The US Air Force (USAF) has canceled its Air-Launched Rapid Response Weapon (ARRW) project, the latest blow to America’s floundering hypersonic weapons program as China and Russia develop a crucial strategic advantage.
Last month, The Warzone reported that the USAF plans to scrap the Lockheed Martin ARRW in favor of Raytheon’s Hypersonic Attack Cruise Missile (HACM) due to a string of ARRW test failures.
The report quotes USAF Assistant Secretary for Acquisition Andrew Hunter, who says that the USAF does not intend to pursue follow-on ARRW procurement. He said the two remaining prototype missiles will be used to gather hypersonic flight data but not lead to further ARRW purchases.
Late last month, South China Morning Post (SCMP) reported on the failed second flight test of the ARRW. It said that although the ARRW was successfully launched from a B-52H bomber off the coast of southern California, with its warhead successfully separating from its booster and continuing flight, the data link transmitting in-flight telemetry information failed.
SCMP says that the data link failure resulted in the loss of data that could have helped the Pentagon understand the ARRW’s flight characteristics and that the flight team behind the test is working to determine whether the failure was caused by a faulty data link or a flaw in the ARRW’s warhead.
The report also said that the failed ARRW test was the second of four planned tests that had aimed to show the weapon had early operational capability and was thus worthy of putting it into production.
The ARRW’s first test succeeded. Last December, Air & Space Forces Magazine noted that the ARRW was launched from a B-52H bomber off the coast of southern California, with the missile accelerating to hypersonic speed, separating from its booster, flying at speeds beyond Mach 5 and detonating in the target area.
Despite that success, the source notes that the ARRW had suffered previously from multiple launch failures.
The ARRW’s failure may be attributed to design flaws and institutional problems within US hypersonic weapons testing procedures.
Asia Times noted in July 2022 that overly complex US hypersonic weapons designs might be the reason for some failures, as the ARRW’s two-stage design may be unnecessarily complicated in its requirement of proper integration of multiple subsystems, resulting in more potential points of failure and requiring more tests for design validation.
Aggressive test schedules unsupported by planning and testing capability and the US’ rush to quickly deploy hypersonic weapons to match China and Russia may have also led to testing failures, which paradoxically has delayed their deployment time.
Poor weapons design and fabrication, poor test planning and management, gaps in preflight tests, lack of rigorous government oversight and a tendency to trivialize costly failures have also likely contributed to the rush to failure.
Air & Space Forces Magazine mentioned that the ARRW is one of the two hypersonic weapons under the USAF’s development to attack urgent, time-sensitive targets, with the other being the HACM.
In contrast to the boost-glide design of the ARRW, wherein rocket boosters propel the weapon to hypersonic speeds before its warhead glides to the target, the HACM is a scramjet-powered air-breathing system.
Air & Space Forces Magazine reported last month that the USAF is now more committed to pushing the HACM program due to the ARRW’s failure. The report also mentions some advantages of the HACM over the ARRW, such as its smaller size, which allows it to be compatible with more types of aircraft including fighters such as the F-15EX. The ARRW, on the other hand, could only be carried by bombers.
The US could also leverage AUKUS to develop the HACM and avoid the pitfalls that grounded the ARRW. Asia Times noted last month that the sharing of highly-sensitive technology such as nuclear propulsion, hypersonic engines and missile defense satellites sets AUKUS apart from other alliances and security blocs, as such only happens in the tightest of alliances.
Australia may become a key US partner in developing the HACM. Last month, Asia Times reported that the US Department of Defense (DOD) chose Australia-based Hypersonix to develop a high-speed hypersonic testbed aircraft.
This partnership aims to address the testing deficiencies in the US hypersonic weapons program, which appear to have led to the failure of the ARRW program.
Hypersonix’s DART AE test aircraft is powered by a hydrogen scramjet that can reach Mach 7 and is designed to test high-speed platforms, components, sensors, communications and control systems.
It also aims to support the US Hypersonic and High-Cadence Airborne Testing Capabilities (HyCAT) program, which seeks to enlist the aid of the private sector and military users to reduce the strain on US hypersonic testing facilities.
Moreover, the HACM may feature Australian hypersonic engine technology. Asia Times reported in April 2022 that Hypersonix presented its 3D-printed scramjet engine to senior US officials the previous month, with its design appearing to have several advantages over US systems.
For example, Hypersonix claims that its engine can be printed in three weeks using special alloys. The company intends to use more exotic coatings for hypersonic flight control surfaces, which endure extreme temperatures during flight.