This photograph was taken in the Marshall Space Flight Center (MSFC) Neutral Buoyancy Simulator (NBS) during the testing of an emergency procedure to deploy a twin-pole sunshade to protect the orbiting workshop from overheating due to the loss of its thermal shield. The spacecraft suffered damage to its sunshield during its launch on May 14, 1973. This photograph shows the base plate used to hold the twin-pole in place, the bag to hold the fabric sail, and the lines that were used to draw the sail into place. Extensive testing and many hours of practice in simulators, such as the NBS, helped prepare the Skylab crewmen for extravehicular performance in the weightless environment. This huge water tank simulated the weightless environment that the astronauts would encounter in space.