Spacelab

While instruments on the pallets in the payload bay observed the universe, biological experiments were performed in the middeck of the Shuttle Orbiter Challenger. Studying life processes in a microgravity environment can shed new light on the functioning of biological systems on Earth. These investigations can also help us understand how living organisms react to prolonged weightlessness. One such experiment was the vitamin D metabolites and bone demineralization experiment. This investigation measured the vitamin D metabolite levels of crew members to gain information on the cause of bone demineralization and mineral imbalance that occur during prolonged spaceflight as well as on Earth. Research into the biochemical nature of vitamin D has shown that the D-metabolites play a major role in regulating the body's calcium and phosphorus levels. One major function of the most biologically active vitamin D metabolite is to regulate the amount of calcium absorbed from the diet and taken out of bones. This investigation had two phases. The first was the developmental phase, which included extensive testing before flight, and the second, or final phase, involved the postflight analysis of the crew's blood samples. This photograph shows astronaut Story Musgrave in the middeck of the Shuttle Orbiter Challenger, attending to the blood samples he collected from crew members for the experiment.