The single McDonnell Douglas DC-X flight article made eight tests in its original configuration before conversion into NASA’s DC-XA, also known as Clipper Graham. Its four 1996 flights demonstrated lightweight tanks, upgraded reaction control and a 26-hour turnaround. A landing-leg deployment failure on 31 July 1996 caused the article to fall over and burn. The DC-X and DC-XA histories describe successive configurations of this same physical vehicle.