It provided data on the reaction of mammal, reptile, insect, fungal, and bacterial forms to prolonged weightlessness.

You are right that scientists on Mir have learned a great deal about the physiological effects of prolonged weightlessness.

This was slightly less than the expected rate, and an encouraging sign for experts who feared that irreversible bone damage might be the result of prolonged weightlessness.

Even the presumed trump card for the station - the opportunity to study the effects of prolonged weightlessness on the health of crew members - has been greatly exaggerated.

The melting was supposed to be a high-gravity alleviant, and might be vulnerable to prolonged weightlessness.

In orbit, they had sacrificed some of their exercise time for the sake of carrying out their scientific work, and their bodies' reactions to the prolonged weightlessness emphasised the importance of maintaining regular exercise.

He was not looking forward to being under gravity again--even less so if he and his comrades suffered more than they had to from the weakened bones brought on by prolonged weightlessness.

Unfortunately, prolonged weightlessness also damages bones and muscles, so the beneficiary of a long voyage might have to spend his or her lengthened life as a cripple.

Not surprising, since, alarmingly, the scientists had discovered one of the effects of prolonged weightlessness was to weaken not only muscles but bones, damaging the bones irreparably.

One of the most worrisome problems of prolonged weightlessness, the loss of calcium from the skeletal system, has been solved by a combination of exercise and medication, he said.