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  • Do Humans Have a Future in Moon or Mars Gravity?

    Paper number

    IAC-19,D3,1,9,x51638

    Author

    Mr. Joseph Carroll, United States, Tether Applications, Inc.

    Year

    2019

    Abstract
    Surprisingly, all 13 solar system bodies with 9\% to 250\% of earth surface gravity cluster in 3 narrow bands:
     
    \begin{center}5 of 8 planets have 88-115\% of earth gravity,
     
    Mercury and Mars each have 38\% of earth, \&
     
    the 6 largest moons all have 13-18\% of earth. 
    \end{center}
    
    Venus, Saturn, Uranus and Neptune all have earth-like gravity, but pose practical challenges for human exploration or settlement. The 8 bodies near Moon or Mars gravity all seem far more practical, and also have easier two-way access.
     
    Before the space age, designers assumed artificial gravity for crewed facilities. Worries about microgravity receded after the successful 2-week Gemini 7 mission. But far longer stays on Skylab, Russian stations, and the ISS have shown an expanding range of health problems, including changes in bones, muscles, eyes, fluid balance, and immune response. "Countermeasures" help but do not prevent these problems.
    
    But the only crew experience of Moon or Mars gravity is 1-3 days on 6 Apollo missions, and $<$1 minute parabolic flights. Some microgravity changes do not asymptote even after a year, so we may need $>$1 year stays to find the effects of Moon or Mars gravity. Developing realistic plans for either exploration or settlements near Moon or Mars gravity requires that we evaluate the health implications and any needed countermeasures for sustained Moon and Mars gravity, on humans and any ecosystems we develop to support ourselves.
     
    A rotating asymmetrical "Moon-Mars dumbbell" in LEO can clarify our future on the 8 bodies with gravity near Moon or Mars, and limits on later return to earth. An inflated tunnel can allow crew shirt-sleeve transfer between Moon and Mars. Such a tunnel could also grow crops, if it has LED lighting or transmits filtered sunlight. Similar tunnels may even be useful to settlements. A dumbbell can also test rotation rates and hence sizes for free-space settlements, and uses for their reduced gravity regions.
     
    Ground-based crew rotation tests are not exactly relevant, so we don’t yet know how fast a dumbbell can rotate without excessive negative crew responses. But even 1 rpm spin seems ok: a Moon-Mars dumbbell would be 500 m long. Tunnel mass could be $<$10\% of system mass. We can test rotation rates like Gemini 11, using a crewed Dragon 2 on the way to ISS.
    Abstract document

    IAC-19,D3,1,9,x51638.brief.pdf

    Manuscript document

    IAC-19,D3,1,9,x51638.pdf (🔒 authorized access only).

    To get the manuscript, please contact IAF Secretariat.