NASA Prepares Webb Telescope Pathfinder for Famous Chamber

Engineers and technicians manually deployed the secondary mirror support structure (SMSS) of the James Webb Space Telescope's Pathfinder backplane test model, outside of a giant space simulation chamber called Chamber A, at NASA's Johnson Space Center in Houston. This historic test chamber was previously used in manned spaceflight missions and is being readied for a cryogenic test of a Webb telescope component. In the weightless environment of space, the SMSS is deployed by electric motors.