The US Air Force conducted a successful test in 2022 of a stealth cruise missile capable of carrying a nuclear warhead, government documents have revealed.
The secretive missile is classified as a Long-Range Standoff (LRSO) missile and is designed to replace the aging AGM-86 which was first used in the 1980s. Designed and produced by Raytheon, the US Air Force conducted eight successful tests of the missile as it carried a mock version of a new nuclear warhead named W80-4.
Details about the missile are sparse but the Air Force describes it as a stealthy and long-range upgrade to the AGM-86. The W80-4 is an upgrade to the W80 nuclear warhead, which is being retrofitted to make it compatible with the new missile.
The program is part of the Pentagon’s $1.2 trillion nuclear modernization program. The Pentagon’s nuclear facilities are infamously out of date, having just ended its use of floppy disks in 2019.
The missile was fired from a B-52 bomber, which itself is an ancient plane, first coming into use in the 1950s. However, the B-52 has proven to be a reliable workhorse for the US military and has received some upgrades over the decades.
The US Air Force tested the missile’s ability to safely separate from the B-52, the deployment of the missile’s slight surfaces, engine operations and flight control actuations, as well as its controlled flight after deploying from the B-52.
“The missile successfully released from the aircraft, powered its engine, and executed all in-flight maneuvers. A Lawrence Livermore National Laboratory (LLNL) and Sandia National Laboratories (SNL) team developed the warhead test asset, an Environmental Test Unit. The Environmental Test Unit successfully executed all pre- arm/pre-release criteria and collected environmental data for the duration of the flight. This is a significant milestone for the joint program and first collection of representative LRSO free flight data, used to populate the W80-4 STS, define environmental specifications, inform design decisions, and validate computational models,” the report said.
One issue that was found with the missile was that when four or more missiles were loaded in the B-52’s rotary launcher “the stores clash with the fuel tank.” The Air Force said at the time it expected the issue to be resolved by May 2023.
The US Air Force was originally tasked with making a version of the new LRSO missile that was capable of delivering a conventional warhead, "within five days" of completing the nuclear version, but Congress removed that requirement in the fiscal 2020 National Defense Authorization Act.
The decision on whether the missile should enter full scale production is expected in late 2027.