DawnDawn Journey totheAsteroid Frontier NASA’s DawnMission Lucy McFadden, Co-Investigator University ofMaryland College Park,MD January 12,2009 SBAG update DawnDawn 9 th Discovery Mission formation. planetary epoch of earliest survivors ofthe Ceres Vesta and are intact DawnDawn Dawn Exploresthe EarliestEpochs DawnDawn The AsteroidBelt DawnDawn Launched Sept.27, 2007 Solar array power(3AU):1.3kW Solar array Solar arraypower(1AU):10.3kW Wet mass:1240kg Dry mass:745kg Delta II 7925H-9.5 Delta II 5 DawnDawn Deep Space 1 Ion PropulsionSystem 50,000 hours. morethan propulsion. IPSwillthrustfor 8-Year Journeymadepossibleby ion DawnDawn DawnDawn Interplanetary Trajectory DawnDawn VIR Framing Camera – – – – and selected targets coverage ofsparseglobal grid High-spatial/high-spectral resolution near globalcoverage Spatially-averaged high-spectral angles fortopography Three clearmapsindifferent view three filters Near-global imagemosaics in Science Return- Data Sets 9 DawnDawn Gravity Detector GRaND – – – Ceres (and possibly Vesta) Ceres (andpossibly abundancemapfor Hydrogen (Ceres) and >10pixels (Vesta) greater than36pixels minor elementabundance with Maps ofmajorandselected (Ceres) degree 9(Vesta)and 5 to harmonic expansion Coefficients of spherical γ -ray/ Neutron Science Return- Data Sets FeO (wt.%) Thorium (ppm) 10 DawnDawn Registration of: (deconvolved) maps abundance Elemental maps composition Mineral Image mosaics Gravity map elevation grids Higher resolutionlocal model andgrids Topographic shape Integrated DataProducts Science Return Frame Reference Body-centered • • geological map Integrated Density model h v u o z u x V y u c O c x z W y c C S/ 11 DawnDawn Mission hasmotivated new knowldege DawnDawn Ceres’ Albedo features DawnDawn band at 280 nm appears to be confirmed. uncertainties new data poi U V s pectr um
n of C are ts New SpectralFeatures foundin f ere r ~<20 o m HS s. T Li etal.2008 %. he cr T/
The absorption AC osse S /SBC. s
are the T he
Ceres Rivkin et al.2006 DawnDawn Vesta • crust • indicates single pyroxene component that formed Dark greenishcolor indicatessinglepyroxene componentthatformed Bright yellowish color DawnDawn . Li etal.2007 Vesta albedoandcolor maps indicates mixing with several pyroxene or witholivineformed indicates mixing with severalpyroxeneor Hubble SpaceTelescope Binzel etal.1997 close to thesurface close to below the . 16 DawnDawn 2009. Watch NSPIRES for Participating Scientist Program early planning andreview. Monthly sciencetelecons, weekly tag-upand sequence beginning. Instrument Sequence Planningforobservations ofVesta Mars Flyby scheduled forFebruary17, 2009 Trajectory CorrectionManeuver #1(TCM-1)Nov.20,2008. June, 2009. Spacecraft coastingoptimally andscheduledtodosountil Instrument sequences arecompleteand tested. TCM-2 iscancelled. Trajectory refinementin progress. Mission Status 17 DawnDawn • • • • • Dawn forKids Ion Propulsionsimulation History andScienceofDawn Where isDawnnow?http://dawn.jpl.nasa.gov Mars GravityAssist EducatorWorkshop http://dawn.jpl.nasa.gov/DawnKids/activities.asp – – – n_engine_interactive/index.html http://dawn.jpl.nasa.gov/mission/io http://dawn.jpl.nasa.gov/DawnCla http://dawn.jpl.nasa.gov/getInvo http://dawn.jpl.nasa.gov lved/index.asp?page=overview ssrooms/1_hist_dawn%5Cindex.asp /mission/live_shots.asp DawnDawn Back-up Slides DawnDawn Braille-2km AnneFrank-5km Steins-6km Gaspra-18km Eros-36km Ida-56km Mathilde 60km Lutetia 95km Longest dimension Asteroid Flybytargets toscale DawnDawn Two identicalunitstoflyfor These functionsaremission critical Supports: ImagingScience 100% redundancy 1024 xpixels 7 filters + clearchannel + 7 filters iFoV (1pixel) 93 µrad 5.5 F/8 system pixel size 14 µm frame-transfer CCD frame-transfer ° x 5.5 Gravity Science Topography Navigation ° FoV Framing Camera FC currentdesign(left) FC EM(below) 21 DawnDawn present signatures ofrock-forming mineralsare surface in therange0. Ceres and measurements of theVesta VIR will allowtoperformspectroscopic Visible InfraredMapping 35-5.01 um weremost Spectrometer • • modules the sameopticalhead.Itismadeof 2 spectrometer housing two datachannelsin VIR experimentisacompact imaging Electronics box head Optical REQUIREMENT Field of view (mrad) Field of view Spatial Resolution (mrad) relative absolute Accuracy Radiometric Spectral Accuracy Spectral Resolution( ( Spectral Range μ m) λ / Δλ ) 50-170 1.0 0.25 - 64 0.250 < 10% < 20% 0.6 nm VIR VISIBLE 30-170 5.0 0.95 - 64 0.250 < 10% < 20% 3 nm VIR IR 22 DawnDawn Operating modes Features space environment the suppression ofbackground from Design enablesmeasurement and (new technology) Cadmium and ZincTelluride Germanate Gamma rayspectroscopy usingBismuth glass andboron-loadedplasticphoswich Neutron spectroscopyusingLi-loaded Anneal Operating Standby GRaND 18.0 cm Data Rate (bps) Rate Data Anneal Operating Standby (mW) Power Mass (g) Cutaway viewofGRaND 2802,560 1,680 12,800 11,200 900 10,100 ,0 adjustable 3,100 420 1,400 B Uncertainty CBE 25.7 cm DawnDawn Telescope And CeresWith HubbleSpace Recent Observations ofVesta McFadden etal.2007 24 DawnDawn And nowfor a dwarfplanet 25 DawnDawn 220 nm 330 nm 555 nm 220 nm 330 nm 555 nm Ceres Lightcurve- Li etal.2005 Ceres Lightcurve- 3. 2. 1. wavelengths – color variations color wavelengths – Different shapesatthree to albedo variations however shouldbetotallydue Amplitude issmall(0.04mag), observations consistent withearlier all amplitude, andshapeare Lightcurve magnitude, 26 Thomas etal. 2005 DawnDawn Ceres tooisdifferentiated 27 DawnDawn • • • The DawnSpacecraftwilltravel Launch Sept.27,2007 Dawn’s Itinerary: To theasteroids, 4Vesta and 1Ceres. In almosttenyears 6.3 billionkilometers(almost4 miles) Exploring NewWorlds Vesta DawnDawn – – – – – – – – New Roads School,University ofMaryland, andMcREL ASI –ItalianSpace Agency Max PlanckInstitute forSolarSystemResearch AerospaceCenter DLR –German Los AlamosNationalLaboratory Orbital SciencesCorporation PropulsionLaboratory JPL –Jet University ofCalifornia,LosAngeles • • • • • • • • Education andPublicOutreach VIR Framing Camera Framing Camera GRAND instrument Spacecraft designandbuild Management andNavigation Scientific Leadership Partners DawnDawn http://dawn.jpl.nasa.gov Learn More! DawnDawn Meteoritic Samples fromVesta 31 DawnDawn DawnDawn months Target ofDawn, scheduledtoorbit Ceresin2015for5 ammoniated (Kingetal.1992) Probably hydrated( a Biggest asteroidwitha diameterabout1000km First asteroiddiscovered in1801 months Target ofDawn, scheduledtoorbit Ceresin2015for5 ammoniated (Kingetal.1992) Probably hydrated( a Biggest asteroidwitha diameterabout1000km First asteroiddiscovered in1801 =2.77 AU, =2.77 AU, Background ofCeres Background ofCeres e e =0.079, =0.079, Lebofsky Lebofsky i i =10.6 =10.6 ° ° 1981, 1981, Feierberg Feierberg Feierberg 1981) or 1981) or