Hypersonic test flight on track

First flight of the X-51A scramjet demonstrator is now on track for early December while captive carriage tests on the NASA-operated B-52H mothership at Edwards Air Force Base, Calif., are set to begin in October.

A joint effort by the U.S. Air Force, Defense Advanced Research Projects Agency (DARPA), Pratt & Whitney Rocketdyne, and Boeing, the hypersonic vehicle is designed to be the first air-breathing craft to demonstrate sustained speeds in excess of Mach 4 using a “logistically friendly” hydrocarbon fuel.The initial vehicle is the first of four X-51As to be launched by April 2010.

First flight, targeted for December 2008 under the original schedule, was later reset for early in the fourth quarter of 2009. But integration issues with the B-52H mothership, along with logistic delays, pushed the first flight target toward late November.The target date has now been moved to Dec. 3

Rolling upright, the X-51A is expected to cover almost 400 miles in five minutes and reach an altitude of around 100,000 feet before the fuel is exhausted and the vehicle ditches in the Pacific test range off southern California.