First test of hypersonic Waverider jet in May 2010
15 August 2012 Last updated at 10:42 BST
The US military has conducted a test flight of its hypersonic jet Waverider, aiming to reach Mach 6 (4,300mph; 6,900km/h) above the Pacific Ocean.
This archive footage, taken in May 2010, shows the jet in action.
Courtesy US Department of Defense and Pratt & Whitney