Space Systems Fundamentals Instructor
Space Systems Fundamentals
February 5-8, 2018 Albuquerque, New Mexico $2190 (9:00am - 4:30pm) Summary "Register 3 or More & Receive $10000 each This four-day course provides an overview of the Off The Course Tuition." fundamentals of concepts and technologies of modern spacecraft systems design. Satellite system and mission design is an essentially interdisciplinary sport that combines engineering, science, and external phenomena. We will concentrate on scientific and engineering foundations of spacecraft systems and Course Outline interactions among various subsystems. Examples 1. Space Missions And Applications. Science, show how to quantitatively estimate various mission exploration, commercial, national security. Customers. elements (such as velocity increments) and conditions 2. Space Environment And Spacecraft (equilibrium temperature) and how to size major Interaction. Universe, galaxy, solar system. spacecraft subsystems (propellant, antennas, Coordinate systems. Time. Solar cycle. Plasma. transmitters, solar arrays, batteries). Real examples Geomagnetic field. Atmosphere, ionosphere, are used to permit an understanding of the systems magnetosphere. Atmospheric drag. Atomic oxygen. selection and trade-off issues in the design process. Radiation belts and shielding. The fundamentals of subsystem technologies provide 3. Orbital Mechanics And Mission Design. an indispensable basis for system engineering. The Motion in gravitational field. Elliptic orbit. Classical orbit basic nomenclature, vocabulary, and concepts will elements. Two-line element format. Hohmann transfer. make it possible to converse with understanding with Delta-V requirements. Launch sites. Launch to subsystem specialists. geostationary orbit. Orbit perturbations. Key orbits: The course is designed for engineers and managers geostationary, sun-synchronous, Molniya. who are involved in planning, designing, building, 4. Space Mission Geometry. Satellite horizon, launching, and operating space systems and ground track, swath. Repeating orbits. spacecraft subsystems and components. The 5. Spacecraft And Mission Design Overview. extensive set of course notes provide a concise Mission design basics. Life cycle of the mission. reference for understanding, designing, and operating Reviews. Requirements. Technology readiness levels. modern spacecraft. The course will appeal to Systems engineering. engineers and managers of diverse background and 6. Mission Support. Ground stations. Deep varying levels of experience. Space Network (DSN). STDN. SGLS. Space Laser Ranging (SLR). TDRSS. 7. Attitude Determination And Control. Instructor Spacecraft attitude. Angular momentum. Dr. Mike Gruntman is Professor of Astronautics at Environmental disturbance torques. Attitude sensors. the University of Southern California. He Attitude control techniques (configurations). Spin axis is a specialist in astronautics, space precession. Reaction wheel analysis. physics, space technology, rocketry, 8. Spacecraft Propulsion. Propulsion requirements. sensors and instrumentation. Gruntman Fundamentals of propulsion: thrust, specific impulse, participates in theoretical and total impulse. Rocket dynamics: rocket equation. experimental programs in space science Staging. Nozzles. Liquid propulsion systems. Solid and space technology, including space propulsion systems. Thrust vector control. Electric missions. He authored and co-authored nearly 300 propulsion. publications. 9. Launch Systems. Launch issues. Atlas and Delta launch families. Acoustic environment. Launch What You Will Learn system example: Delta II. 10. Space Communications. Communications • Common space mission and spacecraft bus basics. Electromagnetic waves. Decibel language. configurations, requirements, and constraints. Antennas. Antenna gain. TWTA and SSA. Noise. Bit • Common orbits. rate. Communication link design. Modulation • Fundamentals of spacecraft subsystems and their techniques. Bit error rate. interactions. 11. Spacecraft Power Systems. Spacecraft power • How to calculate velocity increments for typical system elements. Orbital effects. Photovoltaic systems orbital maneuvers. (solar cells and arrays). Radioisotope thermal generators (RTG). Batteries. Sizing power systems. • How to calculate required amount of propellant. 12. Thermal Control. Environmental loads. • How to design communications link. Blackbody concept. Planck and Stefan-Boltzmann • How to size solar arrays and batteries. laws. Passive thermal control. Coatings. Active thermal • How to determine spacecraft temperature. control. Heat pipes.
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Mike Gruntman Space Systems Fundamentals – Part 01. Course. Space Missions.
Space Systems Fundamentals
SpaceFundamentals Systems Fundamentals Systems Mike Gruntman - Space 2017
Sample 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 1/24 Mike Gruntman Space Systems Fundamentals – Part 01. Course. Space Missions.
Space Systems Fundamentals
Four-day course
• Section 01 – 50–70 min break 10–15 min • Section 02 Fundamentals – 50–70 min break 10–15 min • Section 03 – 50–70 min SystemsLunch break • Section 04 – 50–70 min Space break 10–15 min - • Section 05 – 50–70 min break 10–15 min • Section 06 – 50–70 min Sample 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 3/24 Mike Gruntman Space Systems Fundamentals – Part 01. Course. Space Missions.
Space Systems Fundamentals
Day 1 Day 2 • Part 01 • Part 07 Organization and Scope of the Orbital Mechanics III Course. Space Missions and Applications. • Part 08 Fundamentals • Part 02 Space Mission Geometry Universe, Galaxy, Solar System • Part 09 • Part 03 Operations. Reliability. Space Environment I Systems
• Part 04 • Part 10 Space Environment II Space Mission Overview. System Engineering. • Part 05 Space Orbital- Mechanics I • Part 11 ADC I • Part 06 Orbital Mechanics II • Part 12 Sample ADC II 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 4/24 Mike Gruntman Space Systems Fundamentals – Part 01. Course. Space Missions.
Space Systems Fundamentals
Day 3 Day 4 • Part 13 • Part 19 ADC III Communications I • Part 14 • Part 20 Fundamentals Propulsion I Communications II • Part 15 • Part 21 Propulsion II Electric Power I Systems • Part 16 • Part 22 Propulsion III Electric Power II • Part 17 Space • Part 23 Launch- Systems I Thermal Control l • Part 18 • Part 24 Launch Systems II Thermal Control II Sample 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 5/24 Mike Gruntman Space Systems Fundamentals – Part 01. Course. Space Missions.
Global Space American economy, infrastructure, and national security depend on satellites more than those of any other nation. Global space 2005 $189 B Europe 2015 – $8.2 B Government space $76.5B 2006 $219 B ESA (Eur. Sp. Ag.) $ 4.9 B in 2015 2007 $236 B United States $44.6 B 2008 $248 B European Union $ 0.1 B Europe $ 8.3 B 2009 $259 B France $ 1.4 B 2010 $275 B EUMETSAT $ 0.4 B FundamentalsBrazil $ 0.1 B 2011 $290 B Germany $ 0.6 B Canada $ 0.4 B 2012 $302 B Italy $ 0.5 B China (PRC) $ 4.2 B 2013 $314 B Spain $ 0.2 B 2014 $329 B India $ 0.9 B United Kingdom $ 0.1 B 2015 $323 B Israel $ 0.05 B Based on The Space Report 2016, The Space Report 2014, Systems Japan $ 2.7 B 2016, Space Foundation Space Foundation Russia $ 3.0 B Commitment (or lack thereof) to space South Korea $ 0.6 B Only France (andSpace the old Soviet Union in the past) a few countries $ 0.1 B each approaches the- U.S. space expenditures in terms of the many countries ≤ $0.01B ea. fraction of the gross domestic product (GDP). Most other industrialized countries (Europe and Japan) spend in non-U.S. military $ 10.6 B space, as fraction of GDP, four to six times less than the Based on The Space Report 2014, 2016, Space Foundation SampleUnited States. — M. Gruntman, Blazing the Trail, 2004 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 19/24 Mike Gruntman Space Systems Fundamentals – Part 02. Universe. … Coordinate systems
Inertial Systems of Coordinates Fundamentals
Systems
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Sample 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 17/25 Mike Gruntman Space Systems Fundamentals – Part 03. Space Environment I
• The region beyond the Magnetosphere ionosphere is called the magnetosphere. • In this region, the Earth’s magnetic field dominates physical processes and largely determines its Fundamentals structure. • The highly supersonic solar wind flow impinges on the magnetosphere and Systems forms a bow shock. • Inside the magnetopause, Space energetic charged- Earth magnetic dipole tilted by ~ 11 particles are “trapped” with respect to the earth spin axis. by the magnetic field (ions gyrate around The magnetosphere is bounded from interplanetary space by a current magnetic lines). layer, called the magnetopause (at ~10 R in the sunward direction). Sample E 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 15/18 Mike Gruntman Space Systems Fundamentals – Part 03. Space Environment I
Radiation belts Trapped Energetic Particles • During magnetospheric disturbances, strong precipitation of these ions to lower altitudes may occur in polar regions which produces Fundamentals spectacular aurorae. • Anisotropy of energetic particle velocities is often described through Systems the pitch-angle distribution Trapped ions gyrate around magnetic field lines • It is usually assumed while moving back and forth from one polar that spacecraft Space region to another (between the “mirror” points). bombarded by- energetic particles Example: 1-MeV electrons at 4 R from all directions E (isotropically) gyroradius – 6.3 km gyroperiod – 0.22 ms Sample mirror period – 0.27 sec drift period – 3.7 min 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 16/18 Mike Gruntman Space Systems Fundamentals – Part 04. Space Environment II
Protons 1-10 MeV LEO, MEO, GEO dose, SEE Trapped Energetic Electrons nuclear activation > 10 MeV LEO, MEO and Ions and Plasma dose (e.g., solar cells), SEE, DD (displ damage) > 50 MeV MEO, GEO nuclear activation Fundamentals Heavy ions >10 MeV MEO, GEO SEE
Electrons 0.1-1 MeV MEO, GEO internal charging Systems dose > 1 MeV LEO, MEO, GEO internal charging doseSpace Plasma 30eV – -LEO, MEO, GEO 100keV surface charging
dose J. E. Mazur, J. Fennell, T. Guild, T. P. O’Brien Tutorial on Actual Space Environmental Sample Hazards for Space Systems, AGU, 2013 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 9/24 Mike Gruntman Space Systems Fundamentals – Part 04. Space Environment II As of January 2013 Space Sat catal- decay- in Monthly Number of Cataloged oged ed orbit Debris Objects in Earth Orbit by Object Type FY-1C 3378 302 3076 Cosmos 1603 261 1342 2251 Iridium 598 119 479 33 Fundamentals Orbital Debris Quarterly News , v.17, is.1, p.8, 2013
Figure from Orbital Debris Systems Quarterly News (NASA), v. 20, issue 1-2, p.14, April 2016. Figure augmentation by Mike- GruntmanSpace
Summary of all objects in Earth orbit officially cataloged by the U.S. Space Surveillance Network. “Fragmentation debris” includes satellite breakup debris and anomalous event debris, while “mission- Samplerelated debris” includes all objects dispensed, separated, or released as part of the planned mission. 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 18/24 Mike Gruntman Space Systems Fundamentals – Part 05. Orbital Mechanics I
Earth Oblateness
Geoid = equipotential surface of the gravity field most closely approximating mean sea level
Especially important: 2 Fundamentals J2 and J2 (or J22)
nnn GM a a Vr,, 1 JPn ncos J nm P nmcoscos m nm rrr nnm221
Accurate geoid model Systemsequatoria l radius: Re = 6378.14 km produced by the Gravity field and steady-state Ocean polar radius: Rp = 6356.8 km Circulation Explorer (GOCE) volumetric radius: Rv = 6371.0 km mission. The deviations in volumetric mean radius is the radius of a sphere height (–100 m to +100 m) with the same volume Spacefrom an ellipsoid are - exaggerated 10,000 times in the image. The blue colors orbit altitude commonly referred to represent low values and the the difference between the orbit reds/yellows represent high radius and the equatorial radius: values. h = R – R Sample Credit: ESA/HPF/DLR and NAS e 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 13/20 Mike Gruntman Space Systems Fundamentals – Part 05. Orbital Mechanics I
Classical Orbital Elements • a semi-major axis • e eccentricity • i Fundamentalsinclination • right ascension Systems of ascending node • Space argument of - perigee • true anomaly Sample 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 15/20 Mike Gruntman Space Systems Fundamentals – Part 06. Orbital Mechanics II Main Launching Sites
Fundamentals
Systems
1) Cape Canaveral, Florida 10) Kourou, French Guiana 2) Vandenberg Air ForceSpace Base, California 11) Tanegashima Island 3) Wallops Island- 12) Sriharikota Space Center, Tamil Nadu 4) Kwajalein Atoll 13) Jiuquan Satellite Launch Center, Gobi Desert (1st) 5) Kodiak Island 14) Xichang Satellite Launch Center, Sichuan Province 6) Baikonur, or Tyuratam, Cosmodrome 15) Taiyuan (Wuzhai) Satellite Launch Center, Shanxi Province 7) Plesetsk Cosmodrome 16) Wenchang Satellite Launch Center, Hainan Province 8) Kapustin Yar 17) Yavne, Palmachim Air Force Base Sample9) Svobodny 18) Alcantara 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 16/91 Mike Gruntman Space Systems Fundamentals – Part 07. Orbital Mechanics III
Devised by the USSR to provide Molniya Orbit • features of a geosynchronous orbit • with better coverage of northern latitudes • USSR was largely a Northern country: latitude of Moscow = mid-Labrador, Hudson Bay typical Fundamentals latitude of Leningrad = hP = 500–1200 km southern tip of Greenland e = 0.71 – 0.74 • global coverage from an orbit without the large orbital plane change during launchSystems Tyuratam (Baikonur) – 4554’ N Plesetsk – 6248’ N Space 22 d 3 nJ 20- R 4 - 5 sin i = 0 dt 4 ae222 (1 ) Samplesin(i )= 4 5 i=63.4oo or i=116.6 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 12/22 Mike Gruntman Space Systems Fundamentals – Part 09. Operations. Reliability
Tracking and Data Relay Satellite System (TDRSS)
• Relay satellites in geosynchronous orbit • Eliminates the need for worldwide network • the first TDRS was Fundamentals launched in 1983 • operational satellites are separated by 135 of longitude • ground terminal at White Systems Sands • initially provided 80% coverage of satelliteSpace orbits • expanded to- 100% with the addition of the third location (satellite) and Sampleground terminal in Guam 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 11/18 Mike Gruntman Space Systems Fundamentals – Part 10. Mission Overview. System Engineering
Technology Readiness Levels – TRLs
TRL 9 TRL 5 Actual system “flight proven” Component and/or breadboard through successful mission validation in relevant environment operations TRL 4 TRL 8 ComponentFundamentals and/or breadboard Actual system completed and validation in laboratory environment “flight qualified” through test and TRL 3 demonstration (ground or flight) Analytical and experiment critical TRL 7 function and characteristic proof-of- Systemsconcept System prototype demonstration TRL 2 in a space environment Technology concept and/or TRL 6 Space application formulated System/subsystem- model or TRL 1 prototype demonstration in a Basic principles observed and relevant environment (ground or reported Samplespace) 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 13/20 Mike Gruntman Space Systems Fundamentals – Part 11. Spacecraft ADC I Earth Horizon Sensors – Scanning Sensors
Scanning Sensors • employ a spinning mirror or prism to focus a narrow pencil of light onto sensing element • sensing element is usually a bolometer Fundamentals • electronics in the sensor detect when the infrared (IR) signal from the Earth is first received or finally lost during each sweep of the scan cone Systems • horizon sensor detects not the first contact with land or ocean, but the point in the atmosphere at which the 16 radiation reaches a certain intensitySpace - Simple narrow field-of-view fixed • from the time between the arrival head sensor types (called pippers or of signal (AOS) and loss of signal horizon crossing indicators) are used (LOS) the Earth width is on spinning spacecraft Sampledetermined 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 20/26 Mike Gruntman Space Systems Fundamentals – Part 12. Spacecraft ADC II
Boeing (Hughes) 376 stowed (left) and deployed. Boeing (Hughes) Figure courtesy 376 Galaxy Dual Spin The Boeing Company • cylindrical solar array • spinning sensors (sun, earth, star, RF) Figure courtesy The Boeing Company • despun platform • speed and precession Fundamentals control • wobble and nutation (dampers) Systems • despin control
example: - Space DSCS II, TIROS, HS376, HS396 Sample 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 9/18 Mike Gruntman Space Systems Fundamentals – Part 13. Spacecraft ADC III
• 24 satellites in six orbit planes GPS Space Segment • 4 satellites in each orbit • 12-hour period 26,561.75 km circular orbits • inclination: 55 • longitude crossing at the equator kept fixed to within 2 by the GPS Control Segment Fundamentals • perturbations: atmospheric drag is insignificant lunar and solar gravitational pull can be significant solar radiation pressure can beSystems
significant Figures courtesy • precisely timed GPS signals are Crosslink transmitted at two L-band frequencies: 1.57542Space GHz and 1.2276 GHz- • frequencies are selected to minimize interference with radio astronomy bands Sample GPS IIA GPS IIR 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 17/20 Mike Gruntman Space Systems Fundamentals – Part 14. Spacecraft Propulsion I Rocket Equation Assume • no gravity • no drag Fundamentals•m = constant •FTH = constant
• tB is the burnout time • U is the rocket Systems speed
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U = ueq lnR ueq = ge ISP Sample 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 14/18 Mike Gruntman Space Systems Fundamentals – Part 15. Spacecraft Propulsion II
Converging-Diverging (De Laval) Nozzle
Area-velocity relation nozzle velocity M → 0 increases incompressible flow and Au = constant diffuser Fundamentalsvelocity 0 ≤ M <1 (subsonic flow) decreases an increase in velocity (du > 0) for a decrease in area (dA < 0) M >1 (supersonic flow) Systems an increase in velocity (du > 0) for an increase in area (dA > 0)
converging-divergingSpace nozzle (de Laval, or Laval- , nozzle) needed for transition from a subsonic flow to a Samplesupersonic flow 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 5/22 Mike Gruntman Space Systems Fundamentals – Part 15. Spacecraft Propulsion II
Regenerative Cooling – RL10
• Pratt & Whitney developed RL10 in 1959
• initially liquid H2 is heated to a temperature sufficiently higher above the critical temperature Fundamentals that it can be used to expand as a gas through the turbine
that drives the liquid H2 and O2 pumps. • capable of self-starting in Systems space (using pressure in hydrogen tanks) RL-10A • pressure is high no boiling- Spacetakes place • gaseous H2 is an excellent coolant high thermal conductivity Figure courtesy Sample Pratt & Whitney, A United Technologies Company 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 10/22 Mike Gruntman Space Systems Fundamentals – Part 16. Spacecraft Propulsion III Solid Rocket Motor. Example – Star 37 FM
The STAR 37FM rocket motor was developed and qualified for use as an apogee kick motor on FLTSATCOM and GPS Block IIR satellites and Fundamentals serves as the third stage on Boeing’s Delta II launch vehicle. The motor design features a titanium case, a 3D carbon-carbon throat, Systems and a carbon-phenolic exit cone. Maximum propellant weight is 2350 lb. The motor has beenSpace qualified for propellant- off-loading up to 2257 lb. Sample25 Star-37FM motors were flown from 1986-2012 Figures courtesy ATK Alliant Techsystems 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 5/20 Mike Gruntman Space Systems Fundamentals – Part 16. Spacecraft Propulsion III Magnetoplasmadynamic Thrusters (MPD) • steady-state MPD thrusters • discovered in 1960s Figure from • capable of producing continuous M. Andrenucci, 2010 thrust • require very high power Fundamentals • geometry similar to arcjet relatively low pressure high magnetic field higher electric field Systems • common propellants Flight model of “Micron” lithium thruster (left) and 500 kW lithium SF-MPD (right). hydrogen Gorshkov et al., IEPC, 2007 argon Space BPT-2000 Hall thruster by some MPDs - General Dynamics. Xenon are called xenon propellant; ISP = 1765 sec; power 1200– 2700 W. Hall thrusters lithium Photo courtesy of General Dynamics. Sample• no neutralizer required 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 18/20 Mike Gruntman Space Systems Fundamentals – Part 17. Launch Systems I
Delta IV – Dual-Payload Launch
Delta IV Heavy Dual-Manifest Spacecraft Deployment Sequence Fundamentals
Systems
Delta IV Heavy Dual-Payload Attach Fitting Space - Figures courtesy of United Launch Alliance, LLC.
Copyright © 20I0, 2007 United Launch Alliance, LLC. All rights Sample reserved. Used with permission. 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 20/22 Mike Gruntman Space Systems Fundamentals – Part 18. Launch Systems II Delta II Launch Typical Delta II 7925/7925H mission profile – GTO missions (ER launch site). Fundamentals
Systems
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SampleFigure courtesy The Boeing Company 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 14/20 Mike Gruntman Space Systems Fundamentals – Part 19. Spacecraft Communications I
Antenna and Gain Fundamentals
Antenna directive gain (directivity) Gd
G = G Systems P d Power gain = efficiency For a circular directive gain antenna diameter D Space - EIRP = Effective Isotropic Radiated Power 1.22 (radians) 70 deg Sample3dB D D 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 12/24 Mike Gruntman Space Systems Fundamentals – Part 20. Spacecraft Communications II Link Design (cont.)
• signal-to-noise ratio
Link Equation or Link Budget Fundamentals
• often convenient to use the decibelSystems language (addition and subtraction instead of multiplication and division)
E /N = P + Space L + G + L + L + G + L + 228.60 – 10 logT – 10 logR b 0 -t l,t t S a r l,r S
• losses (Llt, LS, La, Llr ) are < 1.0 (in numbers) and negative (in dB language) • antenna gains (G , G ) are >1.0 (in numbers) and positive (in dB language) Sample t r 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 11/22 Mike Gruntman Space Systems Fundamentals – Part 20. Spacecraft Communications II
Errors
• bandwidth required to transmit a given bit rate depends on modulation and the details of technique implementation (sideband truncation,…) • close-to-unity ratio of the data bit rate to the transmission bandwidth (bps/Hz) for Fundamentals QPSK • noise in the communications link results in errors • dependence (figure) for an idealized model and optimal RF filtering Systems characteristics • optimal filtering may not be achieved in practice for a variety of reasons, including manufacturingSpace imperfections • usually additional- implementation margin, a few decibels, to allow for possible imperfections in amplifiers and The selection of E /N would non-linearities in transmission path b 0 Sample depend on the desired BER 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 18/22 Mike Gruntman Space Systems Fundamentals – Part 21. Electric Power Systems I
Typical Sun tracking: solar panels rotate about Geostationary Orbit the axis normal to the orbital (equatorial) plane
eclipses two “seasons” (45 days each) centered around vernal (March 21) and autumnal (September 21) equinoxes the longest eclipses, of about 72 Fundamentals minutes, occur at equinoxes Systems
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Power out put of 1-m2 panel
for 0 = 20% and = 4%/yr Sample 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 8/20 Mike Gruntman Space Systems Fundamentals – Part 22. Electric Power Systems II
Nickel-Hydrogen Batteries Figure from B. N. Agrawal Design of Geosynchronous Spacecraft
• qualified for GEO • pressure vessel (Inconel) at 400–900 psi • negative electrode hydrogen Teflon-coated platinum (catalyst) plate • positive electrode sintered nickel • electrolyte aqueous solution of potassium hydroxide KOH (typically 31%
concentration by weight) Photos courtesy • separator EaglePicher Ni-H2 fuel cell asbestos specific energy 30-40 Wh/kg (nonwoven mat of energy density up to 60 Wh/l chrysotile asbestos nominal voltage 1.25 V/cell Samplefibers) or -zirconium Space Systems Fundamentals 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 10/20 Mike Gruntman Space Systems Fundamentals – Part 22. Electric Power Systems II
Fundamentals
Systems
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Sample 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 19/20 Mike Gruntman Space Systems Fundamentals – Part 23. Thermal Control I Main Environmental Thermal Loads
• environmental heating on orbit direct sunlight sunlight reflected off the Earth (especially for LEO) infrared (IR) energy Fundamentals emitted from the Earth (especially for LEO) • free molecular heating during launch or in exceptionally Systems low-altitude orbits Space Overall- thermal control of a satellite is usually achieved by balancing energy emitted by the spacecraft (as infrared radiation) energy dissipated by internal electrical components Sample energy absorbed from the environment 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 4/22 Mike Gruntman Space Systems Fundamentals – Part 23. Thermal Control I
Coatings
Fundamentals
Systems
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Sample 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 19/22 Mike Gruntman Space Systems Fundamentals – Part 24. Thermal Control II AEDC Mark 1 chamber 42-ft diameter 82-ft-tall chamber housed in a ten-story Test Facilities building; has 77 K capability Lockheed-Martin Delta horizontal 80-ft-long cylinder chamber; 36-ft in diameter; has 90 K capability JPL facility pressure 10–5–10–6 tor; solar simulation by an array of modules, each containing a 1-kW quartz-iodine lamp; color temperature 3000Fundamentals K blackbody Lockheed Martin's Dual Entry Large Thermal Altitude (DELTA) chamber in Sunnyvale, Calif. Photo courtesy Lockheed-Martin Systems
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From D. G. Gilmore Satellite Thermal Control Boeing’s thermal vacuum test Handbook chamber, El Segundo, Calif. SamplePhoto courtesy The Boeing Company 2006–2017 by Mike Gruntman Space Systems Fundamentals, 2017 20/20