High Bay Clean Room

This clean room is also known as the Hubble Space Systems Development and Integration (SSDIF) Facility, the world's largest clean room.

The tour included a stop at an observation balcony overlooking the clean room (the window to this observation gallery is visible in the upper right of this picture).

When we visited, they were preparing for Hubble Servicing Mission 4. It contains both instruments being prepared for the servicing mission and mockups of the HST, used to verify component fit. The clean room is also used by astronauts to train for the servicing mission itself.

Goddard's web site features an interactive panorama of this facility.

Another NASA site includes additional information about the clean room and its contents.