The Space Platform was first conceived as a launching site for deep space exploration. The original idea was to build this space platform either on the moon's surface or near lunar orbit. It would be used as a staging base, where the reusable launch vehicles (later known as Space Shuttles) would ferry machinery and equipment to assemble deep space exploration vehicles. Replaced by the Space Station concept, the space platform idea was never completed. However, early in the space platform development, astronauts trained at the Marshall Space Flight Center's (MSFC) Neutral Buoyancy Simulator (NBS), as pictured here, working on solar array equipment. This experiment was deployed from the shuttle to study the motions of large structures in space. Similar arrays will be used on the Space Station and large observatory spacecraft in the future.