Even though astronauts exercise everyday while they're aboard the International Space Station (ISS), they still experience a fairly significant loss of muscle mass. So much so that they require physiotherapy once they return to Earth. However, researchers with the Houston Methodist Research Institute and the Novartis Institute for Biomedical Research are testing a device that can continuously administer a medicine that may help prevent muscle deterioration, Seeker reports. The team sent 40 mice to the ISS in December, some with devices that deliver the drug and some with devices that just deliver an inactive solution. Half returned to Earth in January and the other half will do so this month.