With a roar audible in the insulated control room, superheated air blasts through the tunnel. A screen above the banks of instruments shows a pressure rake swinging into the flow, its probes quickly glowing white.
Suddenly the test is terminated, a glitch somewhere, but another step closer to the first Mach 6.5 run of the X-1 scramjet in the 8ft (2.4m) High Temperature Tunnel (HTT) at NASA Langley Research Center in Virginia.
Used in the 1960s for re-entry testing, the HTT was upgraded in the 1980s to test engines at speeds from M4 to M7. The tunnel has been used to test the 30%-scale NASP concept demonstrator engine, the X-43A's scramjet, the HyTech ground demonstrator engines and now the X-1.
"When X-43 ended, we did not take all the high-speed competency out of NASA," says researcher Aaron Auslender. Now, under its fundamental aeronautics programme, the agency is collaborating with AFRL on the X-51, providing test services, analysis - and expertise.
"NASA's interest in hypersonics is for air-breathing access to space and high-mass Mars re-entry. The technologies overlap," says Auslender. For the X-51, NASA is contributing extensive computational fluid-dynamics analysis of the air vehicle and all test hours on the X-1 and X-2 engines.
The Woracle: a quick guide to hypersonic programmes
Source: Flight International
