic missions to multi-Chiplet -redundant human spaceflight missions. "We also expect system software, including operating system, compilers, debuggers, a Linux operating system, and a real-time operating system,. The HPSC processor will include Serial RapidIO (SRIO) for high-bandwidth communications, and several interfaces to high-speed, off-chip memory. The SRIO interfaces also can function as advanced microcontroller bus architecture (AMBA)-bus bridges to tile or cascade several processors to increase bandwidth or improve fault tolerance. The SRIO interface also can extend the HPSC processor to other SRIO-enabled processing devices such as field-programmable gate arrays (FPGAs), graphics processing units (GPUs), and in the future to other application-specific integrated circuit (ASIC)-based coprocessors. NASA and the Air Force will consider a flight-qualification program when the HPSC program concludes in late 2020 or early 2021. After that, it's reasonable to assume the technology will be ready for deployment. it"s speculates that HPSC technology could be deployed for at least 10 years before designers must look at a new generation of rad-hard microprocessors. Looking beyond microprocessors Outside the realm of the HPSC program, NASA experts are considering plans for additional radiation-hardened computer components, such as general-purpose graphics processing units (GPGPUs), field-programmable gate arrays (FPGAs), as well as volatile and non-volatile memory. The problem right now is funding. For the HPSC program "we looked at a number of processing architectures, and the biggest bang for the buck was a general-purpose, multi-core processor. For the future, nevertheless, "we have interest in some sort of paring of a general-purpose multicore processor with a rad-hard FPGA or GPGPU. There is interest, but we can't say that we have funding for that, but there's definitely interest. "We're also interested in advancing volatile and non-volatile memory and networking rad-hard technologies . We have interest in developing a rad-hard ecosystem around that HPSC processor." COTS electronics for space While it's true that some space applications require the most expensive radiation-hardening solutions, the reality is that space systems designers must do the best they can to use commercially available electronic components for space applications. Often this approach involves taking a hard look at whether the intended application is life- or mission-critical, the expected severity of the radiation environment in which the overall system will operate, and the duration of the planned mission, and then designing a radiation-tolerant system that's good enough. Low-Earth orbit (LEO), for example, does not experience the same radiation levels that higher orbits or deep-space have. A growing number of LEO satellite applications today, moreover, have relatively limited life cycles. Some Earth-observation projects, in fact, are expected to last for less than five years. "There's a push to put a lot more hardware on LEO orbits lasting from three to five years for space observation," says George Romaniuk, director of space product management at Aitech Defense Systems Inc. in Chatsworth, Calif. "The orbit is low, so the requirements are not that stringent. On the other hand, we see groups that will be for lunar or asteroid exploration beyond Earth orbit. They want to stay for a very, very long time (18 years, minimum) so the market is starting to segment." Applications in lower-Earth orbits that may be of relatively short durations - and that could tolerate the occasional data upset - are a particularly promising market for COTS electronics suppliers, particularly for cost-sensitive applications like small satellites. "Our lives are basically lives of compromise," Romaniuk says. "We may not have $7 million to create something nice, but we have to piece together things that will provide performance and reliability." Cobham has specialized for decades in selecting commercially developed electronic parts that are appropriate for some space applications. The company uses upscreening and a variety of other testing. The company started their rad-hard upscreening business about 20 years ago with a focus on solid-state memory, and now is expanding into microcontrollers and mixed-signal analog products. "With changing market pressures from the small satellite industry, and the drive to smaller device sizes, a lot of the space market is looking at flying at COTS products," says Cobham's Mundie. "We knew the need was there, and our focus is changing to ensure we are offering our right products to the industry. It is a challenge for us to identify COTS products that will work in a variety of applications." Cobham is using upscreening technologies and years of knowledge to create a radiation-hardened CAN bus network interface. Multi-core redundancy Some technological developments in the COTS computing industry are providing serendipitous advantages for space systems designers. Not only are deeply submicron geometries naturally resistant to total-ionizing-dose radiation, but modern multicore processor architectures also offer opportunities for system redundancy. Embedded computing designers at the Curtiss-Wright Corp. Defense Solutions Division in Ashburn, Va., are using multi-core processors not to block radiation-induced single-event effects, but to recover gracefully without system disruption when upsets occur. "Where we are now using multi- core processors to speed up com- puting, we also can use that to our advantage by running the same code in multiple cores," says Paul Hart, chief technology officer and technical fellow of avionics and electronics at the Curtiss-Wright office in Christchurch, England. "We run main code in one core, and duplicate code in another core that run in lockstep," Hart explains. Running identical code in three separate processor cores enables the system to detect a malfunction in one core, shut down the offending core, and continue operating based on no detected malfunctions in the other two. "If a single event does occur, it will cause one of the cores to lose lock," Hart says. "If that happens the higher-level supervisory system that operates above it will reset the device. It will take in the order of seconds to reboot a typical embedded application; while the upset core is rebooting, the other two carry on. You're fully recoverable after a bit flip." Radiation creep Hardening electronic systems to the effects of radiation isn't just a space problem any longer. Aircraft flying at altitude, at about 30,000 feet and above, also are starting to experience radiation-induced effects. "There are 500 times more neutrons at 30,000 feet than there are on the ground," points out Aitech's Romaniuk. If commercial avionics systems designers aren't considering radiation hardening today, they soon will be. The shrinking of commercially developed microprocessor architectures and other electronic devices will continue making the problem worse. ERAFT                                            ANATOMY OF SPACE CRAFT        BepiColombo’s cruise configuration A spacecraft has a number of essential components, such as an engine, power subsystem, steering system and communications system, in addition to science instruments. Most of these systems are housed in a section called the service module, while the science instruments make up the payload module. These are encased inside the spacecraft’s main structural unit and connected by a ‘harness’, the electrical framework on which the spacecraft electronics systems communicate.                                                      Propulsion and thrust : The propulsion system that a satellite carries is dictated by the orbital position that it needs to reach and by the type of mission. Additionally to the launch vehicle-provided propulsion, there may be an upper stage (e.g. Fregat) that delivers the spacecraft to a higher or to an escape orbit. The spacecraft itself may carry its own (attached or jettisonable) propulsion module for orbital manoeuvres or orbit adjustment. Finally, smaller thrusters may be  included for fine orbit adjustments and orbit maintenance, the so-called stationkeeping. ‘Cold gas’ propulsion will be used by Gaia and Lisa Pathfinder and is the simplest type of chemical propulsion. The propulsion system consists of pressurized gas and a nozzle, and whenever thrust is needed the nozzle is opened and some of the gas is expelled. Most satellites also have simple hydrazine thrusters and/or reaction or momentum wheels to control attitude and orbit. Solar-electric propulsion using ion engines is an alternative way to travel in space. Ion engines shoot out a spray of ionized particles to deliver their thrust to push the spacecraft on its way. Ion engines typically get the high power required to ionize the propellant particles from the spacecraft’s solar panels. They work their magic in a leisurely way and can go on pushing gently for months or even years, for as long as the Sun shines and the small supply of propellant lasts. ESA’s SMART-1 spacecraft used ion propulsion to travel to the Moon in 2003; Bepi-Colombo, launching in 2015, will also use this method combined with gravity assists from flybys of the Earth, Venus and Mercury to finally enter orbit around Mercury. Studies are also being made in Field-electric propulsion systems (FEEPs), an advanced electrostatic propulsion concept that uses liquid metal and electric fields to create an acceleration                                                                   POWER : A spacecraft must generate and distribute adequate power to operate its subsystems and instruments. The power generation is usually catered for by solar panels, which convert sunlight into electricity. When the spacecraft is in eclipse, that is in the shadow of a celestial object or turned away from the Sun and the panels thus do not generate power, batteries kick-in. Depending on the type of spacecraft, solar panels may take on a traditional winged shape (for three-axis stabilized satellites) or be wrapped around the cylindrical body of a spinning spacecraft. Different spacecraft units may require different voltages. Some spacecraft have central units to convert and stabilise the ‘raw’ voltage produced by the solar array before it is distributed, while for others the conversion happens within the units. Planck spinning in space                                                           NAVIGATION SYSTEM A navigation system, usually referred to as ‘Attitude and Orbit Control’ is essential for the spacecraft to maintain its attitude, so that it can be directed towards its intended destination.  This capability is also required to keep its solar panels pointed towards the Sun and its instruments pointing at specific targets. Attitude control is achieved with electronic 'eyes' (sun and star sensors).  These can sense the location of the Sun and track the stars allowing the spacecraft’s position and orientation to be calculated. A propulsion system or reaction wheels controlled by appropriate software ensure then that the spacecraft is moved or oriented appropriately.  Most modern spacecraft are ‘three-axis stabilised’ so that they sit 'upright' in space, while other satellites may spin to achieve stability. For example, Planck revolves about a Sun-pointing axis once per minute to stabilise its attitude.                                     COMMUNICATION  AND DATA HANDLING The communications system returns science data, that is passed on to the scientists,  and 'housekeeping' data, called telemetry, which allows engineers back on Earth to monitor the condition of the spacecraft. The on-board communications system also receives all incoming commands. Communications may be carried out at different frequencies using a combination of dishes and high- or low-gain antennaes.                                                         SCIENCE PAYLOAD Instructions are received from the ground in the form of individual commands or sequences to be executed at pre-defined times. The commands are processed by the data handling system that either executes them immediately or stores them for later execution. The data handling system comprises processors, on-board memory, and analog to digital and digital to analog conversion systems. Herschel’s cryostat vacuum vessel Science instruments and experiments make up the payload, the number and type of which depends upon the objectives of the mission and the size of the individual payload components. The payload elements and the consortia providing them are selected by means of an open call before the mission is selected. The scientific payload is normally funded by member states via the scientific members of the consortia.                                                     Astrophysics missions   Missions that study the Universe – stars, galaxies, black holes and so on – study objects by collecting the radiation they emit, using telescopes, cameras and detectors.  They usually have a large mirror to collect light from distant astronomical objects. The larger the mirror, the more light it can collect, and the fainter the object it sees. The surface of the mirror has to be precisely shaped and perfectly smooth, since the slightest roughness distorts the final image. Once light from an object, like a star, falls onto the primary mirror, it is directed towards a smaller secondary mirror where the light is focused and directed to the instruments. Here, the light is detected and analysed, and the results recorded by the onboard computer to eventually be relayed back to Earth.   A ‘baffle’ or sunshield surrounds the telescope, limiting the amount of stray light from the Sun, Earth or Moon that can leak onto the detectors and spoil the results. A sunshield also helps radiate excess heat into space, maintaining a stable temperature. A sophisticated cooling system may also be required; for Herschel and Planck the detectors must be cooled to temperatures close to the coldest temperature reachable in the Universe – absolute zero, or –273.15°C. This is achieved using a cryostat, which typically contains liquid superfluid helium at temperatures lower than -271°C. The role of the cryostat is fundamental because it determines the lifetime of the observatory: the superfluid helium evaporates at a constant rate, gradually emptying the tank. Rosetta’s Philae lander on comet nucleus                                                             Solar System missions   Spacecraft in orbit around a planet host a wide range of instruments to record information about the planet’s atmosphere, surface, and even subsurface. The payload may include cameras to take images; spectrometers to determine the chemical composition of planet’s surface and atmosphere; radar to probe the subsurface, and instruments to study the way in which the planet interacts with the Sun’s magnetic field. The payload may also include a lander, such as Cassini’s Huygens lander that touched down on Saturn’s moon Titan in 2005, and Rosetta’s lander Philae, which will probe the surface of Comet 67P/Churyumov-Gerasimenko in 2014 by scooping up samples of the surface and analysing them in its on board science laboratory. Other missions may include a rover to explore a wider range of a planet’s surface; penetrators to probe the subsurface of a planet or moon to detect ‘earthquakes’; or they may have a sample return element, which must be capable of returning back to Earth with samples collected from the target.                                                    Fundamental physics missions   Missions like Lisa Pathfinder will validate in flight a completely new and previously untested method of observing the Universe. Lisa Pathfinder is tasked with testing technology that will lead to the detection of gravity waves, which are thought to be generated by massive objects like black holes. The mission consists of placing two test-masses in a nearly perfect gravitational free-fall, and of controlling and measuring their motion with unprecedented accuracy. This is achieved through state-of-the-art technology comprising inertial sensors, a laser metrology system, a drag-free control system and an ultra-precise micro-propulsion system.                                                        SLUSH – The Search for Life Using Submersible Heated drill                                                                              Spider Water Extraction System Water is essential to human spaceflight missions. It is an immensely valuable resource to sustain astronauts, and as a building block for rocket fuel or other valuable compounds. This is why In Situ Resource Utilization, or ISRU, is so attractive to both exploration and commercial ventures: using local resources means missions can start with lower supplies, or extend their missions far beyond what is possible with materials on-board. Autonomously harvesting water from asteroids, however, is a nontrivial process for space mining technology. Designed for a mission to water-rich asteroids (Carbonaceous Chondrites), Honeybee Robotics’ Spider Water Extraction System is a spacecraft that drills and acquires icy soil samples, extracts the water for later use, and disposes dry soil to prepare for another round of sample collection. The architecture enables each drill to generate significant down-force in the absence of gravity — the auger drills mounted on each leg provide anchoring force as they sample for water-rich material. The Spider Water Extraction System, developed as part of the World Is Not Enough (WINE) program, is designed to be resilient, with multiple systems integrated into spacecraft lander legs provide higher processing volume and system redundancy.  The architecture provides a combination of low mass and high strength to drill into tough icy and mineral composites that can be as hard as concrete, whether the material is hydrated or free water. It has demonstrated the ability to gather water from Carbonaceous Chondrite analog materials (hydrates) under thermal vacuum conditions. The Spider Water Extraction System has two modes of mobility on an asteroid, with the ability to walk across the surface and also hop using steam propulsion (with propulsion powered by water mined from the target asteroid). As such, it could be used as a pre-mining surveying technology or as a mining platform on its own.                                                                                            Sample Processing Systems Robotic’s geotechnical work focuses on the entire sample acquisition and analysis chain. Sample preparation is at the heart of this process: a well-prepared sample is essential for accurate geotechnical analysis. Automated sample processing and sample preparation systems must be rugged enough to withstand vibration and harsh environments, but also low-power and lightweight for mobile applications. Honeybee’s Mechanized Sample Handler (MeSH) is a prototype miniature centralized sample preparation station that could be mounted on a rover for a future mission to Mars. MeSH crushes small rock cores to powder, then sieves and distributes it in measured aliquots to one or more instrument inlet ports. This system provides a complete core-to-instrument processing solution. It features a fast, efficient, fully automated 8-axis mechatronic system. Honeybee’s Grinding/Polishing Station (GRITS) is an autonomous three-station operation that can autonomously grind and polish, measure thickness, and measure surface finish to produce very thin samples of rock for geotechnical analysis. The autonomous system produces thin sections, on the order of 30 microns, with a surface roughness of 0.3 microns or better. These samples can then be analyzed by reflected light, polarized light, or other techniques to understand the geological composition of the rock.      Spacecraft Design Electronic Sub-systems About the electronic design of satellites and spacecraft :  Introduction - Comparison of spacecraft electronic systems to an equivalent ground based unit. Power Systems - Solar cells, solar arrays; storage cells; regulation dissipative and non-dissipative, regulators linear and switched mode, noise reduction, filters, supply monitoring, decentralised regulation. Attitude sensing and control - Earth and Sun sensors, charge coupled devices, wedge and strip, crossed anode, magnetic sensors, search coil and fluxgate, magnetic torquers. Mechanisms & Housekeeping - Control monitoring; optical and magnetic, pyrotechnic actuators, bridge techniques. Harnesses - EMC magnetic and electric coupling, shielding efficiencies for near and far field, EMC outgassing ports, connector types, low and high voltage, printed circuit board types. Reliability - Design techniques, heat dissipation, latch-up, interface and single point failures, housekeeping requirements, components specification, failure rates, fabrication, radiation testing, effect of radiation, displacement and ionisation damage, transients effects, designing for radiation protection. Analogue design - Charge sensitive amplifiers, noise considerations, practical circuits, pulse shaping circuits, unipolar and bipolar pulses, base line depression, pulse pile-up, low frequency measurements. Example sessions - Electrical hardware circuits for past and present space missions will be described and demonstrated utilizing the project's development circuit boards.                                           Challenges in designing electronics for satellites           The earliest satellite designs were huge, heavy, and functionality was limited.  Nevertheless, satellite designs started evolving with the passage of time and a new era of satellite modeling began with the invention of microcontrollers (MCUs). Engineers were able to reduce complex circuitry to a few parts as MCUs integrated multiple components, reduced power consumption, and minimized overall housing size and weight as Printed Circuit Board (PCB) size shrank, too. The latest development to making space accessible is the CubeSat. What are CubeSats? According to CubeSat101, Basic Concepts and Processes for First-Time CubeSat Developers, “CubeSats began as a collaborative effort in 1999 between Jordi Puig-Suari, a professor at California Polytechnic State University (Cal Poly), and Bob Twiggs, a professor at Stanford University’s Space Systems Development Laboratory (SSDL).” The publication by the NASA CubeSat Launch Initiative goes on to state, “The original intent of the project was to provide affordable access to space for the university science community, and it has successfully done so.” Figure 1: CubeSats come in several sizes. The exactingly specific standards for CubeSats is one of the reasons why they are an affordable means to access space experimentation. (Image: CalPoly) CubeSats are defined in sizes based on a standard CubeSat unit (U). A “1U” CubeSat is 10 cm3 and weighs around 1 to 1-1/3 kilograms. Since the first CubeSat, larger sizes have evolved and are based on the original 1U size, varying in size as 1.5U, 2U, 3U, and 6U, with new CubeSat sizes always a possibility. Today, many of the National Aeronautics and Space Administration’s (NASA) CubeSats contain ARM, Atmel, Texas Instruments’ MSP430, and Microchip Technology PIC microcontrollers.There are many challenges to designing electronics for aerospace or space travel, however. Temperature, vibration, and radiation challenges  Designing for space is much more complicated than designing for standard electronics. Electronics for military, avionics, and aerospace are crafted to withstand the extreme temperatures, vibration, shock, and radiation effects commonly encountered at lift-off and outside the earth’s atmosphere. Temperatures vary along a wide range from -55°C to +125°C in space. For instance, the surface temperature of the Moon ranges from between approximately –200°C to +200°C. A satellite can be exposed to below-freezing temperatures and extremely hot temperatures within a short period of time, taxing all materials. Extreme temperature not only shortens the life of a component, but it also affects its everyday operational functionality. Casual electronic components cannot bear such temperatures or such a wide range of temperatures for long. Commercial off-the-shelf (COTS) components that are designed to withstand the required temperature range must be used. An electronic part or kit that is specifically designed to a level of performance and reliability may be subject to assurance processes within the industry’s supply chain. The processes are meant to establish a quality and reliability foundation for the electrical, electronic, and electromechanical components that end up in the industry’s critical applications. “These assurance processes, with inspections and tests possibly performed on a sample basis depending on criticality, are intended to identify defects and abnormalities that serve as warning signs of a potential for premature failure, reduced performance, and safety. One example of an industry that conducts assurance processes is the Automotive Electronics Council, or AEC. The AEC “was originally established by Chrysler, Ford, and GM for the purpose of establishing common part-qualification and quality-system standards,” per the AEC’s site at aecouncil.com. Components meant for space travel also have exacting standards. Temperature isn’t the only factor. Vibration at lift-off could mean the sudden application of 9.2 million pounds of thrust. The galactic cosmic rays in space pose another major challenge and are a “slowly varying, highly energetic background source of energetic particles that constantly bombard Earth,” per the National Oceanic and Atmospheric Administration (NOAA).The rays carry high-energy ions which are capable of energizing satellites electronics, resulting in malfunctioning and damages. Galactic cosmic rays (GCR) consist of heavy elements with high energy ions and no electrons. GCRs are concentrated with protons; they lose their electrons in the course of traveling through the galaxy at the speed of light. (See Figure 2 for more information.) GRCs can pass through a satellite or an astronaut’s skin.[viii] Satellites orbiting at low altitude are more affected by radiation.In order to protect electronic components from radiation, the components must be radiation hardened.                                     Figure 2: This illustration depicts two main types of radiation and how the magnetic field around Earth affects the radiation in space near Earth. Galactic cosmic rays are a variable shower of charged particles coming from supernova explosions and other events extremely far from our solar system. The sun is another main source of energetic particles. The sun spews electrons, protons, and heavier ions in “solar particle events” fed by solar flares and ejections of matter from the sun’s corona. Tin whiskers   The vacuum of outer space is also a good environment for tin whiskers to form. Pure zinc, tin, and cadmium plating are not allowed on components that qualify for existence in space. Limited power and housing dimensions Satellites are designed to remain in space for months or years and must have access to power. Solar power is the most likely source of energy to be used in space. The typical CubeSat is equipped with solar cells, however generating power with only a few cells means that the power supply is limited. Under these circumstances, large or power-hungry circuits are not easy to justify. Power consumption and size requirements can be reduced by using Integrated Circuits (ICs). One IC can achieve what was once achieved with a PCB covered with components. The advent of ICs contributed greatly to mankind’s capability in space. Compatibility with available power lines It’s possible that different ICs will require different voltage levels in a satellite. Separate voltage busses might power ICs with different voltage demands. In some cases, it is not practical to use low voltage levels as the voltages could drop significantly enough at the end of a bus to adversely affect operation. In such cases, choosing components with similar voltage level requirements might be preferable. By paying attention to the operating voltage levels of various ICs and components, designs avoid the need to provide several different power supply levels and corresponding voltage regulators. Using components with similar voltage level requirements reduces cost and energy dissipation. Redundant systems A typical satellite mission lasts for years, and repairs are uneconomical. Occasionally a member at the International Space Station or other entity might attempt to fix an issue, however this is a dangerous feat. Therefore, it’s essential to endeavor for flawless designs that are going to function throughout a satellite’s mission life without any issues. For critical missions, redundant systems are often installed in case a part or system malfunctions or dies. Thus, if something fails to operate properly, the redundant system can be implemented either automatically or deployed via radio signal from earth. Interestingly, a side-effect of designing for operation in space is the flexibility of being able to continue a mission even after disconnecting primary systems. Telemetry for monitoring all units Although satellite designs are finalized after extensive design reviews, detailed analyses, and multiple test procedures, unfortunate circumstances may still occur. It is essential to keep track of the various voltage, current, and temperature levels of all the major components. For that, data must be transmitted from the satellite to monitoring stations on earth. Automated, remote monitoring is called telemetry. If satellite telemetry records any significant abnormalities, the associated unit may be disconnected immediately to avoid damage to other systems. Designing systems for space used to be a government-only effort. Today, companies like SpaceX are launching satellites from earth for commercial companies and nations alike. Figure 3: In April 2016, SpaceX’s Falcon 9 first stage landed on droneship aptly named “Of Course I Still Love You. View the landing on                    __________________________________________________________________________________                                                                    Gen . Mac Tech  Zone Space ship Structure __________________________________________________________________________________