HCSW Becomes First Casualty Of DOD Hypersonic Push

Artist's concept of HCSW
Credit: Sandia National Laboratories

SINGAPORE—A Lockheed Martin program has become the first casualty in the U.S. Defense Department’s race to deploy a diverse portfolio of hypersonic missiles as soon as possible. 

The Hypersonic Conventional Strike Weapon (HCSW) program will be concluded after the delayed completion of a critical design review in spring 2020. The milestone event was originally scheduled for the third quarter of 2019. 

As the DOD rolled out the fiscal 2021 budget request, the U.S. Air Force issued a termination for convenience notice to Lockheed’s Space division on Feb. 10. 

Designed to be launched from a B-52, the Aerojet Rocketdyne-boosted HCSW was the first of five hypersonic missile prototype projects that have entered development since 2018. It features a “front end” derived from the Common Hypersonic Glide Body, which is the basis for boost-glide vehicles in development for the Army’s Long Range Hypersonic Weapon and the Navy’s Intermediate Range Conventional Prompt Strike programs. 

The Army and Navy proposed to accelerate development for the land- and sea-launched versions of the common glide body, a comparatively low lift-over-drag, axisymmetric shape that itself traces its origins to the successful Sandia Winged Energetic Re-entry Vehicle Experiment. 

Despite the cancelation, the Air Force praised the HCSW program staff for maturing technologies that can be leveraged in the Army, Navy and Missile Defense Agency programs. 

As HCSW winds down, the Air Force plans to focus initially on continuing development of the Lockheed Martin AGM-183A Air-launched Rapid Response Weapon (ARRW) prototype. The ARRW, featuring a high lift-over-drag wedge shape, is “on track” to achieve an early operational capability program in fiscal 2022. A first flight of the DARPA Tactical Boost Glide vehicle, which serves as a risk-reduction program for ARRW, is scheduled for later this year. 

Since it was developed from the 1970s-era, successful Swerve design, HCSW represented a relatively low-risk path to fielding a hypersonic weapon as quickly as possible. But its cancellation means the Air Force is relying on the more advanced ARRW design, which is deemed less mature. Two previous flight test attempts to demonstrate a similar hypersonic design failed, leading to the cancellation of the DARPA Falcon program in 2012.

At the same time, the Air Force’s interest is growing in another kind of hypersonic weapon technology. DARPA’s High-speed Air-breathing Weapon Concept (HAWC), a scramjet (supersonic combustion)-powered cruise missile, has matured faster than initially expected. DOD and Air Force officials are now discussing plans for launching an operational prototype for HAWC, with the goal of loading 15-20 of the relatively compact weapons into a single B-52. 

The DOD remains committed to fielding an air-launched hypersonic weapon in fiscal 2022 and the Army’s first ground-launched system a year later. The Navy plans to deploy the IRCPS prototype on a Virginia-class submarine in fiscal 2028. 

But the weapon is only one of the technologies required to field a successful capability, said Gen. Charles Brown, commander of Pacific Air Forces. Speaking on the sidelines of the Singapore Airshow here Feb. 10, Brown emphasized the need to field enabling technologies, such as more advanced command--and-control and intelligence, surveillance and reconnaissance systems. 

“In the time of flight 8 to 10 minutes that I’ve got a pretty good intel that the target is still going to be there, particularly if it’s a mobile target,” Brown said. “Those are things I’m thinking about. It’s nice to have this weapon, but I’ve got to have the whole thing.”

Steve Trimble

Steve covers military aviation, missiles and space for the Aviation Week Network, based in Washington DC.