Bone loss is a problem for astronauts spending months or years in space. National Space Biomedical Research Institute scientists are designing a compact machine to allow precision bone and tissue measurements in space.

The advanced multiple projection dual-energy X-ray absorptiometer, called AMPDXA, will measure tissue mass, bone density and bone geometry.

"Knowing these measurements while in space will allow astronauts to either increase exercise or take medications to counter the loss of bone and muscle mass due to long-duration microgravity exposures," said Dr. Harry K. Charles, NSBRI technology development associate team leader and assistant department head for engineering at The Johns Hopkins University Applied Physics Laboratory. "We want to avoid weakened bones that would put astronauts at risk for fractures upon return to Earth or when landing on another planet."

On Earth, this instrument will be a significant advance in the diagnosis, monitoring and treatment of osteoporosis. Portable versions of the machine will make it easier to do screenings for osteoporosis in retirement communities and at nursing homes.