Pre-Decadal Study Summary CAPS Meeting, 29 March 2017 Amy ... · < 12 years using Atlas V •...

IceGiantsPre-DecadalStudySummary

CAPSMeeting,29March2017

AmySimon(NASAGoddardSpaceFlightCenter)MarkHofstadter(JetPropulsionLaboratory,CaliforniaInstituteof

Technology)andtheIceGiantStudyTeam

1Predecisional - Forplanninganddiscussionpurposesonly.URSCL#265147 ©2017AllrightsReserved

Predecisional - Forplanninganddiscussionpurposesonly.URSCL#265147

StudyGoalandObjectivesGoal• Assessscienceprioritiesandaffordablemissionconcepts&optionsforexplorationoftheIceGiantplanets,UranusandNeptuneinpreparationforthenextDecadalSurvey.

Objectives• Evaluatealternativearchitecturestodeterminethemostcompellingsciencemission(s)thatcanbefeasiblyperformedwithin$2B($FY15)• Identifypotentialconceptsacrossaspectrumofpricepoints

• Identifymissionconceptsthatcanaddressscienceprioritiesbasedonwhathasbeenlearnedsincethe2013–2022DecadalSurvey

• Identifyenabling/enhancingtechnologies

• AssesscapabilitiesaffordedbySLS

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KeyStudyGuidelines(ExcerptedfromStudyGuidelinesDocument)• EstablishaScienceDefinitionTeam• AddressbothUranusandNeptunesystems• Determinepros/consofusingonespacecraftdesignforbothmissions(possibilityofjointdevelopmentoftwocopies)

• Identifymissionsacrossarangeofpricepoints,withacostnottoexceed$2B($FY15)permission

• Performindependentcostestimateandreconciliationwithstudyteam• Identifymodelpayloadforaccommodationassessmentforeachcandidatemission.

• ConstrainmissionstofitonacommercialLV• Alsoidentifybenefits/costsavingsifSLSwereavailable(e.g.,time,traj.,etc.)

• Launchdatesfrom2024to2037(focusonthenextdecadalperiod)• Evaluateuseofrealisticemergingenablingtechnologies;distinguishmissionspecificvs.broadapplicability

• Identifycleaninterfacerolesforpotentialinternationalpartnerships

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WhyUranusandNeptune?• Theserelativelyunexploredsystemsarefundamentallydifferentfromthegasgiants(JupiterandSaturn)andtheterrestrialplanets- UranusandNeptuneare~65%waterbymass(plussomemethane,ammoniaandotherso-called“ices”).Terrestrialplanetsare100%rock;JupiterandSaturnare~85%H2andHe

• Icegiantsappeartobeverycommoninourgalaxy;mostplanetsknowntodayareicegiants• Theychallengeourunderstandingofplanetaryformation,evolution,andphysics- Modelssuggesticegiantshaveanarrowtimewindowforformation.Ifcorrect,whyaretheysocommoninotherplanetarysystems?

- WhyisUranusnotreleasingsignificantamountsofinternalheat?Doesitsoutputvaryseasonally?

- Whyaretheicegiantmagneticfieldssocomplex?Howdotheunusualgeometriesaffectinteractionswiththesolarwind?

!

Uranusin2012(Sromovskyetal.2015)and1986(right,Voyager)

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12KeyScienceObjectives

PlanetaryInterior/Atmosphere• Planetarydynamo• Atmosphericheatbalance

• Tropospheric3-Dflow

Rings/Satellites• Internalstructureofsatellites• Inventoryofsmallmoons,includingthoseinrings

• Ringandsatellitesurfacecomposition

• Ringstructuresandtemporalvariability

• Shapeandsurfacegeologyofsatellites

• Triton’satmosphere:origin,evolution,anddynamics

Magnetosphere• Solarwind-magnetosphere-ionosphereinteractionsandplasmatransport

HighestPriority• Interiorstructureoftheplanet• Bulkcompositionoftheplanet(includingisotopesandnoblegases)

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UranusorNeptune?• UranusandNeptunesystemsareequallyimportant

• AFlagshipmissiontoeitherisscientificallycompelling

• Itisimportanttorecognize,however,thatUranusandNeptunearenotequivalent.Eachhasthingstoteachustheothercannot.Forexample- Nativeice-giantsatellites(Uranus)vs.capturedKuiper

Beltobject(Neptune)- Thesmallest(Uranus)andlargest(Neptune)releasesof

internalheat,relativetoinputsolar,ofanygiantplanet- Dynamicsofthin,denseringsanddenselypacked

satellites(Uranus)vs.clumpyrings(Neptune)

Uranus(top,Sromovskyetal.2007)andNeptune(bottom,Voyager)

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ModelPayloadsChosentomaximizesciencereturn. SimilarforUranusandNeptune.

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Modelpayloadforprobe:• Massspectrometer• ASI(density,pressureandtemperatureprofile)• Hydrogenortho-parainstrument• Nephelometer

Modelpayloadfororbiterorflybys/c

50kgorbiterpayloadaddressesminimumacceptablescience• NAC,• DopplerImager,• Magnetometer.

90kgorbiterpayloadpartiallyaddresseseachscienceobjective.Addto50kgcase:• Vis/NIR imagingspect.,• RadioandPlasmasuite,• ThermalIR,• Mid-IRorUVspect.

150kgorbiterpayloadcomprehensivelyaddressesallscienceobjectives.Addto90kgcase:• WAC,• USO,• EnergeticNeutralAtoms,• Dustdetector,• Langmuirprobe,• Radiosounder/Massspec.


MissionArchitectures• Widerangeofarchitecturesassessed;rankedscientificallyandcosted

• Anorbiterwithprobemeetsthesciencerequirementsandstudycosttarget

• Addingasecondspacecrafttotheothericegiantsignificantlyenhancesthesciencereturnataproportionallyhighercost

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!


GettingtotheIceGiants• Launchintervalstudied:[2024– 2037]

• Totalmissionduration<15yearsincludingatleast2yearsofscience

• Interplanetaryflighttime:• 6– 12yearstoUranus• 8– 13yearstoNeptune

LaunchVehicles

•AtlasV•Delta-IVHeavy•SLS-1B

InterplanetaryTrajectory

•Chemical+DSM+GA•SEP+GA•REP+GA•DualSpacecraft

GravityAssist(upto4perTraj.)

•Venus•Earth•Mars•Jupiter•Saturn

TargetBodies

•Uranus•Neptune

SEPPower

•15kW•25kW•35kW

EPEngines

•NEXT1+1(SEP)•NEXT2+1(SEP)•NEXT3+1(SEP)•XIPS(REP)

OrbitInsertion

•Chemical(Bi-Prop)•Chemical(cryo)•REP•Aerocapture

• Tensofthousandsoftrajectoryoptionstobothplanetswereexamined• Orbitinsertion∆VatbothUranusandNeptuneishigh

Neptune:2.3-3.5km/sUranus:1.5-2.5km/s

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MissionDesignTakeaways• Launchesarepossibleanyyearstudied(2024-2037)

• Optimallaunchopportunitiesarein2029-2032,usingJupitergravityassist• MissionstoUranusviaSaturnarepossiblethroughmid-2028• NoNeptuneviaSaturntrajectoriesinthestudytime-range

• Chemicaltrajectoriesdeliveraflagship-classorbiter(>1500kgdrymass)toUranusin<12yearsusingAtlasV• Delta-IVHeavycanreduceinterplanetary

flighttimeby1.5years

• Nochemicaltrajectoriesexistfordeliveringaflagship-classorbitertoNeptunein<13yearsusingAtlasVorDelta-IVHeavylaunchvehicles.SLSorLongerflighttimeswouldbeneeded.

• SEPEnablesaflagshiporbitertoNeptunein12-13years• Implementedasseparablestagetominimizepropellantrequiredforinsertion

EVEEJU

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BenefitsofSLSAllsingleplanetmissionsstudiedareachievablewithexistingELVs

SLScanprovideenhancingbenefits:• Increasesdeliverablemassandlowersflighttimeby3to4years

• EnableschemicalNeptunemissionin11.5yr.• Enablestwospacecraftmissionswithasinglelaunch

• Increaseslaunchopportunities

Whencombinedwithaerocapturecapability,enablesverylowflighttimesforbothUranus(<5yr.)andNeptune(<7yr.)

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MissionConceptPointDesigns

FourbasicmissionconceptsweretakenthroughTeamXforpointdesignandcosting.Theseconceptswerechosentoconstrainthescience/costparameterspace:

• Uranusorbiterwith~50kgpayloadandatmosphericprobe• Uranusorbiterwith~150kgpayloadwithoutaprobe• Neptuneorbiterwith~50kgpayloadandatmosphericprobe• Uranusflybyspacecraftwith~50kgpayloadandatmosphericprobe

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Keyarchitecturesfullyassessedusingcommonbuildingblocks

NeptuneOrbiterwithProbe,SEP,and50kgpayload

UranusFlybywithProbeand50kgpayload

UranusOrbiterwithProbeand50kgpayload

UranusOrbiterwith150kgpayload

Launchmass:7364kg

Launchmass:1525kg Launchmass:

4345kg Launchmass:4718kg

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ConceptSummary

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CaseDescription

NeptuneOrbiterwithprobeand<50kgsciencepayload.IncludesSEPstage forinnersolarsystemthrusting.

UranusFlybyspacecraftwithprobeand<50kgscience

payload

UranusOrbiterwithprobeand<50kgsciencepayload.

Chemicalonlymission.

Uranus Orbiterwithoutaprobe,butwith150kg

sciencepayload.Chemicalonlymission.

ScienceHighestpriorityplus

additionalsystemscience(rings,sats,magnetospheres)

Highestpriorityscience(interiorstructureand

composition)

Highestpriorityplusadditionalsystemscience

(rings,sats,magnetospheres)Allremotesensingobjectives

TeamXCostEstimate*($k,FY15) 1971 1493 1700 1985

AerospaceICE($k,FY15) 2280 1643 1993 2321

Payload 3instruments†+atmosphericprobe

3instruments†+atmosphericprobe

3instruments†+atmosphericprobe 15instruments‡

PayloadMassMEV(kg) 45 45 45 170LaunchMass(kg) 7365 1524 4345 4717

LaunchYear 2030 2030 2031 2031FlightTime(yr) 13 10 12 12

TimeinOrbit(yr) 2 Flyby 3 3TotalMissionLength(yr) 15 10 15 15

RPS use/EOMPower 4eMMRTGs/376W 4eMMRTGs/425W 4eMMRTGs/376W 5eMMRTGs/470WLV DeltaIVH+25kWSEP AtlasV541 AtlasV551 AtlasV551

PropSystem DualMode/NEXTEP Monopropellant DualMode DualMode

*IncludescostofeMMRTGs,NEPA/LA,andstandardminimaloperations,LVcostnotincluded†includesNarrowAngleCamera,DopplerImager,Magnetometer‡includesNarrowAngleCamera,DopplerImager,Magnetometer,Vis-NIRMapping Spec.,Mid-IRSpec.,UVImagingSpec.,PlasmaSuite,ThermalIR,EnergeticNeutralAtoms,DustDetector,LangmuirProbe,MicrowaveSounder,WideAngleCamera


CostSummary,KeyArchitectures

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Description

NeptuneOrbiterwithprobeand50kgsciencepayload(requiresSEPstage)

UranusFlybyspacecraftwithprobeand50kgsciencepayload

UranusOrbiterwithprobeand50kgsciencepayload

Uranus Orbiterwithoutaprobe,and150kgscience

payload

TeamXCostEstimates($k,FY15)TotalMissionCost* 1971 1493 1700 1985

AerospaceICE($k,FY15)TotalMissionCost* 2280 1643 1993 2321

*IncludescostofeMMRTGs,NEPA/LA,andstandardoperations. LVcostnotincluded.

• Neptunemissionscost~$300MmorethanUranusforcomparablesciencereturn(drivenbySEP)

• TheUranusorbiterwithprobemissionisestimatedtobeintherangeof$1.7to$2.6Bdependingontheorbiterpayload(50-150kgrange)andreserveposture

The cost information contained in this document is of a budgetary and planning nature and is intended for informational purposes only. It does not constitute a commitment on the part of JPL and/or Caltech


NewTechnologiesConsideredMissionenhancing,butnotrequired• InSpaceTransportation

• Aerocapture• LOX-LH2chemicalpropulsion• RadioisotopeElectricPropulsion(REP)

• OpticalCommunicationsBeyond3AU

• Smallsatellites

• AdvancedRadioisotopePower• SegmentedModularRadioisotopeThermoelectricGenerator(SMRTG)• HighPowerStirling RadioisotopeGenerator(HPSRG)

Enabling• eMMRTG radioisotopepowersystem• HEEET thermalprotectionsystem• Giantplanetseismometer(e.g.DopplerImager)

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• IceGiantsconceptscanbeimplementedwitheMMRTG andHEEETtechnologycurrentlyindevelopment.GPseismologyisanopportunityforground-breakingscience.


StudyRecommendations• AnorbiterwithprobebeflowntoUranus,launchingnear2030• AUranusorNeptuneorbitershouldcarryapayloadbetween90and150kg

• Two-planet,two-spacecraftmissionoptionsshouldbeexplored• ThedevelopmentofeMMRTGs andHEEET isenablingandshouldbecompletedasplanned

• Thereshouldbecontinuedinvestmentsinground-basedresearch(theoreticalandobservational)andinstrumentation.Importantareasincludeupper-atmosphericproperties,ring-particleimpacthazard,andgiant-planetseismology

• Internationalcollaborationsshouldbeleveragedtomaximizethesciencereturnwhileminimizingthecosttoeachpartner

• Anadditionalmissionstudyshouldbeperformedthatusesrefinedprogrammaticground-rulestobettertargetthemissionlikelytofly

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AnIceGiantMissionin2030

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Whyshouldwebeexcitedaboutthispossibility?• Thismissionengagesalldisciplinesintheplanetarysciencecommunity,aswellasheliophysics andexoplanetscientists

• LaterlauncheslosetheopportunitytomaptheNorthernHemispheresoftheUraniansatellites,andsampleuniquesolarwindgeometries

• Themissionrequiresnonewtechnology,andislow-risk

• CompletestheDecadalSurvey'srecommendedFlagshipmissions

• Partners,especiallyESA,areinterestedincost-sharing

Ó Woods Whole Oceanographic Institute & Kevin Hand

Backup

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InternationalPartnerships• Abroadoptionspaceexistsforinternationalpartnerships- Scientists- Instruments- Probes- Spacecraftorspacecraftsubsystems- Groundstations- Possiblesecondspacecraftoneitherasharedorseparatelaunchvehicle

• ESAreceivedabriefingon31January- TheywillproposeamechanismfortheirparticipationinanIceGiantFlagship

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ScienceObjectivesSummary• AllelementsoftheIceGiantsystems(interior,atmosphere,rings,satellites,magnetosphere)haveimportantscienceobjectivesthatcannotbemetthroughEarth-basedobservations

• Determiningtheinteriorstructureandbulkcompositionoftheicegiantsisidentifiedasthehighest-payoffscience

• Scientificandtechnologicaladvances,andimprovedtrajectories,makethesemeasurementshigherprioritythanintheDecadalSurvey

• 12keyscienceobjectivesdrivemissionarchitectures(nextslide)

• Allscienceobjectivesareconsistentwithandtraceabletothedecadalsurvey

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SEPTradespaceExample

• UsefulInsertedMass=MassafterOrbitinsertion– PropellantTanks• Thecoloredlegenddepictsinterplanetaryflighttimeinyears.Notethatthecolorsareuniquetoeachplot.• Tradespacehighlightshighperformingtrajectories,backuplaunchopportunitiesandallowsustopicka

baselinemissiontrajectoryforfurtherrefinementsFiguresshownareforDelta-IVheavylaunchvehiclewith25kWSEPstageonly

25 26 27 28 29 30 31 32 33 34 35 36 370

1,000

2,000

3,000

4,000

5,000

Launch Date (year)

UsefulInserted

Mass(kg)

Uranus, Delta-IV Heavy, 25 kW, NEXT 2+1

6.07.08.09.010.011.012.0

25 26 27 28 29 30 31 32 33 34 35 36 370

1,000

2,000

3,000

4,000

5,000

Launch Date (year)

UsefulInserted

Mass(kg)

Neptune, Delta-IV Heavy, 25 kW, NEXT 2+1

9.010.011.012.013.0

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CostingApproach• CostestimatesdevelopedbyJPL’sTeamXandtheAerospaceCorporation

• AssumptionsusedforcostingcomefromStudyGroundRules:• Allcostsin$FY15;Includeminimum30%reserves(A–D),15%(E-F)• AssumeClassB(perNPR8705.4),CategoryI(perNPR7120.5)mission• ExcludeLV• IncludecostofRPS includingNEPA/LA• Includeoperations(fulllifecyclemissioncost)• IncludeDSNasseparatelineitem• ReservesexcludedonRPSandLV

• Aerospaceindependentcostestimate(ICE)generallyhigherthanTeamXasaresultofmodelingdifferencesforflightsystemandoperations• Differenceswithintheerrorbarsoftheestimationtechniques

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ScienceDefinitionTeam

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Chairs: MarkHofstadter(JPL),AmySimon(Goddard)

ESAMembers:AdamMasters(Imp.College)DiegoTurrini (INAF-IAPS/UDA)

SushilAtreya(Univ.Mich.)DonaldBanfield (Cornell)JonathanFortney(UCSC)AlexanderHayes(Cornell)MatthewHedman (Univ.Idaho)GeorgeHospodarsky (U.Iowa)

KathleenMandt (SwRI)MarkShowalter(SETI Inst.)KristaSoderlund (Univ.Texas)ElizabethTurtle(APL)


MissionDesignTeam

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• NASAInterface: CurtNiebur ESAInterface: LuigiColangeli

• StudyLead: JohnElliott JPLStudyManager: KimReh

MissionConceptDesignTerriAnderson(costing)DavidAtkinson(probes)Nitin Arora (trajectory)ChesterBorden(systemeng.)JimCutts (technology)YoungLee(RPS)Anastassios Petropoulos(trajectory)TomSpilker(science,systemeng.)DavidWoerner (RPS)

ScienceDefinitionTeamCo-Chairs:M.Hofstadter/A.SimonMembers:Seenextslide

OtherOrganizationsLangleyResearchCenter(TPS)AmesResearchCenter(TPS)PurdueUniversity(missiondesign)AerospaceCorp.(ICE)

Pre-Decadal Study Summary CAPS Meeting, 29 March 2017 Amy ... · < 12 years using Atlas V •...

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