US hypersonic missile program in crisis or transition?

The AGM-183 Air-Launched Rapid Response Weapon (ARRW) project, the US military’s counter to China and Russia’s rival, more advanced hypersonic missile programs, has received new funding despite earlier signs of cancellation due to poor test results.

This month, The War Zone reported that the US Air Force awarded defense contractor Lockheed Martin an additional US$13.4 million for the ARRW.

The report suggests the funds could be for winding down the ARRW or accelerating a related follow-on program known as the Tactical Boost Glide (TBG), signaling a possible classified evolution or adaptation of the ARRW program. The funding bump raises Lockheed Martin’s ARRW contract’s total value to over $1.3 billion.

The ARRW is a hypersonic boost-glide vehicle that employs a rocket booster to propel an unpowered glide vehicle to hypersonic speeds exceeding Mach 5, making it difficult for adversaries to detect, track and intercept.

The TBG program is a joint DARPA-Air Force effort to enable air-launched tactical range hypersonic boost-glide systems that can be launched from current platforms, according to Pentagon documents cited by The War Zone. The program will also consider traceability, compatibility and integration with the US Navy’s Vertical Launch System, it said.

The ARRW, estimated to cost between $14.9 and $17.5 million per unit, is considered crucial for countering heavily defended, high-value targets such as critical air defense and other command and control nodes, including ones housed in hardened facilities. Because of its high costs, the ARRW would only be fielded in relatively small numbers.

However, the Arms Control Association (ACA) reported in November 2023 that the ARRW faced termination in fiscal year 2024 due to repeated live-fire testing failures. The US Senate and House of Representatives versions of the 2024 National Defense Authorization Act eliminated the $150 million requested for its continued development.

The ACA report said that the program’s setbacks had led to delays in procurement initially planned for 2023. These issues highlighted general disorganization and the lack of a coherent strategy for developing the hypersonic weapons needed to compete with China and Russia. The program’s “final” cost has been reported at $1.7 trillion.

In a July 2024 National Defense Magazine article, Josh Luckenbaugh notes how America’s hypersonic weapon program lags behind China, which boasts the world’s leading hypersonic arsenal, and Russia, which has deployed three hypersonic systems and used them in battle against Ukraine.

Luckenbaugh highlights China’s extensive investment in hypersonic research and infrastructure over the past two decades, including numerous wind tunnels. That, Luckenbaugh says, contrasts with US hypersonic expertise, which has deteriorated since the end of the previous Cold War and now resides mostly in academia, not industry.

Despite the US Air Force’s 2025 budget’s exclusion of additional ARRW funding, the program continues with planned flight tests, including a significant demonstration over the Western Pacific in March 2024. That’s likely due to rising US concerns about China’s hypersonic-bolstered anti-access/area denial (A2/AD) capabilities.

The US Air Force may now be using the ARRW program to validate technologies, techniques and procedures for achieving sustained hypersonic flight, performing safe separation from launch aircraft and collecting data and telemetry that could inform other classified and future US hypersonic weapon projects.

The US’s apparent strategic shift toward air-breathing designs such as the Hypersonic Air-breathing Weapon Concept (HAWC) missile, which the US Air Force said it preferred over the ARRW in March 2023, may lead to more cost-effective, versatile solutions, potentially avoiding the costly complexities of the ARRW’s boost-glide system.

In April 2022, Breaking Defense reported that air-breathing hypersonic weapons, which have no moving parts, offer significant advantages over boost-glide systems.

Because the HAWC operates within the atmosphere, it reduces the need for exotic materials to withstand the extreme temperatures experienced by boost-glide systems and thus lowers production costs. The feature also allows for deployment on a broader range of platforms, including fighters and bombers.

In contrast to air-breathing hypersonic weapons, Asia Times noted in April 2023 that the ARRW’s boost-glide design, which requires the careful integration of multiple subsystems, could contribute to test failures. This complexity could also lead to more points of failure and necessitate additional testing for design validation.

Moreover, an August 2024 US Congressional Research Service (CRS) report says that boost-glide systems do not travel faster than traditional ballistic reentry vehicles despite their unpredictable flight paths complicating missile defense.

The CRS report says that while boost-glide systems can evade some missile defenses due to their maneuverability, they suffer from overall speed limitations.

It also mentions that US hypersonic weapons research focuses mainly on conventional warheads, requiring higher precision compared to China and Russia’s nuclear-armed counterparts and thus increasing the technical complexity of the weapon’s development.

Air-breathing hypersonic cruise missiles may offer more practical, versatile and cost-effective solutions to competing with China and Russia, influencing US hypersonic weapon development and deployment strategies.

The US’s apparent emerging preference for air-breathing hypersonics over boost-glide designs will thus likely have broad implications for its future defense procurement and development.