Conducting human exploration missionsbeyond low-Earth orbit to destinations suchas Mars and asteroids will require substantialwork to ensure the well-being of the astronauts.These new operational conditions, which willinclude long periods in microgravity, will pose health risks that are currently not well understoodhealth risks that are currently not well understoodand perhaps unanticipated.

Developing and applying advanced tools topredict, assess, and mitigate potential hazardsto astronaut health is critical. NASA’s DigitalAstronaut Project (DAP) is working to implementrigorously validated computational models tohelp predict and assess spaceflight health andhelp predict and assess spaceflight health andperformance risks, and enhancecountermeasure development.

In collaborating with NASA’s Exercise and Performance Portfolio, and the Advance ExerciseConcepts Project, the DAP is developing biomechanical models of exercises performed with theAdvanced Resistive Exercise Device (ARED) that is used aboard the International Space Stationand compact exercise devices that are intended for future exploration class missions. Thesecomputational models are used by NASA researchers and those developing exercise hardwarerequirements to ensure that devices used during exploration missions provide the types andamount of physical exercise astronauts will need to maintain healthy bones and muscle.amount of physical exercise astronauts will need to maintain healthy bones and muscle.

Simulations of Exercise Countermeasures in Microgravity

In order to help physiologists gain further insight into the processes of muscle loss in space,the DAP is developing a high fidelity muscle module that will be integrated with the exercisebiomechanical models. Once integrated with the exercise models, the muscle module willsimulate the response of muscle physiology to exercise countermeasures during spaceflightmissions. It will also be possible to simulate mission tasks and determine the astronauts’ abilityto perform the task after a length of time in space.

Simulating Spaceflight Induced Muscle Changes

Source: NASA

Source: NASA

In collaboration with the NASA Bone Discipline lead scientist and bone strength simulationsdeveloped by the University of California at Irvine, the DAP is developing the first simulationsof bone adaptation to microgravity conditions. This work focuses on bone-strength changesdue to demineralization and architectural changes, and how exercise countermeasures canbe applied to mitigate adverse effects of spaceflight on bone. Based on the outcomes of thesesimulations, it may be possible for clinicians to guide the activities of astronauts in order tominimize risk of fracture during planetary exploration and after they return from a mission.minimize risk of fracture during planetary exploration and after they return from a mission.

Computational Bone Physiology

A significant number of astronauts who have participated inlong-duration spaceflight missions (~6 months) aboard theInternational Space Station have returned with permanentchanges in their visual acuity. Space medicine experts havesuggested that the large displacement of body fluid towardthe head caused by microgravity exposure may be partly responsible for these changes via biomechanical pathways.responsible for these changes via biomechanical pathways.

The DAP is building on established research in lumped-parameter, finite-element, and computational fluid dynamicnumerical modeling to characterize the appropriatebiomechanical response of the cardiovascular, centralnervous and visual systems in microgravity. Thesecomputational simulations will be implemented to informresearch by testing hypothetical biomechanical pathways byresearch by testing hypothetical biomechanical pathways bywhich gravitational unloading could cause changes to thestructure of the eye. Identifying critical parameters andfeatures along the causal chain of biomechanical responsecan then be used to guide countermeasure development.

Modeling and Simulation of Microgravity Induced Visual Impairment and Intracranial Pressure

Source: GoogleBody

The goal of the Digital Astronaut Project (DAP) is to implement well-validated computationalmodels to help predict and assess spaceflight health and performance risks, and enhancecountermeasure development. The DAP aims to accomplish these goals throughmultidisciplinary and collaborative approach by:

1. Partnering with subject-matter experts to address human health-risk knowledge gaps and countermeasure development decisions

2. Modeling, simulating, and analyzing physiological responses to exposure to reduced2. Modeling, simulating, and analyzing physiological responses to exposure to reduced gravity and spaceflight-analog environments

3. Providing timely information to contribute to mission architecture and operations decisions in areas where clinical data are lacking

Lealem Mulugeta of USRA’s Division of Space Life Sciences (DSLS) is the DAP Project Scientist, a key member of the project leadership responsible for all scientific content and direction of the project.

The Digital Astronaut Project