The pathfinder aircraft for space shuttle Discovery's ferry flight pulls up beside the Shuttle Carrier Aircraft on the tarmac of the Shuttle Landing Facility.

The “pathfinder” aircraft for space shuttle Discovery’s ferry flight pulls up beside the Shuttle Carrier Aircraft on the tarmac of the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida.

The NASA C-9 aircraft will fly about 100 miles ahead of Discovery to scout for the safest route between destinations. Its crew includes an SCA flight engineer who studies the weather patterns along the flight path to find a route free of rain and other turbulence. The carrier aircraft, also known as an SCA, is a Boeing 747 jet, originally manufactured for commercial use which was modified by NASA to transport the shuttles between destinations on Earth. NASA 905 is scheduled to ferry Discovery to the Washington Dulles International Airport in Virginia on April 17, and is assigned to all remaining ferry missions, delivering the shuttles to their permanent public display sites. After its arrival at Dulles, Discovery will be placed on display in the Smithsonian's National Air and Space Museum Steven F. Udvar-Hazy Center on April 19. For more information on the SCA, visit http://www.nasa.gov/centers/dryden/news/FactSheets/FS-013-DFRC.html. For more information on shuttle transition and retirement activities, visit http://www.nasa.gov/transition. Photo credit: NASA/Amanda Diller