Boeing X-40

History

The X-40A was an uncrewed test vehicle built by Boeing to about 80 to 90 percent of the size of the X-37 reusable spaceplane. It had no engines or heat shielding. Boeing Phantom Works in Seal Beach, California, constructed it for the Air Force’s Space Maneuver Vehicle program, working with the Air Force Research Laboratory.

After its first drop test in August 1998, the vehicle went to NASA for modifications. From April 4 to May 19, 2001, it completed seven successful free flights. That same year, it proved the X-37’s chunky, short-winged shape could glide effectively and confirmed the planned navigation system worked.

Testing

The X-40A's first drop test took place on August 11, 1998, at 06:59 over Holloman Air Force Base in New Mexico. A UH-60 Black Hawk helicopter released the vehicle from about 10,000 feet in altitude, roughly 2.5 miles from the end of Runway 04. (Later tests used an Army CH-47D Chinook helicopter.) The craft descended toward the runway in a dive similar to the Space Shuttle's approach, flared, and touched down to the left of the runway centerline.

Its drag chutes opened successfully, and the vehicle corrected its path to within 7 feet of the centerline, coming to a stop after traveling just over 7,000 feet. In 2001, the X-40A completed seven approach and landing test flights at NASA’s Dryden Flight Research Center (now Armstrong) in Edwards, California. These flights aimed to reduce risk for the X-37 program, testing guidance, navigation, and control software for autonomous flight. During one test, an Army CH-47D Chinook helicopter towed the craft to 15,000 feet before releasing it.

The X-40A then executed an autonomously controlled 75-second descent, gliding and guiding itself to a landing on the main runway at Edwards Air Force Base.