The 8-Foot High-Temperature Tunnel (HTT) is the nation’s largest hypersonic blow down test facility. The facility supports large-scale thermal protection system testing, flight qualification testing, and hypersonic engine testing. The HTT duplicates as near as possible the flight conditions that would be encountered by hypersonic vehicles in the atmosphere. The facility currently provides testing capability at Mach 3, 4, 5, and 6.5. The facility has been heavily utilized for hypersonic engine testing and has tested the National Aerospace Plane Concept Demonstration Engine, the X43 Hyper-X engine, the Office of Naval Research HyFly Dual Combustor Ramjet Engine, the X43C program’s Ground Demonstrator Engine No. 2, and the Air Force Research Laboratory SJX61–1 and SJX61–2 engines.
8-Foot High Temperature Tunnel Fact Sheet