![]() Mars Mouse does a few laps for future muscle 3MB Mpeg |
Coriolis forces are a secondary byproduct of rotating artificial gravity systems. It has long been argued by advocates of zero-gravity space travel that such forces would prove disorienting to astronauts, especially at rotation rates above 4 revolutions per minute.
The Mars Society's Translife Mission will place a group of mice in low Earth orbit for about 50 days in a rotating spacecraft that will supply them with artificial gravity at Mars levels, 38% that of the Earth. During this time, the mice will be allowed to reproduce and the young will grow up in Martian gravity.
Subsequently, the capsule will be recovered and the mice and their descendants studied. The mission will thus serve as a key experiment to determine whether artificial gravity at Mars levels can be used as a countermeasure against the well-known debilitating effects of zero-gravity spaceflight, and to determine whether mammals from Earth can develop satisfactorily if conceived, born, and raised in Mars gravity. This question is central to the issue of whether humans can ever settle Mars, or any other planet with gravity substantially less than that of the Earth.
In order to keep the size of the Translife spacecraft small, however, the rotation rate must be high. In particular, for the 1 m diameter capsule currently under consideration, the rotation rate must be about 25 rpm. This has caused some to raise concerns that the Coriolis forces would be so excessive as to disorient the mice and ruin the experiment.
In order to resolve these concerns, an experiment was constructed consisting of a mouse habitat positioned on the edge of a turntable rotating at 25 rpm. This system thus creates 0.38 g in the outward direction, which combines with a 1 g downward acceleration imposes a total g-load of 1.07 g's on the mice. While this is different from the 0.38 g they would experience in this system on orbit, the Coriolis force is the same.
The system was started on Wednesday, August 30, 2001. Behavior of the mice immediately after start up was observed to be completely normal, that is to say, indistinguishable from their behavior before the cage was rotated. The experiment has continued since that time operating 24 hours a day, 7 days a week. The mice have been observed to forage, groom, drink, eat and sleep. As of Sept 18, their behavior is still normal and their health is fine.
Commenting on the experiment, Mars Society president Dr. Robert Zubrin said; "These results clearly show that the concerns raised by zero-gravity spaceflight advocates over Coriolis forces have been greatly overdrawn. They show that small low-cost long-duration artificial gravity experiments with mammals are completely feasible.
"Given the consistent record of failure to find adequate counter measures to debilitation of bone and muscle systems during zero gravity, these results underscore the need for expanded research in artificial gravity spaceflight systems. Humanity is not going to the stars in zero gravity. We need to find alternatives. The Translife Mission will show the way."
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Brisbane - Sept. 19, 2001