NeptuneDMASlidesforOPAGPoster

DineshK.Prabhu&GaryA.AllenAMA,Inc.@NASAAmesResearchCenter,Moffe7Field,CA94035

April4,2019

AtmosphericModelforNeptuneDMASimula?ons

•  ModifiedversionofNeptuneGRAMusedintrajectorysimula@ons•  Modifica@onsresultinlowerdensity

•  ActualGRAMprofilecomparesverywellwithdatafromMosesetal.(Icarus,307,pp.124-45,2018)

•  Atmosphericcomposi@onheldconstantatH2:He=0.85:0.15(byvol.)

•  Aerohea@ngoccursinthestratosphere

•  Configura@on(s)withRnose=1m•  12m(dia.)70°sphere-cone(withADEPTskirt)•  6m(dia.)70degsphere-cone(withoutADEPTskirt)

•  3DOFtrajectorydevelopedusingTRAJforentrystate:•  Equatorial,posigradeentry•  mE=4000kg,VE(inert.)=28km/s,γE(inert.)=-10.9°,•  ADEPTskirtje]sonat252s•  m@Je]son=1800kg,Aerocaptureapoapsis≈430000km

•  Stagna@onpointaerothermalenvironmentsfromengineeringcorrela@ons;noradia@vehea@ng

NeptuneDMATrajectoryStag.PointAerothermalEnvironments

Al@tudevs.Velocity

Decelera@onLoad Stag.PointPressure Stag.PointHeatFlux&Load

NeptuneDMATrajectoryDistributedAerothermalEnvironments(atPeakHea?ngPoint)

•  DistributedaerothermalenvironmentsusingDPLR(v4.04)•  7-sp(H2,He,H,H2

+,H+,He+,ande-)gasmodel•  Bothlaminar&turbulentflowsimula@ons•  Wallassumedfullycataly@cwithemissivityof0.85•  Predictedstagna@onpointpressureandheatfluxcompare

verywellwithes@matesfromengineeringcorrela@ons•  DistributedaerothermalenvironmentsusedinsizingTPS

materialforrigidnose,andcarbonfabric(ADEPTskirt)

ANeptuneOrbiterConceptusingDragModulatedAerocaptue(DMA)andtheAdaptable,DeployableEntryandPlacementTechnology(ADEPT)

(Deployed for Entry)

(Stowedin5mFairing)