This 1970 photograph shows the Rotating Litter Chair, a major component of Skylab's Human Vestibular Function experiment (M131). The experiment was a set of medical studies designed to determine the effect of long-duration space missions on astronauts' coordination abilities. The M131 experiment tested the astronauts susceptibility to motion sickness in the Skylab environment, acquired data fundamental to an understanding of the functions of human gravity reception under prolonged absence of gravity, and tested for changes in the sensitivity of the semicircular canals. Data from this experiment was collected before, during, and after flight. The Marshall Space Flight Center had program management responsibility for the development of Skylab hardware and experiments.