 Arguably the most persuasive demonstration of the X-35's capability was the final qualifying Joint Strike Fighter flight trials, in which the X-35B STOVL aircraft took off in less than 500 feet (150 m), went supersonic, and landed vertically – a feat that Boeing's entry was unable to achieve.The contract for System Development and Demonstration (SDD) was awarded on 26 October 2001 to Lockheed Martin, whose X-35 beat the Boeing X-32.One of the main reasons for this choice appears to have been the method of achieving STOVL flight, with the Department of Defense judging that the higher performance lift fan system was worth the extra risk.