Spacelab

The first United States Microgravity Laboratory (USML-1) flew in orbit inside the Spacelab science module for extended periods, providing scientists and researchers greater opportunities for research in materials science, fluid dynamics, biotechnology (crystal growth), and combustion science. This photograph shows Astronaut Larry De Lucas wearing a stocking plethysmograph during the mission. Muscle size in the legs changes with exposure to microgravity. A stocking plethysmograph, a device for measuring the volume of a limb, was used to help determine these changes. Several times over the course of the mission, an astronaut will put on the plethysmograph, pull the tapes tight and mark them. By comparing the marks, changes in muscle volume can be measured. The USML-1 was launched aboard the Space Shuttle Orbiter Columbia (STS-50) on June 25, 1992.