Conducting human exploration missions beyond low-Earth orbit to destinations such as Mars and asteroids will require substantial work to ensure the well-being of the astronauts. These new operational conditions, which will include long periods in microgravity, will pose health risks that are currently not well understood and perhaps unanticipated. Developing and applying advanced tools to predict, assess, and mitigate potential hazards to astronaut health is critical. NASA’s Digital Astronaut Project (DAP) is working to implement rigorously validated computational models to help predict and assess spaceflight health and performance risks, and enhance countermeasure development.

1. Conductinghumanexplorationmissions
beyondlow-Earthorbittodestinationssuch
asMarsandasteroidswillrequiresubstantial
worktoensurethewell-beingoftheastronauts.
Thesenewoperationalconditions,whichwill
includelongperiodsinmicrogravity,willpose
healthrisksthatarecurrentlynotwellunderstoodhealthrisksthatarecurrentlynotwellunderstood
andperhapsunanticipated.
Developingandapplyingadvancedtoolsto
predict,assess,andmitigatepotentialhazards
toastronauthealthiscritical.NASA’sDigital
AstronautProject(DAP)isworkingtoimplement
rigorouslyvalidatedcomputationalmodelsto
helppredictandassessspaceflighthealthandhelppredictandassessspaceflighthealthand
performancerisks,andenhance
countermeasuredevelopment.

2. IncollaboratingwithNASA’sExerciseandPerformancePortfolio,andtheAdvanceExercise
ConceptsProject,theDAPisdevelopingbiomechanicalmodelsofexercisesperformedwiththe
AdvancedResistiveExerciseDevice(ARED)thatisusedaboardtheInternationalSpaceStation
andcompactexercisedevicesthatareintendedforfutureexplorationclassmissions.These
computationalmodelsareusedbyNASAresearchersandthosedevelopingexercisehardware
requirementstoensurethatdevicesusedduringexplorationmissionsprovidethetypesand
amountofphysicalexerciseastronautswillneedtomaintainhealthybonesandmuscle.amountofphysicalexerciseastronautswillneedtomaintainhealthybonesandmuscle.
SimulationsofExerciseCountermeasuresinMicrogravity

3. Inordertohelpphysiologistsgainfurtherinsightintotheprocessesofmusclelossinspace,
theDAPisdevelopingahighfidelitymusclemodulethatwillbeintegratedwiththeexercise
biomechanicalmodels.Onceintegratedwiththeexercisemodels,themusclemodulewill
simulatetheresponseofmusclephysiologytoexercisecountermeasuresduringspaceflight
missions.Itwillalsobepossibletosimulatemissiontasksanddeterminetheastronauts’ability
toperformthetaskafteralengthoftimeinspace.
SimulatingSpaceflightInducedMuscleChanges

4. Source:NASA
Source:NASA
IncollaborationwiththeNASABoneDisciplineleadscientistandbonestrengthsimulations
developedbytheUniversityofCaliforniaatIrvine,theDAPisdevelopingthefirstsimulations
ofboneadaptationtomicrogravityconditions.Thisworkfocusesonbone-strengthchanges
duetodemineralizationandarchitecturalchanges,andhowexercisecountermeasurescan
beappliedtomitigateadverseeffectsofspaceflightonbone.Basedontheoutcomesofthese
simulations,itmaybepossibleforclinicianstoguidetheactivitiesofastronautsinorderto
minimizeriskoffractureduringplanetaryexplorationandaftertheyreturnfromamission.minimizeriskoffractureduringplanetaryexplorationandaftertheyreturnfromamission.
ComputationalBonePhysiology

5. Asignificantnumberofastronautswhohaveparticipatedin
long-durationspaceflightmissions(~6months)aboardthe
InternationalSpaceStationhavereturnedwithpermanent
changesintheirvisualacuity.Spacemedicineexpertshave
suggestedthatthelargedisplacementofbodyfluidtoward
theheadcausedbymicrogravityexposuremaybepartly
responsibleforthesechangesviabiomechanicalpathways.responsibleforthesechangesviabiomechanicalpathways.
TheDAPisbuildingonestablishedresearchinlumped-
parameter,finite-element,andcomputationalfluiddynamic
numericalmodelingtocharacterizetheappropriate
biomechanicalresponseofthecardiovascular,central
nervousandvisualsystemsinmicrogravity.These
computationalsimulationswillbeimplementedtoinform
researchbytestinghypotheticalbiomechanicalpathwaysbyresearchbytestinghypotheticalbiomechanicalpathwaysby
whichgravitationalunloadingcouldcausechangestothe
structureoftheeye.Identifyingcriticalparametersand
featuresalongthecausalchainofbiomechanicalresponse
canthenbeusedtoguidecountermeasuredevelopment.
ModelingandSimulationofMicrogravityInduced
VisualImpairmentandIntracranialPressure
Source:GoogleBody

6. ThegoaloftheDigitalAstronautProject(DAP)istoimplementwell-validatedcomputational
modelstohelppredictandassessspaceflighthealthandperformancerisks,andenhance
countermeasuredevelopment.TheDAPaimstoaccomplishthesegoalsthrough
multidisciplinaryandcollaborativeapproachby:
1.Partneringwithsubject-matterexpertstoaddresshumanhealth-riskknowledgegapsand
countermeasuredevelopmentdecisions
2.Modeling,simulating,andanalyzingphysiologicalresponsestoexposuretoreduced2.Modeling,simulating,andanalyzingphysiologicalresponsestoexposuretoreduced
gravityandspaceflight-analogenvironments
3.Providingtimelyinformationtocontributetomissionarchitectureandoperationsdecisions
inareaswhereclinicaldataarelacking
LealemMulugetaofUSRA’sDivisionofSpaceLifeSciences(DSLS)istheDAPProjectScientist,
akeymemberoftheprojectleadershipresponsibleforallscientificcontentanddirectionoftheproject.
TheDigitalAstronautProject