CHAPEL HILL, N.C., July 5 (UPI) -- An experiment to learn more about bone loss in astronauts exposed to weightlessness will go aloft on NASA's final shuttle flight, U.S. researchers say.
Scientists at the University of North Carolina and North Carolina State University are sending 30 mice into orbit on the shuttle Atlantis as a part of research on bone and muscle health in microgravity, a UNC release said Tuesday.
Rapid bone loss results from removing gravitational loading and will be unavoidable on interplanetary missions such as a round trip to Mars, researchers said.
"We've known for quite a while, since the 1970s and the Skylab missions, that astronauts are going to lose bone on these extended missions," Ted Bateman of the schools' Joint Department of Biomedical Engineering said. "Comprehensive work has been done to identify the amount of loss -- about one to two percent per month, which is approximately five times the rate that postmenopausal women lose bone here on Earth.
"On extended missions, beyond six months up to three years, such as on a Mars mission, this loss is going to be substantial."
The Atlantis experiment will study how weightlessness in space affects mouse bone tissue at the molecular level, the researchers said.