Freakish Speed, by the Numbers

by NASA NASA

5,000 MPH Approximate top speed clocked by the X-43A hypersonic scramjet aircraft on March 27


720 MPH Relative speed of sound


11 SECONDS Approximate duration of the X-43A’s powered flight


15 MILES Distance traveled


2 HOURS Estimated flight time from New York to Hong Kong traveling 5,000 mph


1 MILLISECOND Time the X-43A engine takes to generate thrust


2,200 MPH Previous record for a jet aircraft


1,350 MPH Average cruising speed of Concorde jet


4,000â€4,500 F Temperature inside a scramjet engine


2,500â€2,700 F Melting point of steel


6,750 MPH Anticipated speed of NASA’s third and final X-43A hypersonic aircraft, scheduled to fly this fall


Source: NASA