The Air Force is resurrecting its boost-glide missile program—an effort first launched to much fanfare in August 2018, only to see mixed results in testing and ultimately lose support from service leadership amid investment in alternative missiles.
The AGM-183A Air-Launched Rapid Response Weapon, or ARRW, is one of two hypersonic concepts the Air Force is developing now, service head Gen. David Allvin told lawmakers Thursday. “You will see [them] in the budget submission, assuming it’s what we had put forward,” he said, also hinting at two other classified systems currently in testing.
The Air Force first awarded Lockheed Martin a $480 million contract in 2018 to begin testing the ARRW. The missile is what’s called a boost-glide system: It reaches near-space altitudes using a rocket booster, then glides back to Earth at speeds exceeding five times the speed of sound (Mach 5). Unlike conventional ballistic missiles, modern boost-glide weapons can maneuver in flight, making them nearly impossible to intercept with existing missile defense systems.
The Air Force also continues to invest in the Hypersonic Attack Cruise Missile, or HACM, which uses a scramjet engine. Scramjets compress incoming air using the vehicle’s speed—also above Mach 5—mixing it with fuel and igniting it while in flight. The result is propulsion that’s efficient at hypersonic speeds and, like boost-glide systems, difficult to defend against. Scramjet-powered cruise missiles fly lower and maneuver more flexibly than their boost-glide counterparts, but they are slower. More importantly, the underlying technology has been demonstrated for more than two decades, making building them a less daunting technical challenge.
ARRW’s performance in tests was mixed, and in March 2023, then-Air Force Secretary Frank Kendall said he was “more committed” to HACM than to ARRW. The Air Force declined to ask for funding for it the following year.
So why is ARRW back?
Tom Karako, director of the Missile Defense Project at the Center for Strategic and International Studies, said both missile types have advantages—which is why both China and Russia are developing them.
“We’re going to need high-speed maneuvering strike capability that is coming from multiple domains,” he told Defense One.
The more recent tests were reassuring, he said, although the Air Force did not discuss them publicly. “The vibes were that later tests turned out to be better than expected.”
While the Army and Navy are also developing their own hypersonic systems, Karako said the bottom line is that having more options is better than fewer—especially given the edge potential adversaries already hold.
“Diversity imposes costs on the adversary looking in multiple directions at once,” he said.
