The U.S. Air Force halted the launch sequence for the first planned booster flight test of a prototype Lockheed Martin [LMT] AGM-183A hypersonic Air-launched Rapid Response Weapon (ARRW) aboard a B-52H bomber from Edwards AFB, Calif. on Apr. 5.

“The Air Force had a setback in demonstrating its progress in hypersonic weapons on April 5 when its first booster vehicle flight test encountered an issue on the aircraft and did not launch,” the service said on Apr. 6.

The B-52H was to launch the first ARRW booster test vehicle over the Point Mugu Sea Range, but “the test missile was not able to complete its launch sequence and was safely retained on the aircraft which returned to Edwards AFB,” per the Air Force.

Last December, the Air Force acquisition office (SAF/AQ) said that it expected the first booster flight test of ARRW by the end of 2020 (Defense Daily, Dec. 22, 2020). SAF/AQ also said at the time that the Air Force is looking to begin ARRW production this year but is uncertain of the first production amounts. The Air Force has intended to make ARRW the first fielded hypersonic weapon in the U.S. military.

On Dec. 19 last year, ARRW had its sixth instrumented measurement vehicle (IMV) flight test on a B-52H from Edwards.

IMV testing measures the effect of temperatures and vibration on the missile and communications between the missile and the aircraft.

Air Force goals for the Apr. 5 test included “demonstrating the safe release of the booster test vehicle from the B 52H as well as assessing booster performance, booster-shroud separation, and simulated glider separation,” the Air Force said. “The 419th Flight Test Squadron and the Global Power Bomber Combined Test Force, both at Edwards AFB, Calif., were involved in the testing.  Since the vehicle was retained, engineers and testers will be able to explore the defect and quickly return the vehicle back to test.”

Lockheed Martin referred questions on the shutdown of the Apr. 5 ARRW launch sequence to the Air Force and declined to comment “due to the classified nature of the program.” ARRW is to fly at speeds between Mach 6.5 and 8.

Challenges for hypersonic flight above 50,000 feet include equipping sensors and electronics to withstand the heat, friction, and air resistance created by hypersonic flight; developing advanced materials for such flight; maneuverability to overcome the defenses of adversaries; and continuous connectivity with operators and decision-makers.

Such hypersonic weapons are to be capable of striking time-sensitive, high-priority, and heavily defended targets within 15 minutes. The weapons are to get around the problem of surface-to-air missile threats against manned aircraft and the problem of securing basing rights for such aircraft.

“While not launching [on Apr. 5] was disappointing, the recent test provided invaluable information to learn from and continue ahead. This is why we test,” Air Force Brig. Gen. Heath Collins, the Program Executive Officer for the Air Force’s Armament Directorate, said in a statement.