After designing a protective parasol to cover the Skylab Workshop, crews needed to practice using specially designed tools and materials to facilitate the repair procedure. Marshall Space Flight Center's Neutral Buoyancy Simulator (NBS), was used to practice these maneuvers. Pictured here are the astronauts in the NBS deploying the “twin pole” solar sail protective cover on the Apollo Telescope Mount, and solution that was eventually replaced the solar parasol after the success of the Skylab 2 mission.