Our Problem is bone density loss in space.

A survey of13 space station astronauts found that their bone strength dipped by at least 14 percent on the average during their half-year stays aboard the orbiting laboratory.

Three of the astronauts lost up to 30 percent of their bone strength during their long-duration spaceflights, putting them on par with the bone strength of older women with osteoporosis on Earth, the study reported.

?Ifpreventive measures are not taken, some of our astronauts may be at increased risk for age-related fractures decades after their missions