Related by context. All words. (Click for frequent words.) 65 spacecraft orbiting 61 Odyssey orbiter 61 infrared telescopes 60 Mars landers 60 laser altimeter 60 Mars Reconnaissance Orbiter MRO 60 satellites orbiting 60 orbiting spacecraft 59 NASA Mars Odyssey 58 orbiting Mars 58 irregularly shaped asteroid 58 satellites orbiting Earth 58 occultations 57 Earth orbiting satellites 57 Lunar Reconnaissance Orbiter LRO 57 STEREO spacecraft 57 Mars orbiter 57 NASA Cassini spacecraft 57 Mars Odyssey spacecraft 57 flybys 57 Mars Odyssey 57 NASA EPOXI mission 57 NASA Cassini 56 situ measurements 56 Rosetta spacecraft 56 Cassini Huygens 56 satellites orbiting Mars 56 Context Camera 56 HRSC 56 Mars Reconnaissance Orbiter 56 orbiting telescopes 56 Nasa spacecraft 56 High Resolution Imaging 56 Rosetta orbiter 56 robotic rovers 56 NASA rovers 56 Orbiter MRO 56 radar altimeter 56 spaceborne 55 downlinks 55 NASA Odyssey orbiter 55 Spitzer infrared 55 gamma ray detectors 55 infrared spectrometers 55 microwave radiometers 55 radar altimeters 55 radiometers 55 Mars Odyssey orbiter 55 X ray telescopes 55 HiRISE camera 55 Ulysses spacecraft 55 spacecraft Cassini 55 Cassini flyby 55 Synthetic Aperture Radar SAR 55 Mars Orbiter Camera 55 Voyager spacecraft 55 Saturnian moon Titan 55 flyby 54 Nasa Mars Reconnaissance 54 spacecrafts 54 Opportunity rovers 54 electromagnetic signals 54 NASA Mars Reconnaissance 54 Mars Color Imager 54 Mars moon Phobos 54 geosynchronous satellites 54 spacecraft 54 Fermi telescope 54 ESO telescopes 54 flyby spacecraft 54 Comet Hartley 2 54 ESA ERS 54 telescopic camera 54 asteroid Steins 54 NASA MESSENGER spacecraft 54 unmanned probes 54 VIRTIS 54 TanDEM X 54 Solar Terrestrial Relations 54 flyby Cassini 54 Cassini orbiter 54 THEMIS satellites 54 orbiting Hubble Space Telescope 54 http:/www.nasa.gov/cassini 54 rovers Spirit 54 Cassini 54 Composite Infrared Spectrometer 53 Mars orbiting spacecraft 53 gradiometer 53 KODAK CCD Image Sensors 53 Iridium satellites 53 Martian rovers 53 orbiting observatories 53 Cassini spacecraft 53 satellites 53 WFC3 53 Climate Experiment GRACE 53 astronomical observations 53 IBEX spacecraft 53 APXS 53 rovers 53 orbiters 53 geostationary satellites 53 Express orbiter 53 Comet Hartley 53 spectral bands 53 ESA Envisat satellite 53 NASA Wilkinson Microwave 53 earth orbiting satellites 53 polar orbiting satellites 53 ESA Huygens probe 53 gamma ray observatories 52 SMOS 52 MARSIS 52 Advanced Microwave Scanning 52 orbiting Mars Odyssey 52 Envisat satellites 52 CALIPSO 52 Viking landers 52 X ray spectrometer 52 AERONET 52 Orbiter LRO 52 interplanetary spacecraft 52 WISE infrared 52 MARSIS radar 52 robotic explorers 52 geosynchronous orbits 52 fly bys 52 ray Space Telescope 52 telescopes 52 Mössbauer 52 Resolution Stereo Camera 52 crewed spacecraft 52 Moderate Resolution Imaging 52 radiosondes 52 Deep Impact comet 52 shepherding spacecraft 52 ion thrusters 52 lunar orbiters 52 HiRISE images 52 Jovian moons 52 Mars rovers Opportunity 52 retroreflector 52 Martian surface 52 infrared 52 polarimetric 52 thermal infrared 52 ESA ASI 52 Global Surveyor 52 ESA Planck 52 aboard ESA Envisat 52 dust devils 52 spectrographic 52 Saturn Cassini 52 orbital rendezvous 52 interferometric synthetic aperture radar 52 Mars rovers Spirit 52 TerraSAR X 52 X ray observatories 52 airglow 52 gamma ray spectrometer 52 NASA rovers Spirit 51 radar altimetry 51 synthetic aperture radars 51 hyper spectral 51 THEMIS spacecraft 51 Solar Dynamics Observatory 51 ENVISAT 51 ESA Huygens 51 fainter objects 51 HiRISE camera aboard 51 Science Experiment HiRISE 51 Kepler spacecraft 51 celestial observations 51 NASA Landsat 51 lunar orbits 51 NASA Lunar Reconnaissance 51 Venusian surface 51 Cassini Huygens spacecraft 51 Huygens Probe 51 ultraviolet spectrograph 51 Shuttle Radar Topography 51 NASA satellites orbiting 51 Mini Thermal Emission 51 Hubble Space Telescope HST 51 Huygens descent 51 asteroid Lutetia 51 Titan flybys 51 orbiting Saturn 51 rover Opportunity 51 robotic probes 51 CARTOSAT 2A 51 synthetic aperture radar 51 Synthetic Aperture Radar 51 Aerosonde aircraft 51 Mission SRTM 51 backscattered 51 gamma ray observatory 51 LRO spacecraft 51 lunar probes 51 comet flyby 51 millimeter wavelengths 51 LCROSS spacecraft 51 multispectral camera 51 Diviner Lunar Radiometer Experiment 51 NASA ICESat 51 infrared imagery 51 DISR 51 Mars rovers 51 infrared ultraviolet 51 lander 51 reconnaissance orbiter 51 Clementine spacecraft 51 NFIRE satellite 51 spectrometers 51 optical telescopes 51 UVIS 51 altimeters 50 Infrared Mapping Spectrometer VIMS 50 reconnaissance drones 50 orbiters landers 50 Landsat satellites 50 GALEX 50 infrared spectrometer 50 detect gamma rays 50 ESA Mars 50 GOES satellites 50 XMM Newton 50 Mars Global Surveyor 50 microscopic imager 50 Solar TErrestrial RElations Observatory 50 six wheeled rover 50 orbiter Mars Odyssey 50 Dynamics Observatory 50 polarimetry 50 NFIRE 50 Messenger spacecraft 50 NASA Stardust spacecraft 50 GRACE satellites 50 gendarme helicopter 50 Mars Pathfinder lander 50 Earth orbiting spacecraft 50 electro optical sensors 50 UVOT 50 martian surface 50 thruster firings 50 spectroscopic measurements 50 Planck satellite 50 HARPS spectrograph 50 spectrographs 50 neutron detector 50 visit http:/saturn.jpl.nasa.gov 50 IKONOS 50 submillimeter wavelength 50 dropsondes 50 Telescope BAT 50 ALMA antennas 50 LADEE 50 Faint Object 50 C1XS 50 Galileo spacecraft 50 lunar missions 50 LRO 50 Mars CRISM 50 HIRES spectrometer 50 Infrared Pathfinder Satellite 50 Marsis 50 hexagonal mirrors 50 EPOXI spacecraft 50 Voyager probes 50 NASA Stratospheric Observatory 50 Titan flyby 50 orbiter lander 50 Pancam 50 Alpha Particle 50 GOSAT 50 Mars Orbiter 50 hyperspectral imager 50 spacecraft orbited 50 HiRISE 50 infrared astronomy 50 geostationary orbits 50 NEOSSat 50 detect gravitational waves 50 Descent Imager Spectral Radiometer 50 Deep Impact flyby spacecraft 50 X ray Telescope XRT 50 Hubble observations 50 probe Huygens 50 radiometer 50 LEO satellites 49 http:/saturn.jpl.nasa.gov 49 Stardust spacecraft 49 Global Positioning Satellites 49 UAVSAR 49 frequency VLF 49 Aqua satellite 49 Galileo satellites 49 synthetic aperture 49 microshutters 49 Huygens spacecraft 49 Microscopic Imager 49 interstellar particles 49 robotic explorer 49 Ultraviolet Optical Telescope 49 TerraSAR X satellite 49 planetary Transits 49 dropsonde 49 infrared imager 49 infrared observatory 49 zap boulders 49 SINFONI 49 Cloud Aerosol Lidar 49 orbiter 49 NASA Lunar Prospector 49 unpiloted aircraft 49 Gamma ray 49 LROC 49 rover panoramic 49 radar lidar 49 TRMM satellite 49 submillimeter 49 penetrating radar 49 SpaceShip Two 49 Lunar Reconnaissance Orbiter Camera 49 GloPac 49 imaging spectrometer 49 COROT 49 Uninhabited Aerial Vehicle 49 Comet Churyumov Gerasimenko 49 orbiting gamma ray 49 Proba 2 49 lunar surface 49 Foton M3 49 astrophysical phenomena 49 WISE spacecraft 49 Mars Opportunity rover 49 submillimetre 49 ICESat 49 Atlantis undocks 49 exoplanets planets 49 interferometers 49 spy satellites 49 Comet #P/Churyumov-Gerasimenko 49 Saturn moon 49 Multi Object Spectrometer 49 Spectrograph 49 orbiter robotic arm 49 Keck telescopes 49 geosynchronous satellite 49 constellations Cygnus 49 ESA XMM Newton 49 amateur astronomers peering 49 towering thunderheads 49 moonquakes 49 ESA Envisat 49 Huygens 49 Mission TRMM satellite 49 electric ion propulsion 49 Heliospheric Observatory SOHO 49 ESA Integral 49 MESSENGER MErcury Surface 49 neutron spectrometer 49 microgravity experiments 49 Milstar II 49 NASAs 49 Saturn outermost moon 49 STSS satellites 49 robotic spacecraft 49 gravitational microlensing 49 Observatory SDO 49 WMAP satellite 49 Burst Alert 49 NASA Voyager spacecraft 49 ROSAT 49 Wilkinson Microwave Anisotropy Probe 49 GMTI 49 NASA LCROSS 49 neutrino particles 49 Envisat satellite 49 planetary missions 49 panchromatic camera 49 Suzaku X ray 49 wheeled rovers 49 LEOP 48 Unmanned drones 48 Ocean Salinity 48 stellar occultations 48 Enceladus flyby 48 satellite altimeters 48 radio occultation 48 X ray observatory 48 Reflection Radiometer 48 Relations Observatory STEREO 48 Enceladus flybys 48 robotic landers 48 multispectral 48 twin rover Opportunity 48 Predator drone flies 48 IceBridge 48 unmanned reconnaissance aircraft 48 NASA THEMIS 48 Mossbauer spectrometer 48 infrared cameras 48 Aerojet propulsion 48 radiometry 48 Resolution Imaging 48 Array ALMA 48 Cassini flybys 48 orbiting satellites 48 MESSENGER 48 infrared telescope 48 submillimeter wavelengths 48 OMEGA instrument 48 interferometric 48 NASA Kepler telescope 48 Infrared Astronomy 48 Orbiting spacecraft 48 Airborne Topographic Mapper 48 Amateur astronomers 48 THEMIS 48 Lunar Reconnaissance Orbiter 48 CloudSat 48 RXTE 48 martian 48 scatterometer 48 Opportunity rover 48 Jupiter flyby 48 Cosmic rays 48 Martian polar 48 N. Rathnasree 48 Thermal Emission Imaging 48 pointings 48 parabolic microphones 48 Saturn moon Enceladus 48 SOHO spacecraft 48 hyperspectral sensors 48 NAVSTAR Global Positioning System 48 solar corona 48 Infrared Astronomy SOFIA 48 orbiter Cassini 48 Solar Dynamics 48 telescopic observations 48 satellite IKONOS 48 NASA twin rovers 48 MESSENGER spacecraft 48 SkyRouter 48 Explorer WISE 48 Robotic Arm Camera 48 Martian lander 48 observatories 48 optical wavelengths 48 C NOFS 48 orbited Jupiter 48 remote sensing satellites 48 CloudSat radar 48 Chajnantor plateau 48 geo synchronous 48 asteroid Itokawa 48 Ikonos 48 HiRISE image 48 STSS Demo 48 X ray Spectrometer 48 SCIAMACHY 48 reconnaissance satellites 48 RapidEye constellation 48 transiting exoplanets 48 Saturn moon Mimas 48 Impact Probe MIP 48 microlensing events 48 EPOXI mission 48 Neutron Spectrometer 48 Samuel Oschin Telescope 48 laser altimetry 48 CoRoT satellite 48 Global Surveyor spacecraft 48 Nasa Kepler 48 GOCE satellite 48 Apollo missions 48 LCROSS mission 48 exoplanetary 48 gravitational lenses 48 Mars Orbiter Laser Altimeter 48 Cartosat 2B 48 Infrared Array Camera 48 KBOs 48 Earth magnetotail 48 STEREO satellites 48 Herschel Planck 48 asteroid Vesta 48 Nasa Mars Odyssey 48 NASA Tropical Rainfall 48 Stardust NExT mission 48 Martian winters 48 inch Samuel Oschin 48 NASA Kepler 48 NASA Cassini orbiter 48 robot rovers 48 stationary lander 48 highly elliptical orbits 48 photometry 48 ecliptic plane 47 Terrain Mapping Camera 47 Space ENvironment GEochemistry 47 coronal holes 47 dimensional atlas 47 Phoenix lander 47 Planck telescope 47 interferograms 47 deorbiting 47 scramjet propulsion 47 Martian landscape 47 DigitalGlobe WorldView 47 mere fly bys 47 Phoenix Mars Lander 47 EPOCh 47 spacecraft flyby 47 Cosmic Origins Spectrograph 47 orbit GEO 47 polar orbiting 47 LORRI 47 Imaging Spectroradiometer MODIS instrument 47 waning gibbous 47 Shenzhou VI craft 47 transoceanic flights 47 infra red imaging 47 Huygens lander 47 Canadian Julie Payette 47 Metop 47 Landsat satellite 47 hyperspectral 47 neutrino detectors 47 NASA Solar Terrestrial 47 SeaWiFS 47 Philae lander 47 gamma rays emitted 47 emergency locator transmitters 47 waxing crescent 47 distant supernovae 47 earthlike planets 47 exoplanets orbiting 47 asteroid Eros 47 spacecraft Chandrayaan 1 47 GPS satellites 47 laser designators 47 synchrotron x ray 47 Cherenkov radiation 47 GROND 47 ultraviolet imaging spectrograph 47 gyro stabilized 47 electro optical sensor 47 orbiting 47 cosmological distances 47 infra red sensors 47 NuSTAR 47 Predator drones 47 moons orbiting Pluto 47 sondes 47 Huygens mission 47 Foton M2 47 Ultraviolet Imaging Spectrograph UVIS 47 Venusian atmosphere 47 lander rover 47 New Horizons spacecraft 47 Epsilon Aurigae 47 CRISM 47 MetOp 47 Reconnaissance Orbiter 47 Skynet 5C 47 O OREOS 47 Mini TES 47 multispectral imagery 47 Epoxi 47 ExoMars rover 47 Infrared Thermal Imaging Spectrometer 47 wispy cirrus clouds 47 Saturn moons 47 infrared camera 47 Sounder AIRS instrument 47 Envisat ASAR 47 NASA Atmospheric Infrared 47 moon Enceladus 47 moons Phobos 47 geo stationary orbit 47 Starfire Optical Range 47 Remote sensing 47 comet Churyumov Gerasimenko 47 Phased array 47 Mars Lander 47 stellar occultation 47 Rosetta comet 47 AIRS instrument 47 ARGUS IS 47 Churyumov Gerasimenko 47 Gusev crater 47 hypersonic speeds 47 ExoMars Trace Gas 47 Red Planet 47 infrasonic 47 planet magnetosphere 47 photometer 47 ESA SMART 47 satellite altimetry 47 NEAs 47 Advanced Synthetic Aperture 47 Near Infrared Camera 47 Shepherding Spacecraft 47 X ray photons 47 Comet Lulin 47 distant quasars 47 SMOS Soil Moisture 47 Atmospheric Infrared Sounder 47 thermal emission spectrometer 47 Opportunity Mars rovers 47 thin crescent 47 NASA Mars rovers 47 starquakes 47 Lunar Orbiter Laser Altimeter 47 Herschel Space 47 comet Lulin 47 infra red cameras 47 Orbiters 47 earthshine 47 NASA Gamma ray 47 VLBA observations 47 twin rovers Spirit 47 altimetry 47 robotic geologists 47 mothership WhiteKnightTwo 47 Herbig Haro 47 Satellites GOES 47 geomagnetic activity 47 Galactic cosmic rays 47 MER rovers 47 XMM Newton X ray 47 QWIP 47 drones 47 reconnaissance missions 47 HAMSAT 47 NASA rover Spirit 47 Flyby 47 radial velocity technique 47 LOFAR 47 Martian rover 47 Eagle lunar lander 47 GEO satellites 47 takeoffs landings 47 aerial reconnaissance 47 WGS satellites 47 interstellar boundary 47 ISS crewmembers 46 Mastcam 46 Ranging MESSENGER spacecraft 46 electro optic sensors 46 Sensing Satellite LCROSS 46 NASA Far Ultraviolet 46 Mars Pathfinder 46 photomultiplier tube 46 astronomical observatories 46 rover 46 slender crescent 46 odometry 46 astrometry 46 radars telemetry 46 magnetotail 46 NASA CloudSat 46 Earth orbit LEO 46 Wilkinson Microwave Probe 46 exhaust plume 46 comet particles 46 Martian terrain 46 interstellar dust samples 46 Surveillance System STSS 46 WISE telescope 46 lidar instrument 46 Saturnian moon 46 Fomalhaut b 46 scramjets 46 Landsat images 46 remotely sensed 46 expertise ICx pioneers 46 MG J# +# 46 NEAR Shoemaker 46 AATSR 46 gamma ray flashes 46 twin rover Spirit 46 Michibiki 46 Optech ALTM 46 airspeed indicator 46 Unmanned Aerial Vehicles UAVs 46 microwave radiometer 46 MQ 8B 46 scanning electron microscopes 46 GIOVE B 46 NASA Mars Orbiter 46 arcminutes 46 gamma ray photon 46 Great Observatories 46 Yinghuo 1 46 QuickBird 46 Wallops Island Va. 46 faint galaxies 46 Jupiter Uranus 46 spatially resolved 46 Spitzer Infrared Array 46 unmanned drones 46 GeneSat 46 X ray telescope 46 ScanEagle 46 TEGA ovens 46 SIM PlanetQuest 46 Planetary Fourier Spectrometer PFS 46 OSIRIS REx 46 Hubble orbits 46 RHESSI 46 Galilean moons 46 Atacama Large Millimeter submillimeter 46 SPICAM 46 coronagraph 46 wavebands 46 ionospheric 46 innermost planet 46 extragalactic 46 HARPS instrument 46 SBIRS HEO 46 USVs 46 Shenzhou capsules 46 cosmic microwave radiation 46 Earth orbiting LEO 46 alien civilizations 46 Forward Looking Infrared FLIR 46 Reflection Radiometer ASTER 46 Multi Object Spectrograph 46 robotic telescopes 46 ESO Paranal Observatory 46 Lunar Laser Ranging 46 OGLE TR #b 46 INSAT satellite 46 Aerosol Polarimetry Sensor 46 NASA Kepler spacecraft 46 Ranging spacecraft 46 planetary flybys 46 Infrared Astronomical Satellite 46 infrared detectors 46 infrared wavelengths 46 hypersonic flight 46 unmanned aerial vehicles 46 Hubble Space 46 Saturnian moons 46 telemetry instrumentation 46 orbiting telescope 46 Meridiani plains 46 Interior Laboratory GRAIL 46 Hubble Space Telescope 46 bolometers 46 Opportunity Mars rover 46 infrared sensors 46 VISTA telescope 46 SBSS satellite 46 laser designator 46 Kepler telescope 46 SMOS mission 46 Globalstar constellation 46 faraway galaxies 46 Shallow Subsurface Radar 46 telescope 46 Adaptive optics 46 Comet 9P/Tempel 1 46 Viking Orbiter 46 Cosmic Origins Spectrograph COS 46 Interferometer VLTI 46 echo sounders 46 Evolution Explorer 46 Orionid meteors 46 FLIR Forward Looking 46 radial velocity 46 unmanned Predator spy 46 Planck spacecraft 46 Comet McNaught 46 GigaGalaxy Zoom 46 discover Fomalhaut 46 auroral activity 46 remote sensing instruments 46 eclipsing binaries 46 lightwaves 46 interplanetary probes 46 Mars Climate Sounder 46 lunar equator 46 Climate Experiment SORCE 46 Anisotropy Probe WMAP 46 meteorological satellites 46 astrometric 45 LOFAR telescope 45 polar vortex 45 prograde 45 AMIE camera 45 omni directional microphones 45 UVIS instrument 45 TDRSS 45 highly elliptical orbit 45 Epsilon Eridani 45 GOES O 45 Planetary Transits 45 Comet Halley 45 Inertial Navigation Systems 45 Kepler Mission 45 postflight 45 CALIPSO satellites 45 Apollo lunar landings 45 comet Hartley 2 45 NEXRAD 45 Light Detection 45 cosmic ray 45 X ray pulses 45 datalink 45 Cartosat 2A 45 star IM Pegasi 45 KAGUYA 45 Nasa Deep Impact 45 geosynchronous 45 deformable mirrors 45 GOCE 45 lunar poles 45 infrared interferometry 45 Convection Rotation 45 kg payload 45 Manned missions 45 infra red 45 Tropical Rainfall Measuring 45 Area Telescope LAT 45 aerial surveillance 45 X ray afterglow 45 hatches swung 45 entire Milstar constellation 45 satellite RISAT 45 Viking orbiters 45 gamma ray spectrometry 45 impactor spacecraft 45 ultrashort pulses 45 Cosmic ray 45 Herschel telescope 45 Huygens probe 45 long baseline interferometry 45 gamma ray emission 45 GPS IIF satellites 45 hubble 45 Cassini Huygens Mission 45 datalinks 45 e MERLIN 45 Quadrantid meteor shower 45 Foton spacecraft 45 Spitzer infrared telescope 45 SpaceWeather.com 45 CBERS 2B 45 spectrometer 45 VLTI 45 lunar landers 45 Lightning flickered 45 ranging LIDAR 45 equatorial orbit 45 multispectral imager 45 hypersonic jet 45 Elevation Satellite 45 Ionospheric Sounding 45 Helicopters thumped 45 Earthlike planets 45 NIRSpec 45 Mars lander 45 Diviner 45 instrument calibrations 45 planetary transits 45 Orbital Express 45 interferometer 45 THEMIS probes 45 APEX telescope 45 UKIRT 45 Resolution Instrument 45 orbiting Cassini spacecraft 45 Kuiper Belt Objects 45 FORCAST 45 SIRTF 45 periodic dimming 45 surveillance drones 45 Total Ozone Mapping 45 LCROSS Lunar Crater Observation 45 downlinked 45 NASA Spirit rover 45 Atmospheric Infrared Sounder AIRS 45 orbital solitude 45 infrared spectra 45 ferry SpaceShipTwo 45 hydrogen maser 45 unmanned airships 45 panchromatic 45 Quickbird 45 Cosmic Radiation 45 Viking Lander 45 Nexrad 45 CoMP 45 velocity vector 45 Digitized Sky Survey 45 Very Large Array 45 Optical Spectroscopic 45 comet #P/Churyumov-Gerasimenko 45 jovian 45 elliptical orbits 45 Martian dust 45 exo planets 45 lightweight synthetic aperture 45 Fermi Gamma ray 45 observing satellites 45 Helix Nebula 45 interstellar distances 45 Galilean satellites 45 pitot static 45 multiband imaging photometer 45 orbiting Chandra 45 drone aircraft 45 laser beams 45 NASA STEREO 45 HARPS spectrograph attached 45 AVHRR 45 PASSUR radar 45 DMSP F# 45 aerosol measurements 45 infrared sensing 45 THEMIS Images 45 SECCHI 45 martian soil 45 noctilucent 45 Earth ionosphere 45 linearly polarized 45 IR LEDs 45 infared 45 polar orbit 45 neutral mass spectrometer 45 comets asteroids 45 gamma ray flares 45 AMSR E 45 #x magnification [001] 45 starshade 45 ultrahigh resolution 45 satellite downlinks 45 interacting galaxies 45 Jupiter Ganymede 45 Program DMSP 45 breathing supersonic combustion 45 comet nuclei 45 Chandra X ray 45 Ocean Salinity SMOS 45 Martian dust devils 45 closest flyby 45 Geminga 45 TDRS satellites 45 temperature barometric pressure 45 extraterrestrial civilizations 45 diffuse aurora 45 Operation IceBridge 45 smallest exoplanet 45 theodolites 45 Cydonia region 45 shortwave infrared 45 Ground penetrating radar 45 Kepler Space Telescope 45 Astrosat 45 protons collide 45 Lunar Orbiter 45 quadrocopter 45 VIRTIS instrument 45 remote sensing 45 airborne reconnaissance 45 Muchachos Observatory 45 Martian craters 45 durable twin rovers 45 Constellation Observing 45 ringed planet 45 Hubble Near Infrared 45 Saturnian system 45 Ares IX rocket 45 passive sonar 45 modified Boeing #SP 45 Predator unmanned 45 DMSP satellites 45 hyperspectral imaging 45 Orbiter spacecraft 45 GNSS receivers 45 lunar craters 45 azimuthal 45 STEREO 45 telemeter 45 extrasolar planets orbiting 45 spectroscopic analysis 45 barometric altimeter 45 Unmanned aircraft 45 infrared wavelength 44 ion propulsion 44 compass headings 44 martian landscape 44 orbiting Hubble telescope