WHAT HAPPENS TO A PERSON TRAVELING IN SPACE? The zero-gravity environment of space offers many challenges to astronauts. One of them is bone and muscle loss. With no gravity to pull people down, there's no need to use muscles and bones to hold the body upright. Both systems weaken, which is why NASA established exercise programs for astronauts spending long periods of time in the International Space Station. Despite these efforts, astronauts still lose muscle strength and bone density, which is why they require physical therapy on Earth after lengthy stays in orbit.
The Institute of Electrical and Electronics Engineers, Inc.-USA, contributed to the information contained in the TV portion of this report.