Astronauts Rusty Schweickart (right) and Edward Gibson (left) test emergency procedures to free jammed solar array panels on the Skylab workshop. A metal strap became tangled over one of the folded solar array panels when Skylab lost its micrometeoroid shield during the launch. The astronauts are in the Marshall Space Flight Center (MSFC) Neutral Buoyancy Simulator (NBS) using various cutting tools and methods developed by the MSFC to free the jammed solar wing. This huge water tank simulated the weightless environment that the astronauts would encounter in space.