Somewhere in the sprawling test ranges of the American Southwest, a missile designed to fly at five times the speed of sound is working its way toward the finish line. The Hypersonic Attack Cruise Missile, known as HACM, is the U.S. Air Force’s bet that it can strap a scramjet-powered weapon under the wing of an F-15 fighter and give frontline commanders the ability to punch through the most advanced air defenses on the planet. As of mid-2026, the program is funded, contracted, and moving toward a completion window that could put live rounds in the hands of operational squadrons within the next year.
A nearly $1 billion contract with a tight clock
The foundation of the HACM program is a single, sweeping contract. On September 22, 2022, the Department of Defense awarded Raytheon Missiles and Defense a task order worth $985,348,124. The scope is unusually broad for one contract vehicle: design, development, critical design review, qualification testing, aircraft integration, manufacturing, initial delivery, and flight testing. The expected completion date is March 2027, giving the team roughly four and a half years from contract signature to final deliverables.
Bundling all of those milestones into a single task order was a deliberate choice. Traditional Pentagon acquisition moves through those stages sequentially, often across multiple contracts spanning a decade or more. HACM’s structure compresses the timeline by running work streams in parallel. The trade-off is obvious: if a technical problem surfaces late, there is far less schedule cushion to absorb it.
Why a scramjet cruise missile changes the equation
HACM is not the Air Force’s first attempt at an air-launched hypersonic weapon, but it is a fundamentally different kind. The service’s earlier program, the AGM-183A Air-launched Rapid Response Weapon (ARRW), was a boost-glide design: a rocket would accelerate a warhead to hypersonic speed, and the warhead would then glide unpowered toward its target. ARRW suffered repeated test failures and was officially canceled in March 2023.
HACM takes a different approach. It is powered by a scramjet, a type of air-breathing engine that compresses incoming air at supersonic speeds to sustain combustion without the rotating machinery found in a conventional jet engine. Northrop Grumman developed the scramjet for the program. The advantage of a scramjet-powered cruise missile over a boost-glide weapon is sustained powered flight: rather than trading altitude for speed on a ballistic arc, HACM can maintain its velocity and maneuver throughout its flight path. That makes it harder to predict and harder to intercept.
Building a reliable scramjet is one of the hardest problems in aerospace engineering. The engine must operate in air heated to thousands of degrees by compression, maintain stable combustion across a range of altitudes and speeds, and do so with enough efficiency to deliver useful range. These challenges have bedeviled hypersonic programs worldwide for decades. Whether HACM’s scramjet has cleared those hurdles in testing is not confirmed in publicly available records, but the program’s continued funding and lack of reported cancellation or restructuring suggest it has not hit the kind of wall that killed ARRW.
Why the F-15 carries it
Designing HACM to launch from an F-15 is a pragmatic decision rooted in physics and logistics. The F-15E Strike Eagle and its newer F-15EX Eagle II variant have external hardpoints rated for heavy, oversized munitions. They also provide the electrical power and cooling capacity that an advanced weapon with onboard guidance and a scramjet ignition sequence demands. Critically, F-15s are already deployed at bases across the Pacific and the Middle East, regions where the ability to strike hardened or deeply defended targets at extreme speed would matter most in a conflict.
Choosing an in-service fighter also sidesteps the years-long delay that would come from waiting for a new platform. The F-15 fleet is expected to remain operational well into the 2030s, giving HACM a stable ride for its initial fielding and beyond. Whether additional aircraft, such as the B-52 bomber, might eventually carry the weapon has been discussed in defense circles but is not part of the current contract scope.
What the GAO’s assessment signals
The Government Accountability Office published its 2025 annual weapon systems assessment, designated GAO-25-107569, under the subtitle “DOD Leaders Should Ensure That Newer Programs Are Structured for Speed and Innovation.” The report evaluates whether the Pentagon’s newest acquisition programs follow leading practices for schedule realism, incremental development, and risk management.
The GAO does not single out HACM with program-specific grades or schedule metrics. But its central finding lands squarely on programs built the way HACM is built: compressed timelines demand realistic baselines and disciplined management, because history shows that aggressive schedules are the ones most likely to slip. Across decades of annual reviews, the GAO has documented a pattern in which defense programs set ambitious initial targets, encounter technical surprises, and then absorb cost and schedule growth that was foreseeable from the start.
Hypersonic weapons have been especially prone to these dynamics. Managing extreme heat at sustained Mach 5 flight, maintaining guidance accuracy during high-speed maneuvers, and qualifying a scramjet engine across its full operating envelope are problems that do not always reveal themselves until late-stage testing. The GAO’s systemic caution applies to HACM even without a dedicated audit of the program.
The strategic backdrop: why the rush matters
The urgency behind HACM is not abstract. China has tested and, by some assessments, fielded hypersonic weapons of its own, including the DF-ZF boost-glide vehicle. Russia has deployed the Zircon hypersonic cruise missile on naval platforms. Neither country’s weapons are direct analogs to HACM, but their existence has created intense pressure inside the Pentagon to close what senior officials have described as a capability gap.
An air-launched hypersonic cruise missile carried by a tactical fighter offers something neither a ship-launched nor a ground-launched system can: the ability to position the launch platform quickly, operate from dispersed airfields, and strike targets deep inside defended airspace without requiring a bomber-sized aircraft or a fixed launch site that an adversary can target first. For Air Force planners focused on a potential conflict in the Western Pacific, that combination of speed, range, and platform flexibility is the core of HACM’s value proposition.
What remains unconfirmed from public records
Despite the program’s momentum, significant gaps exist in the public record. No official flight-test results, technical readiness assessments, or updated schedule projections specific to HACM have been released since the 2022 contract award. The distinction matters because a funded contract and a proven weapon are not the same thing.
There is no public confirmation of how many missiles Raytheon has produced, whether the “initial delivery” referenced in the contract scope has occurred, or whether those deliveries involved test articles or production-representative rounds. Test articles prove a design works under controlled conditions. Production-representative rounds prove the manufacturing process can replicate that performance reliably and at scale. Both must succeed before a weapon is declared combat-ready.
Operational testing and training timelines are also absent from public documents. Hypersonic weapons introduce new planning factors for range safety, target coordination, and allied interoperability that take time to work through. No public schedule shows when operational squadrons might begin receiving missiles or conducting live-fire exercises.
Air Force officials have spoken about HACM’s progress at defense industry conferences, generally expressing confidence in the program’s trajectory. But conference remarks are not the same as formal milestone announcements, and they rarely include the technical detail needed to independently assess whether the weapon is ahead of, on, or behind its contracted schedule.
Where the program stands heading into 2027
The strongest defensible statement about HACM as of mid-2026 is this: the program has a funded development contract worth nearly $1 billion, a defined scope of work that covers every stage from design through manufacturing, and a completion date of March 2027 that reflects the Air Force’s original plan. The weapon uses a Northrop Grumman scramjet engine, is designed to launch from F-15 fighters already in the fleet, and fills a role that the canceled ARRW program left vacant.
Whether HACM reaches operational capability ahead of, on, or after that March 2027 contract endpoint will depend on factors that are not yet visible in the public record: flight-test outcomes, production-line readiness, and the Air Force’s willingness to accept the weapon into its operational inventory at a given level of maturity. The clearest signals will come from future flight-test announcements, contract modifications that extend the timeline or increase the value, and formal acquisition milestone decisions recorded in federal procurement databases.
For now, HACM represents the Air Force’s most advanced attempt to put a hypersonic strike weapon on a fighter jet. The engineering is hard, the schedule is tight, and the strategic stakes are high. The next twelve months will determine whether the bet pays off.
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*This article was researched with the help of AI, with human editors creating the final content.
