Mission Design and Systems Engineering for Spacecraft

Chris Cully 2008 April 3 [email protected] Mission Design Jargon Please do mybesttokeep thejargonunder I’ll There isatremendous amountofjargon that you haven’t heard before! control. and acronymsin spacemissiondesign. stop me and askifIusea term Mission Design Today’s Lecture „ „ „ Case Study: the Themis mission actual spacecraft orpayload) including the Mission Elements (not Top Level: “ “ “ “ “ “ “ Process andtesting Ground Support Launcher Orbit Systems Engineering Sweden inSpace Objectives /Applications Mission Design Exploration „ „ Manned missions universe the system and Explore thesolar “ “ “ here Not really covered the sun,... comets, asteroids, Planets, moons, Robotic missions Cassini at Saturn Cassini at S Vision ofexploration ESA Mission Design Earth Observation „ „ „ „ „ Disaster monitoring Weather forecasts Land survey Resource monitoring Environmental monitoring “ “ “ “ “ “ “ Urban planning Vegetation and forests Water Marine Polar environmentsand ice Geophysics Climate andatmosphere Soil Moisture and OceanSalinity(SMOS) Mission Design Space Research „ „ „ „ Basic physics Plasma science Solar System Astronomy “ “ “ relativity tests e.g. general Atmosphere Upper Ionosphere and Northern lights COROT exoplanet finder Mission Design Commercial „ „ „ „ „ Internet via satellite Digital Radio VSAT (VerySmall ApertureTerminal) Digital multicasting/Video OnDemand Television broadcasting Mission Design Military „ „ „ Ban Treaty Organization) Treaty monitoring (eg. Comprehensive Test Civilian applications Purely military “ “ “ “ “ “ “ “ Space environment monitoring Navigation Reliable communications Reconnaissance ??? Ground targeting Anti-missile systems Surveillance American DMSP satellite American DMSP Mission Design Navigation „ „ „ Galileo GPS Global coverage “ “ “ “ “ “ as GPS Similar specifications Independence European civil version Accurate time Meter resolution system American military ESA’s Galileo Mission Design Sweden inSpace 2003 2001 2000 1998 1997 1995 1994 1992 1989 1986 SMART-1 Odin Munin Astrid 2 Sirius 3 Sirius 2 Commercial Telecom Astrid 1 (Bought inorbit) Sirius 1 Freja Scientific Tele X Viking Scientific Scientific Scientific ESA Technology test Scientific Scientific / Technical test Scientific / Commercial Telecom Commercial Telecom Commercial Telecom Kronogård 1962 Mission Design Swedish Spacecraft, Research Swedish Spacecraft, „ „ „ „ „ „ „ „ „ „ 2xBepiColombo (2012, Merkurius), 4xMMS (2013) (2005, Venus) Venus Express Express (2003,Mars), DoubleStar(2003), Rosetta(2004, komet), Saturnus/Titan), Nozomi (1998,Mars), 4xCluster(2000), Mars Mars-96 (1996, Mars),Equator-S (1997), Cassini (1997, (1996), heliosphere), Interball-tail (1995),Interball-aurora (1995),Polar Ulysses (1990, Phobos-1 (1988, Mars),Phobos-2(1988, (1978), Prognoz-7 Prognoz-8(1980), (1977), GEOS-2 Instruments on MicroLink (2009,technicaltest) Prisma (2008,technicaltest) moon) SMART-1 (2003,ESA, Odin (2001) Munin (2000) Astrid-2 (1998) Astrid-1 (1995) Freja (1992) Viking (1986) Chandrayaan (2007, månen), 3xSwarm (2009), ESRO-1A (1967), ESRO-1B(1967),ESRO-4 (1972),GEOS-1 Mission Design „ „ „ Systems Engineering Risks: assessed and managed (reduced) managed Risks: assessed and Subsystems need toallworktogether Key Issues: „ “ “ “ can’t physically reachit Once it’s launched, you interconnected tightly Subsystems are complex extremely System is mission design ingeneral. This is akeyconcept for thiscourse andfor Ariane-5 failure Mission Design Systems Engineering „ „ „ „ Identify and assess risks, work to minimize them Identify and assessrisks,workto minimize Process is iterative, notlinear General idea: the systemandprocesses Need toexamine “ “ “ “ “ “ “ Contingency plans Redundancy Single points of failure closure Assessment and Selection and implementation concepts Alternative design system goals quantify Identify and ƒ ƒ Æ Æ Requirements flow-down Trade studies as awhole Mission Design Mission elements „ „ Tomorrow: Today: “ “ “ “ “ “ Payload Satellite bus testing Process and Ground Support Launcher Orbit Mission Design Orbit fundamentals „ „ „ „ „ Variable speed Earth rotates underneath Some specialcases: inertial space Conic sectionorbits (closed=elliptical)in Idealized case:2-body pointmasses “ “ “ “ Fast atperiapsis Complicated ground tracks (prograde) East Best tolaunch circular, hyperbolic Polar, equatorial, Mission Design Classical orbital elements „ „ „ Where intheplane Plane Orientation: Ellipse size/shape: “ “ “ “ “ “ v:True anomaly ω:Argument ofperigee Ω:Right ascension of the node ascending i:Inclination e:Eccentricity a:Semimajor axis ƒ ƒ ƒ i >90retrograde i <90prograde (direct) Circle: e=0 Mission Design Perturbations „ „ „ „ 3-body perturbations (sun,moon, Jupiter) Radiation Pressure Atmospheric drag Non-spherical Earth “ “ Precession of line of apsides( Precession ofline Regression ofline of nodes( ƒ ƒ Zeroed for i=63.4 Prograde orbit Æ o westerly rotation (Molniya orbit) Ω ω ) ) Mission Design A fewspecialized Orbits „ „ „ Lissajous orbit Earth orbits objectives Requirements flowdown fromthemission “ “ “ “ Lagrange points HEO High EllipticalOrbit Orbit) LEO (Low-Earth Geostationary ƒ ƒ ƒ Molniya Sun-Synchronous GTO (GeosynchronousTransfer Orbit) Mission Design Transfer Orbits „ „ section orbits withanelliptic connect 2circular Hohmann transfer: Other transfers possible “ “ „ Need large thrusts efficient (least Usually themost plasma thrusters e.g. spiral orbitswith lowthrust from ΔV) Mission Design Interplanetary orbits Approximation: influence) patched conicsbetweenHillspheres(spheresof Mission Design Launchers „ „ Main factors to consider: vehicles available. launch Many expendible “ “ “ “ “ “ “ “ Availability and politics Vibration envelope Reliability Spacecraft size Spacecraft mass Orbit (ΔVrequirements) Cost mission design(”only” selection) Launcher designnotpart of Pegasus Proton Delta-II Mission Design Launchers „ „ „ available online sometimes User’s manuals launches to orbit Note that Sweden hasno Launcher alternatives “ “ “ “ “ “ “ “ and satellites/payloads Suborbital sounding rockets China India Japan USA Ukraine Russia Europe Soyuz user’s manual Soyuz user’s Fairing dimensions from Mission Design „ „ Inexpensive launchoptions Some alternatives: Common issue “ “ “ “ “ “ “ Test launches Russian ICBMs Hitchhiking Piggybacking address this ESA’s Vegadesignedto part oftotalbudget Launch costsignificant sats GEO for large Launchers often sized ƒ

ASAP-5

Launcher ”Kosmos” Piggybacked on Russian Swedish Astrid-2 Mission Design Ground Segment: General principle Mission Design Communications „ „ „ design parameters architectures and Large number of Ranging your treasure Your onlycontactwith “ “ “ “ “ “ of SMS!) (think ofthe average bitrate communication Content of Capacity (bitrate) Frequency carrier shift of Position andDoppler Telemetry Commanding missions Spain, usable fordeep space ESOC’s groundsation in Villafranca, Mission Design Mission Operations „ mission operations andgroundsupport Large partofmission costisrelatedto From Wertz Mission Design Testing „ „ „ „ „ „ Swedish facilities Magnetic, electrostatic tests Thermal / vacuum tests Shock tests Vibration tests piggyback) from the launcher (especially if requirements others arehard contractor, spacecraft prime Some tests are upto “ “ “ others Saab Ericssonspace Packforsk Munin Vibrational test tests, IRF Kiruna tests, IRF Thermal, outgassing space environment Vaccum chamberfor Themis magnetictests Mission Design ƒ ƒ Case Study: Themis „ observe aurora from ground during winter nights to simultaneously Alignment over Northern Hemisphere locations Plasma observations atmultiple substorms as processes known cause ofauroral Designed tostudy the “ “ 2 majormodels side at10-30 R Plasma disturbance thatoccurs onthenight E altitude (1R E =6378 km) Mission Design Themis Orbit Design „ „ „ „ highly elliptic Near-equatorial orbits, 5 Probes per year (13 months) of apsides rotates ~once In Earth-fixed frame, line multiples of 1day(1,2,4) All orbitsare integer “ “ “ at 20R Inclination: 9 deg Apogees: 3satsat10 R Perigees ~1000km E ,1 at30 E ,1 Mission Design Themis Launcher „ „ solid motor vehicle Delta-II launch directly to 3 directly to Assembly attached Probe Carrier “ “ “ mass:5 x130kg Spacecraft wet kick motor; 3 kick motor; Eliminates need for 3-stage, 9 strap-ons parking orbit reaches required rd rd stage stage Mission Design „ „ „ „ Themis Ground support tracking at ground stations tracking atground Orbit determination fromangle and Doppler Ground stations: S-band (2-4GHz)communications Mission Operations Center:Berkeley “ “ “ “ “ NORAD radar tracking backup Space Network NASA Deep NASA TDRS spacecraft, Contingency: Australia, Hawaii Secondary: UniversalSpaceNetwork (USN)at Main: Berkeley 400 kbit/sdown,1 up Mission Design THEMIS LAUNCH VIDEO Mission Design Today’s Lecture „ „ „ „ Ground Support: Launchers Orbits: System Engineering: “ “ “ “ “ “ well as for orbit determination link isvital for Communications command and control, as inexpensive ones from, to choosebut notmany launchers Many available changing orbits Velocity change forces orbits areperturbed by small Elliptic iterative, notlinear process is Engineering Need to examine the system and processes Δ V isthe fundamental parameter when as awhole Tomorrow: The spacecraft itself...

Chris Cully [email protected] Mission Design Mission Design ~70 km Mission Design