Looking out from inside the enormous mouth of NASA's giant thermal vacuum chamber, called Chamber A, located at NASA's Johnson Space Center in Houston, the Pathfinder or test model of the James Webb Space Telescope's backplane is seen sliding in on the rails.

Previously used for manned spaceflight missions, this historic chamber is now being readied for a cryogenic test.

"After over a decade of planning, it is gratifying to see everything coming together so smoothly," said Lee Feinberg, NASA Optical Telescope Element Manager.

Prior to this shot, the entire Pathfinder was manually deployed, lifted and installed on a cart.

"This is a huge milestone. There were three organizations working together to make this happen," said John Amon, Manufacturing Engineer for Exelis Rochester, New York, "NASA, Northrop Grumman and Exelis had a strong collaboration. This move is really moving the Pathfinder testing forward."

Once the cart was ready the Pathfinder traveled down the rails into the chamber. This is the Pathfinder's fit check, the first time it has entered the chamber.

Afterwards, Pathfinder was taken out and the next time it returns into the chamber the giant door will be closed and the cryogenic test is readied.