The US Army Revived a Canceled Supergun to Test Hypersonic Warheads

The US Army has fired a full-scale, live hypersonic warhead from a cannon at Yuma Proving Ground in Arizona, in a test disclosed by the range's official publication, The Outpost, on July 30, 2026 and picked up by the defense press on August 4. The gun used is the Heavy Artillery Test System, hardware derived from the canceled Strategic Long Range Cannon programme.

The Strategic Long Range Cannon was conceived as an ultra-long-range artillery piece able to strike targets more than 1,000 miles away. The Army abandoned it as a weapon. What survived is a very large gun capable of accelerating a payload to extreme velocity on a fixed range, and that turns out to be useful for a different problem.

Hypersonic weapons draw most of their destructive effect from kinetic energy rather than from explosive filler, which means the only way to know what a given warhead design does on impact is to bring it to velocity and hit something. Doing that with a rocket-propelled test vehicle costs a flight test each time. A gun does it repeatedly, on a schedule, at a fraction of the price, and with high-speed cameras and telemetry trained on the impact.

The effort was run jointly by Lawrence Livermore National Laboratory, the Department of Energy laboratory that handles much of the country's warhead physics work, and the Army Combat Capabilities Development Command Armaments Center. It began roughly two years ago and ran an inert proof-of-concept firing first, to validate the physics before committing to live ordnance. Design refinements followed, then the live shot.

The engineering problem was surviving the barrel. DEVCOM-AC developed an Integrated Launch Package able to withstand the acceleration inside the gun, which is far more violent than anything a warhead experiences on a missile, along with an electronic safe-and-arm fuze. On test day personnel withdrew to bunkers, a truck backed the launch package up to the weapon, the gun crew loaded the warhead and propelling charge, and the test director counted down. Review of the high-speed footage confirmed the shot as a complete success, according to the range's account.

The distinction worth keeping in view is that this is a test rig, not a weapon. Nothing about the demonstration puts a cannon-launched hypersonic round into service, and no unit will field the HATS. What it changes is the cost and cadence of lethality assessment for the programmes that will be fielded, at a moment when the American hypersonic portfolio, including the Army's own Dark Eagle long-range hypersonic weapon, is moving from development into deployment.

Hypersonic is conventionally defined as sustained flight above Mach 5, roughly 6,174 km/h, a threshold that only a small number of fielded systems cross; the fastest missiles in the world sit well beyond it. Warhead behavior at those speeds is poorly characterized by comparison with subsonic and supersonic weapons, which is precisely the gap the cannon is meant to fill.

Officials said the demonstration has already drawn interest from several other hypersonic programmes considering the approach for their own test campaigns. Neither the exact date of the firing nor the warhead design involved has been released.