Once upon a time, people sent monkeys and dogs into the stratosphere as test subjects aboard rockets we weren't yet willing to put a human being on top of. We also used mice to gauge how microgravity was likely to affect humans, as seen in the old video clip above.
Today, animals still go into space, but for very different reasons. And NASA's top veterinarians have developed far more stringent guidelines governing how research animals in space can be treated. The rules are aimed at finding a good balance between the desire to be humane, the need to dissect most of the creatures that do go into space, and the constraints of working in a cramped environment.
NASA's use of animal astronauts has changed along with the culture, according to Dunlap. "We've become more compassionate with time, more aware of seeing and making sure that animals get humanely treated." The agency is unlikely ever to return to the days of flying monkeys and chimpanzees. Other than humans, mice are the highest-order animal currently being sent into space. They provide the best balance of sample size (more tissue and bone structure to study) and cage logistics: their small cages are easier to store in a cramped cabin and to provide with ample air circulation.
The mice brought back this summer on Atlantis were part of a medical study by pharmaceutical company Amgen that uses weightlessness to look at bone loss, which is worsened by the absence of gravitational stress on the skeleton. Most animal research in space is geared toward using analogous animal physiology to extrapolate the effects of microgravity on astronaut health. Amgen also hopes to use the mouse study to improve its osteoporosis drugs used on Earth.
Animals can spend months living in space before returning to Earth for analysis. Most are tucked away in experiment racks that are stowed like drawers. The crew only has to check on the animals once a day to make sure they're healthy. But if the animals become sick in orbit, there's little the crew members can do. "We have looked into trying to fly veterinary kits to treat animals," says Dunlap. "But it just becomes problematic, because if you have syringes and needles that you would use to treat an animal, then the safety folks get concerned. They don't want a crew member getting stuck or bitten."
(Via Heather Gross)