Fusion-EnabledPlutoOrbiterandLander

MichaelPaluszekPrincetonSatelliteSystems,Inc.

US-JapanCT2016August22-24

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OutlineofTalk

● Electricpropulsion● Plutomissionoverview● Missiondesign● Spacecraftdesign● DFDoverviewandstatus

⁃ FRCwithodd-parityRFheating

⁃ D–3Hefuel● DFDsubsystems● Workinprogressandconclusions

SupportedbyNASAInnovativeAdvancedConceptsProgramunderawardNNX16AK28G

SimulationofDFDPlutoApproach

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ElectricPropulsion

● Criticalrelations⁃ Power/thrustrelationship⁃ Rocketequationwithspecificpower

● Specificpoweristhekeytoperformance⁃ Ratioofpowerinthethrusttoengine

mass● Exhaustvelocitydeterminesachievablevelocitychange

Exhaustvelocityofengine

Totalvelocitychange

Massoffuel

MassofpayloadandengineFractionofmassproportionaltofuel

Thrust

DFDgetstoPlutoin4yearsThisisjustthePlutoorbitinsertionmaneuver

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SpecificPower

● Plotonrightbasedonworkdoneassumingdirectinsertion

● Otherelectricpropulsionsystems⁃ Solar–notapplicabletoouterplanetmissions

⁃ FissionElectric

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Destination:PlutoOrbit

PutaspacecraftinorbitaroundPluto,poweralanderusingopticaltransmission,returnhigh-definitionvideo–

andgetthereinonly4years!

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PlutoMission

● Deliverpayload1000kgoforbiterandlander

● 1158Lof3Hefortheentiremission● Arrivesinjust4years● Provides2MWofelectricalpower

⁃ Beam30kWdowntolander● Launchmasscanbeaccommodatedbyalmostanylaunchvehicle

● 3Hefuelcanbepurchasedinsufficientquantitiesnowfromavailablesuppliers

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PlutoMissionComparison

Parameter NewHorizons DFDMission

TraveltimetoPluto 9.5years 4years

Delta-V 290m/s 70,000m/s

PoweratPluto 200W 2,000,000W

DataratetoEarth 1kbit/s >1,000,000kbit/s

Fuel Plutonium D-3He

Trajectory JupiterSwingby Direct

Missiontype Flyby Orbit

Lander No Yes

BottomLine:Youcan’tdotheproposedmissiontoPlutowithanyothertechnology.

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MissionOutline

● Earthdeparture ● Acceleration–Coast–Deceleration

⁃ Dependsonavailablethrust● InsertionintoPlutoflybyorbit● Orbitinsertion● Orbitoperations

⁃ Landerdeployment⁃ Plutoobservations⁃ Landerpowerfromorbit

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Spacecraft

● WiderangeofscientificinstrumentsforPlutoorbitsurveyandalander

● Largeradiatorsforwasteheatrejection

● CylindricalstructureissunshadewithMLI

● OpticalcommunicationsforHDTVbandwidthtoEarth

● Fullyautonomousguidance,navigationandcontrol

ComparisonwithHubbleSpaceTelescope

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SpacecraftSubsystems

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Guidance,NavigationandControl(GN&C)

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GN&C

● Opticalnavigationusedthroughout⁃ ReducesrelianceonDeepSpaceNetwork

⁃ Providescontinuousupdatesduringburns

⁃ OperatesinheliocentricorPlutocentricmodes

● Reactionwheelsforattitudecontrol

● Steeredplasmaplumesforpitchandyawmomentumunloadingandcontrolduringburns

● Attitudecontrolthrustersforrollcontrolandunloading

UKFisUnscentedKalmanFilter

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DeparturefromEarth

● Twooptions⁃ Directinsertionintoheliocentrictrajectory

⁃ DeparturefromLEO● Directinsertion(rocketputsthevehicledirectlyintoheliocentricorbit)requiresaDeltaIVHeavyclasslauncher⁃ $350Mlaunchcost

● Departurefromlowearthparkingorbit⁃ $60Mlaunchcost⁃ Requiresadditionalfuel⁃ Allowsforon-orbitcheckout

SimulationofDFDPlutoVehiclenearISSpriortodeparture

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DepartureTrajectory

● AssumeISSorbit⁃ Allowsastronautcheckoutpriortodeparture

● Burnalongvelocityvector⁃ Notoptimal

● 40Nthrustassumed● Orbitbecomeshyperbolicin7.5days⁃ eisorbiteccentricity⁃ >1ishyperbolic

● Majorcostsavings● On-orbitcheckoutreducesmissionrisk

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ArrivalatPluto

● Optimaltrajectory⁃ UsesMATLAB’sfmincon

▪ Bruteforcedirectmethod▪ Thereareothermethods

⁃ Twodimensionalproblem⁃ Inequalityconstraintonaccelerationmagnitude

⁃ Startsinflybyhyperbola⁃ Usestwicethevelocitychangeofanimpulsiveburnatclosestapproach

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PrincetonFieldReversedConfiguration(PFRC)

8/19/16

● RFheatingwithrotatingmagneticfieldsnaturallylimitsreactorsize⁃ Plasmaradiusinrange20-40cm⁃ Powerof1-10MWisidealforspace

● Confinementwithsuperconductingcoils

● Ultralowradiation

• Linearconfigurationallowsforconfigurationasarocketengine

● FlowmoreD+toaugmentthrust● Exitviamagneticnozzle● Variableexhaustvelocity

● 50to20,000km/s● P=0.5Tue/η,thrust~10-50N

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StatusofPFRCDevelopment

8/19/16

● PrincetonPlasmaPhysicsLaboratoryperformingexperimentswithDept.ofEnergyfunding⁃ ConcludedPFRC-1a,b,cin2011⁃ PFRC-2operatingnow;goaltodemonstratekeVplasmas

withpulselengthsto0.3s⁃ Computationalstudiesonplasmadetachmentinnozzle

● PrincetonSatelliteSystemsperformingmissionandtrajectorydesign,spacebalanceofplantstudiesunderIR&DandnowNIAC⁃ FourjointPPPL/PSSpatents

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DFDDiagram

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DFDSubsystems

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HeatRecycling

● Braytoncycleheatengine⁃ Heathighpressuregastodowork

● UsedinHighTemperatureGasCooledFissionReactors

● Heliumworkingfluid● Pairedcompressor/turbinesets

withcounter-rotatingturbinesandcompressors

● Commonshaftforcompressor,turbineandgenerator

● Needformultiplecompressorandturbinestagesandrecuperatortobedetermined

● Largeradiatorwings

HTGCR

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SuperconductingCoilsDesignedforSpace

● AlphaMagneticSpectrometer-02● Lookingforanti-matteranddarkmatter

● Cooledwithsuperfluidhelium

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SuperconductingCoils

● Eightdiscretecoilsina4mmachine⁃ Someripplewhichwouldbereducedbytheplasmafield

● AxialfieldcompatiblewithHTSandNbTiLTS● Forcesbetweencoilsare5.7×106N

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PowerGenerationandDistribution

● Powergeneratedbya3phaseaxial-fluxHalbachGenerator⁃ Distributionis3phasetoRFdrive⁃ 98%efficientatdesignpoint⁃ AC/DCconvertersand3phasetoonephaseconvertersasneeded

● AverysmallHalbachmotor/generatordevelopedatPrincetonSatelliteSystemsforanArmysatellite

Driverconfiguredasmotor

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Radio-FrequencyHeating

● Odd-parityrotatingmagneticfield● ClassEpowerRFamplifiers

⁃ Transistoroperatesasonon/offswitch⁃ Loadnetworkshapeswaveformsothatthecurrentandvoltagedonotsimultaneouslypeakthusminimizedpowerdissipation(P=IV)

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ThrustVectoring

● 1to2degreedeflectionneededtopointthrustvectorthroughthecenterofmass

● Options⁃ Fixedsteeringcoilsafterthemagneticnozzle

⁃ Gimbaledengine⁃ Movingmass

Fieldlinesasdeflectedbyasteeringcoil

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InstrumentationandControl

● Triplyredundant● Radiationhardprocessors

⁃ BAE5545Multi-Core⁃ Fordeepspaceenvironment

● Plasmameasurements● Powersystemmeasurements● Interactswiththespacecraftcontrolsystem

● UsesPPPLCentralInstrumentationandControlSystem(CPCS)datahandlingsystem⁃ BasedonEPICS,Experimental

PhysicsIndustrialControlSystem⁃ SpaceWireusedfornetworking

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Structure

● Handleslaunchloadsandsuperconductingcoilloads⁃ Engineandspacecraftmustundergoshockandvibrationtesting⁃ Fuelsloshisaconsideration

● DeltaIV⁃ Launchloadsaretypically5-6gaxial⁃ Sinusoidalvibration

▪ Thrust:1.27cm5to6.2Hz,1g6.2to100Hz▪ Lateral:0.7g5to100Hz

⁃ Acoustic⁃ Shockatseparation

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ThrustAugmentation

• H or D is used as apropellant- it flows along the magnetic field lines outside of the separatrix;scrape-offlayer(SOL)e-areheatedbythefusionproductsthatareejectedintotheSOL; e-energytransferredtoionsinplumeexpansion

• This reduces the exhaust velocity of the fusion products from 25,000 km/s to ~50 km/s andincreasesthrustto>20N

• Thrust/Ispisadjustablebasedonratethatgasisinjectedintothegasbox• The exhaust plume is directedby amagnetic nozzle, consistingof a throat coil andnozzle coils toacceleratetheflow.

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Startup

● Fusionengineneedstobestartedandrestartedinspace⁃ Initiatenuclearfusion⁃ Chargethesuperconductingcoils⁃ Roughly100secondsofpowerrequired

● EmployscombustorburningD2andO2carriedonboard⁃ D2Ocanberecycledviaelectrolysis

▪ Wehavepowertospare

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FuelStorage

● Storecryogenicdeuteriumandhelium-3● Super-insulatedtanksandpropellantlines

⁃ UsesMulti-layerInsulation(MLI)● Cryocoolerstorecyclevaporthatisnotneededforpropulsion⁃ Samecryocoolersusedforcoilcooling

NASAZeroBoil-offExperiment

Spacecraftwithoutsunshield

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VacuumVessel

● Presentsfirstwalltoplasma⁃ Mustminimizecontamination

● Supportsinstrumentation● Keepsspacecraftdebrisandoutgassingoutsidethefusionchamber

● Pressuredifferentialverysmall

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Shielding

● Protectfromneutronsandradiation⁃ Superconductingcoilsaresusceptibletoneutrondamage

● BremsstrahlungandsynchrotronradiationmustberecycledfortheRMFdrive⁃ Absorbedbytungstenliningthereactorcoolingtubes

● BoronCarbideforneutronshielding● Someshieldingmayberequiredforthepayloadandforoperationinlow-earthorbitnearastronauts

● Wanttominimizeshielding⁃ Reducesspecificpower⁃ Increasesradiusofsuperconductingcoils

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OtherMissions

Marshumanorbitalmission

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Conclusions/WorkinProgress

● Specificpoweriscritical⁃ Thrustpowertomass⁃ Totalelectricplusthrustpowertomass

● Thrust/massdeterminestriptime● Massofallsubsystemsneedstobequantified● Writingadesigndocument

⁃ Preliminarydesignlevelofinformation⁃ Willallowdesigntocriticaldesignlevelinnextphase