‘Mighty Mice’ Stay Musclebound in Space, Boon for Astronauts

A normal mouse and a “twice-muscled” mouse developed at the The Jackson Laboratory of the University of Connecticut School of Medicine in Farmington, Conn., in August 2020. Dr. Se-Jin Lee/University of Connecticut School of Medicine via AP

CAPE CANAVERAL, Fla.—Bulked-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.

The findings hold promise for preventing muscle and bone loss in astronauts on prolonged space trips like Mars missions, as well as people on Earth who are confined to bed or need wheelchairs.