'Mighty mice' stay musclebound in space, boon for astronauts

'Mighty mice' stay musclebound in space, boon for astronautsBulked-up, mutant “mighty mice” held onto their muscle during a monthlong stay at the International Space Station, returning to Earth with ripped bodybuilder physiques, scientists reported Monday. A research team led by Dr. Se-Jin Lee of the Jackson Laboratory in Connecticut sent 40 young female black mice to the space station in December, launching aboard a SpaceX rocket. In a paper published in the Proceedings of the National Academy of Sciences, Lee said the 24 regular untreated mice lost considerable muscle and bone mass in weightlessness as expected — up to 18%.