The second flight test of an X-51A experimental hypersonic air vehicle was cut short when the vehicle’s scramjet engine ignited but did not transition to full power, announced Air Force officials Wednesday. “Obviously we’re disappointed and expected better results,” said Charlie Brink, Air Force Research Lab’s X-51A program manager, of Monday’s test off of the coast of California. “But we are very pleased with the data collected on this flight.” A B-52 released the X-51 at about 50,000 feet in altitude; the X-51’s booster then accelerated the vehicle to a speed around Mach 5 before it separated. While the vehicle’s scramjet engine subsequently lit on ethylene, it did not properly transition to JP7 fuel operation, said the officials. The vehicle then continued on in a controlled orientation until ocean splashdown. The first X-51 flight, considered overwhelmingly successful, took place in May 2010. The next flight test is tentatively scheduled for the fall.
More than 100 B-21s will be needed if the nation is to avoid creating a high demand/low capacity capability, panelists said on a Hudson Institute webinar. The B-21's flexibility, stealth, range and payload will be in high demand for a wide range of missions, both traditional and new.