Falling behind in the hypersonic race, the United States faced setbacks yet again after the “failed trial” of its cutting-edge weapon earlier this month.

The race to produce the most sophisticated hypersonic technology rose to prominence in the last decade. With Russia leading the competition and China closely following behind, the US has been striving to catch up, activating its hypersonic weapons programs across its defense sector. Among which is the US Air Force’s Air-launched Rapid Response Weapons (ARRW) program.

However, the program has been revealed to be “in jeopardy” after its latest failed test.

During this week’s defense hearing, US Air Force secretary Frank Kendall disclosed that the second round of testing of the ARRW on March 13 was unsuccessful.

Likewise, Kendall noted that the ARRW effort “struggled a little bit” throughout its testing phase and that the service may reconsider whether to continue including the initiative in the fiscal year 2025 budget.

Kendall also stated that the service might shift its focus to another hypersonic program, the Hypersonic Attack Cruise Missile (HACM), if the testing process of the ARRW continues to stumble.

What Went Wrong?

According to its press release, the US Air Force conducted the second All-Up-Round AGM-183A ARRW test flight on March 13 off the southern California coast via B-52H Stratofortress.

The second test evaluated the full prototype operational hypersonic missile, focusing on the ARRW’s end-to-end performance. While the test accomplished several objectives, Kendall said the data collected failed to provide the team engineers and testers with what they needed.

The team is now examining what happened, and once determined, “we’ll probably have to make a decision on the fate of ARRW,” Kendall added.

The Air Force did not disclose any further information, citing operational security.

Nevertheless, the service still has two remaining ARRW missiles that it can use for another round of evaluation before making a final decision.

“They have two more test articles that we can use, and we’ll probably have to make a decision on the fate of ARRW after we complete the analysis and hopefully do those two tests,” the secretary said.

Hypersonic ARRW Program

Built by Lockheed Martin, the AGM-183 ARRW is a boost-glide air-to-ground missile capable of soaring through its target up to a maximum speed of more than Mach 5, or five times the speed of sound. Its designated launching platform is aboard B-52H Stratofortress, but likewise can be integrated with B-1B Lancer and F-15E Strike Eagle.

Since the program launched in the mid-2010s, the ARRW has reportedly struggled during the testing phase. Launching its prototype version alone faced setbacks, failing three times in 2021 before a successful test flight in May 2022, as recalled by Air&Space Forces Magazine.

The funding for research and development (R&D) was also impacted due to the previously failed tests and delays. In its fiscal 2022 enacted budget, the ARRW team received $308.08 million, while a reduced $114.98 million spending was granted for fiscal 2023. For its fiscal 2024, the Air Force mentioned that it would continue allocating for the R&D of the ARRW, alongside the HACM, from its requested $11 billion budget—setting aside $150 million and $184 million, respectively.

The first operationally-configured test flight on December 9, 2022, was reported to be “very successful” by Kendall himself, adding that it “was a big step forward” for the hypersonic program. Before this, though, the secretary had already expressed dissatisfaction with ARRW’s slow progress.

In January, the Director of Operational Test and Evaluation (DOT&E) criticized the Air Force for missing several standard testing processes and failing to produce a definite test plan. Included in its report:

  • Flying operational tests without an approved test plan;
  • Potentially vulnerable to cyber disruption;
  • At the risk of insufficient test range availability; and
  • Lacking in modeling and simulation capability to properly evaluate the weapon;
  • Behind in warhead testing

The DOT&E also noted that the program “does not have a DOT&E-approved Integrated Master Test Plan nor has the Office submitted an Operational Demonstration Plan.”

Issues appearing one after the other, the future of the hypersonic weapon program looks bleak, and its end might be inevitable after all.

Nonetheless, Kendall remarked that the looming end of the ARRW may enable the service to shift its focus to a much more promising hypersonic program, the HACM.

“We’re more committed to HACM at this point in time than we are to ARRW,” Kendall told lawmakers on March 28.

Shifting to Hypersonic Attack Cruise Missile

In September 2022, the Air Force awarded money to Raytheon Technologies to develop prototypes for HACM, a scramjet-powered hypersonic air-launched cruise missile designed to execute “tactical flexibility to employ fighters to hold high-value, time-sensitive targets at risk while maintaining bombers for other strategic targets.”

Despite measuring smaller than ARRW, the HACM can similarly reach a maximum speed of Mach 5 with an F-15 Eagle as its launch platform.

Basically, the ARRW is for bombers, while the HACM is for fighter jets.

The project is the successor of the Hypersonic Air-breathing Weapon Concept (HAWC) and the American-Australian military technology partnership Southern Cross Integrated Flight Research Experiment (SCIFIRE) hypersonic programs, which uses the scramjet engine made by Northrop Grumman.

Kendall said that the HACM has a clear five-year plan budget in place and has so far “been reasonably successful, and we see a definite role for the HACM concept.”

With the possible cancellation of the ARRW, the service plans to be “more committed” to the HACM program.