Modern-Aviation

The X-31 Enhanced Fighter Maneuverability Demonstrator was used to test the newest technology in highly maneuverable fighters. The X-31 program logged an X-plane record of 580 flights during the program, 559 research missions and 21 in Europe for the 1995 Paris Air Show. This image was taken in March 1998.

<<< However, due to technical problems with the composite liquid hydrogen tank, the X-33 program was cancelled in February 2001.

he unpiloted X-34 is a technology testbed demonstrator that is designed to demonstrate key vehicle and operational technologies applicable to future low-cost reusable launch vehicles. This image was taken July 20, 2000.>>>

The X-36 was built as a prototype remotely-piloted fighter jet without traditional tail surfaces. It first flew in 1997 and had 31 research flights since then. This image was taken on Oct. 30, 1997.

This artist's conception shows the X-37 Advanced Technology Demonstrator in the Shuttle Payload Bay. The aircraft is designed to test technologies for NASA's space plane program.

The X-38 Crew Return Vehicle (CRV) research project is designed to test a prototype emergency crew return vehicle for the International Space Station. Flight research with the X-38 at Dryden began in 1997 and the aircraft has since completed eight flights. The program was terminated in 2002. This image of a drop test was taken Dec. 13, 2001.

The X-5 was flight tested at the NACA High-Speed Flight Research Station from 1952 to 1955 to test variable sweep wings. The aircraft completed 133 test flights during three years of service. This image was taken in 1957.

The X-43A Hypersonic Experimental (Hyper-X) Vehicle hangs suspended in the cavernous Benefield Aenechoic Facility at Edwards Air Force Base in January 2000. The X-43A was developed to flight test a dual-mode ramjet/scramjet propulsion system at speeds from Mach 7 up to Mach 10.

The Boeing X-45A is being tested by the Joint Unmanned Combat Air Systems (J-UCAS) program as a weaponized unmanned vehicle. This image was taken on April 18, 2004 during a GPS-guided weapon demonstration flight..

A joint NASA/Boeing team tested the X-48B Blended Wing Body aircraft at NASA's Dryden Flight Research Center. The team completed the 80th and last flight of the project's first phase on March 19, 2010.