Rodents and a rocket carried these researchers` dreams to space
(PHYSorg.com Space & Earth)

The human body evolved within the constant force of Earth`s gravity. To prevent bone and muscle atrophy during their stays in space, astronauts must exercise every day. For researchers studying bone or muscle loss that might be caused by diseases, aging or a sedentary lifestyle, the microgravity environment aboard the International Space Station is a unique place to perform experiments that can help us understand how the body works.