Between 1993 and 1996, the McDonnell Douglas DC-X, also known as the "Delta Clipper", conducted twelve low-altitude suborbital test launches to verify the configuration and handling of the uncrewed single-stage-to-orbit Delta Clipper design, which was proposed to the United States Department of Defense and the National Aeronautics and Space Administration (NASA) for use as a reuseable launch vehicle.^[1] Claimed as the first rocket to conduct a vertical landing on Earth, the DC-X was a one-third scale demonstrator for the proposed operational Delta Clipper vehicle.^[2]

After the first three flights Strategic Defense Initiative Organization funding for the test project was cancelled;^[3] the remaining test program was conducted by NASA and the Advanced Research Projects Agency.^[4] Following the eighth test flight, the vehicle was transferred fully to NASA and the vehicle was modified to DC-XA configuration,^[5] also known as "Clipper Graham" after General Daniel O. Graham who had died in 1995 after supporting the Delta Clipper project.^[6]

Of the overall test program, ten of the vehicle's launches were fully successful; the fifth test flight was aborted early in the flight following an on-board explosion but the vehicle was successfully recovered. The twelfth and final flight saw one of the vehicle's landing legs fail to extend; on landing, when the vehicle tipped over onto its unsupported corner, a liquid oxygen tank ruptured and exploded, the ensuing fire destroying the modified DC-XA vehicle and ending the program. Despite the loss the program was considered overall to have been a success.^[1]