Do Humans Have a Future in Moon or Mars Gravity?

摘要

Before the space age, designers assumed artificial gravity for crewed facilities. Concerns about crew health in microgravity receded after the 2-week Gemini 7 mission. But far longer stays on Skylab, Russian stations, and ISS have uncovered a wide range of health problems, including changes in bones, muscles, eyes, fluids, and immune response. Exercise, diet, and drugs help but do not eliminate these problems. Surprisingly, all 13 solar system bodies with 9% to 250% of earth surface gravity cluster in 3 narrow bands, all near earth, Mars, and Moon gravity. The 4 planets with earth-like gravity, Venus, Saturn, Uranus and Neptune, all pose problems for settlement. The 8 smaller bodies near Moon or Mars gravity all seem far more practical, and also have far lower two-way AVs. Viable plans for settling in Moon or Mars gravity requires that we evaluate the health implications and countermeasures in sustained Moon and/or Mars gravity, on large numbers of people. A rotating "Moon-Mars dumbbell" in LEO can find whether humans can live on the 8 bodies with gravity near Moon or Mars, and possible constraints on later returns to earth gravity. An inflated tunnel can allow crew shirt-sleeve transfers between Moon and Mars levels. Additional tunnels added later can also grow crops, using filtered sunlight and/or LEDs. Such tunnels may also be useful in settlements. The paper argues that ground-based rotating-room tests have different sensory effects, so we don't yet know how fast facilities can rotate without excessive negative crew reactions. We can test rate effects as Gemini 11 did, using crew vehicles on the way to ISS. Rotation tests can determine the diameter and hence minimum mass and cost of rotating free-space settlements. A new test concept allows Moon then Mars gravity in one crew module. A 1-rpm Moon-Mars dumbbell would be ~500 m long. Easy transfer between free-fall, Moon, and Mars gravity levels may attract far more "space tourists" than free-fall-only designs. The