Mars Mice

In 2006 a group of mice-astronauts will orbit Earth inside a spinning spacecraft. Their mission: to learn what its like to live on Mars.

Humans need gravity. Without it, as astronauts have vividly demonstrated, our bodies change strangely. Muscles lose mass, and bones lose density. Even the ability to balance deteriorates.

From long experience on the space shuttle and various space stations, we have some knowledge of how mammals, especially people, respond to 0-g. We have even more experience with 1-g on Earth. But we still don't know what happens in between.

What, for example, will happen to humans on Mars where the surface gravity is 0.38-g? Is that enough to keep human explorers functioning properly? And, importantly, how easily will they readapt to 1-g, once they return to Earth?

A team of scientists and students from the Massachusetts Institute of Technology (MIT), the University of Washington, and the University of Queensland, in Australia, plans to explore these questions. They're going to do it by launching mice into orbit.

"What we're doing," explains Paul Wooster, of MIT, and program manager of the Mars Gravity Biosatellite project "is developing a spacecraft that is going to spin to create artificial gravity." The satellite will spin at the rate of about 34 times each minute, which will generate 0.38-g - the same as gravity on Mars.

The team hopes to launch the Biosatellite in 2006. The mice will be exposed to Mars-gravity for about five weeks. Then, says Wooster, they'll return to Earth alive and well. The mice will descend by parachute and land near Woomera, Australia, inside a small capsule reminiscent of NASA's old Apollo capsules.

The Biosatellite project is the first investigation conducted at this gravity level, says Wooster. Financed in part by NASA, the project is also unique "due to the heavy involvement of students in all aspects of the work, including planning the science, designing the spacecraft, raising the funds, and managing the overall effort," he adds.

The research will focus on bone loss, changes in bone structure, on muscle atrophy, and on changes in the inner ear, which affects balance. "The main thing we're trying to do," says Wooster, "is to chart a data-point between zero-gravity and one-gravity."

Credit: MarsGravity.org An artist's rendering of the Mars Gravity Biosatellite in Earth orbit.

As they orbit the earth, the mice, each in its own tiny habitat, will be painstakingly observed. Each habitat will have a camera, so that the researchers can monitor mouse activity. Each will have its own pump-driven water supply, so that each mouse's water consumption can be tracked.