The Dassault HU-25C Guardian is a modified twin-engine business jet, based on the civilian Dassault FA-20G Falcon. The aircraft was previously used by the U.S. Coast Guard as a search-and-rescue platform. NASA acquired this aircraft in 2011 to provide a medium altitude, medium range platform for remote sensing instruments and satellite support. Payload accommodations include a nadir camera port, large search windows on each side of the fuselage, a hard point with pylon under each wing, provisions for mounting atmospheric sampling probes on the crown of the fuselage, and a nadir drop hatch (32 in. long x 19.7 in. wide).