The U.S. Air Force (USAF) has detailed its new hypersonic missile development effort called Hypersonic Attack Cruise Missile (HACM) program.
In a recent interview with the Air Force Magazine, Program Executive Officer (PEO) for Weapons Brig. Gen. Heath A. Collins said that the Air Force is moving forward with the HACM program as one of its top two hypersonic weapons programs, with the other being the AGM-183A Air-launched Rapid Response Weapon (ARRW).
Speaking to Air Force Magazine in September, Collins said HACM and the ARRW are “really the two big tickets that we’re looking at from a warfighter focus.”
“We are the lead development office for the Air Force when it comes to hypersonic weapons,” Collins said. “The ARRW program is down here as well. We’re also in the midst of starting the new HACM hypersonic cruise missile.”
Aviation Week’s Steve Trimble first reported on the existence of two classified hypersonic programs, then only known by the acronyms HACM and HCCW, in July 2019.
According to the Air Force Mag report, HACM is the one described as “Future Hypersonics Program” on a sources sought notice released on federal contracting website earlier this year by the Air Force Life Cycle Management Center (AFLCMC) Armament Directorate under the Air Force Materiel Command (AFMC).
According to the notice, the effort involves “systems integration of a Weapon Open System Architecture (WOSA)-based, solid-rocket boosted, air-breathing, hypersonic conventional cruise missile, air-launched from existing fighter/bomber aircraft into a preliminary design.”
The HACM missile will likely be powered by a solid rocket motor (SRM) during launch and the propulsion will be taken over by an air-breathing engine which will enable hypersonic speeds during cruise phase of the flight. The sustained air-breathing hypersonic propulsion will be enabled by a ramjet, scramjet (supersonic combustion ramjet), or a dual-mode scramjet engine.
The HACM will be different from ARRW as the weapon will use air-breathing engine for propulsion. In contrast, ARRW is a is a boost-glide system that consists of a rocket booster and a hypersonic glider warhead. In the case of ARRW, the booster rocket accelerates to high speeds after being launched from an aircraft and then release the hypersonic glide warhead payload which then glides unpowered to its target at hypersonic speeds.
As it is powered by an air-breathing engine, the HACM missile will have to fly well within the atmosphere as it requires air for propulsion. The range is also expected to be less compared to the ARRW.
The notice said that the “Future Hypersonics Program” effort is expected to achieve the Preliminary Design Review (PDR) by the fourth quarter of FY2021.
In August, Air Force Research Laboratory (AFRL) released another RFI for a new hypersonic demonstrator under its Expendable Hypersonic Multi-Mission Air-Breathing Demonstrator (Mayhem) program. Through the Mayhem program, the AFRL is interested in the design, fabrication, integration, and necessary research needed to enable a larger-scale expendable air-breathing hypersonic multimission flight demonstrator.
The Mayhem System Demonstrator (MSD), which will be developed under the program, will be capable of carrying larger payloads over distances further than current hypersonic capabilities allow. The payload bay will be modular and capable of carrying/delivering at least three distinct payloads in order to execute multiple Government-defined mission sets.
The Air Force Mag report said that the USAF plans to hire Boeing, Lockheed Martin, and Raytheon to design a hypersonic cruise missile this fiscal year. The report added that both the “Future Hypersonics Program” and the Mayhem program would reach their PDRs around the end of fiscal 2021.