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