The SOFIA aircraft is bathed by water from Air Force Plant 42 fire department trucks, outside its hangar at Dryden's Aircraft Operations Facility in an effort to check for leaks around the telescope cavity door. Even small amounts of moisture would affect the optical performance of the telescope mirrors.
The SOFIA aircraft is bathed by water from Air Force Plant 42 fire department trucks, outside its hangar at Dryden’s Aircraft Operations Facility in an effort to check for leaks around the telescope cavity door. Even small amounts of moisture would affect the optical performance of the telescope mirrors that are hidden beneath the door located in the aircraft’s rear fuselage.
Image credit: NASA/Tom Tschida