Researchers from Boeing Phantom Works and the Air Force Research Laboratory have used a rocket sled in combo equipped with "active flow control" to release a smart bomb known as MK-82 Joint Direct Attack Munition Standard Test Vehicle (JDAM) at a speed of about Mach 2 from a weapons bay with a size approximating that of the U.S. Air Force B-1 bomber.

Active flow control is a tandem array of microjets upstream of the weapons bay that, when fired reduces the unsteady pressures inside the bay and modifies the flow outside to ensure the JDAM munition travels out of the bay correctly.Boeing said wind tunnel testing indicated that without active flow control, the JDAM munition would have returned to the bay. The release of the test vehicle from the rocket sled bay was a bigger challenge than an equivalent release from an aircraft bay at altitude, due to the reduced dynamic pressure, reduced vibration and increased amount of time in which to release a munition, Boeing said.

Boeing also noted that the rocket sled used to test active flow control was a record setter on its own. The sled used in the High Frequency Excitation Active Flow Control for Supersonic Weapon Release (HIFEX), at 65,700 pounds, was 26,000 pounds heavier than any sled tested in more than 10 years but was faster by 400 feet per second. In the 57-year history of the Holloman High-Speed Test Track, it was the heaviest sled train to reach Mach 2," Boeing said.