A 5.9 percent scale model of NASA’s Orion Multi-Purpose Crew Vehicle atop a United Launch Alliance (ULA) Delta 4 rocket was recently tested in a transonic wind tunnel at the U.S. Air Force’s Arnold Engineering Development Center (AEDC), the Tennessee-based research facility announced April 6.

A ULA team led by senior staff engineer Mike Schoonmaker used AEDC’s 4.9-meter transonic wind tunnel to gather dynamic pressure and steady state pressure data in preparation for Exploration Flight Test (EFT)-1. Scheduled for launch in September 2014, the flight test involves launching an unmanned Orion atop a Delta 4 some 5,600 kilometers into space to test the crew capsule’s ability to survive the kind of high-speed re-entry it will perform when NASA’s Space Launch System heavy-lift rocket launches the spacecraft on a circumlunar trajectory in 2017.

“The Delta IV Heavy vehicle is a flight-tested configuration, but every time a new geometry is put on the front end, ULA must verify flight margins,” Schoonmaker said in a statement. “The new element in this case, Orion, has not flown yet, but Orion models have been tested in other wind tunnels; thus, these new data are really to support whole vehicle buffet modeling and response predictions. This data supports the first engineering test flight of Orion on Delta IV, EFT-1.”