Two years prior to being used during a shuttle mission, the Transfer to Orbit System (TOS) is being demonstrated at Marshall Space Flight Center's (MSFC) Neutral Buoyancy Simulator (NBS). TOS is an upper stage launch system used to place satellites into higher orbits. TOS was used only once, on September 12, 1993 when the Space Shuttle Discovery (STS51) deployed ACTS (Advanced Communications Technology Satellite). The test pictured was to provide an evaluation of the extravehicular activity (EVA) tools that were to be used by future shuttle crews.