RAAF Super Hornets to test US hypersonic weapons on Australian firing ranges

The Royal Australian Air Force's (RAAF) F/A-18F Super Hornets will be used as part of a test campaign for a US-designed hypersonic strike weapon starting later this year.

In a recent report on current US defense programs, the US Government Accountability Office (GAO) – the US equivalent of the Australian National Audit Office (ANAO) – highlighted the risks associated with the timing of a certain number of testing and development programs due to a lack of resources. within the US Department of Defense.

Among these programs was the US Air Force's Hypersonic Land Attack Missile (HACM), a two-stage missile capable of being air-launched, flying toward a target, and striking it at more than five times the speed of sound.

The United States has several major weapons testing ranges scattered along its coastline and in the southwestern states of Nevada and New Mexico, but none have the same space, remoteness and the absence of airspace restrictions like Woomera in South Australia or the Delamere and Bradshaw shooting ranges in the north. Territory.

And with the implementation of the AUKUS construct, particularly those elements of Pillar 2 which include the joint development and exploitation of hypersonic technologies, there are now fewer export and security restrictions imposed on the United States during the diffusion or sharing of these technologies with Australia.

The GAO report states that availability and test range limitations in the United States have been a problem for hypersonic programs.

“To alleviate this problem, the HACM program is integrated into the Southern Cross Integrated Flight Research Experiment. [SCIFiRE]a joint American-Australian effort,” he says.

“Through this joint effort, several of HACM’s planned flight tests will take place in Australia using Australian Air Force F/A-18s.”

SCIFiRE is a 15-year joint collaboration agreement between Australia and the United States to develop and test prototype hypersonic cruise missiles and conduct research into hypersonic scramjets, rocket engines, sensors and advanced manufacturing materials.

The Morrison government's Defense Strategic Update and Force Structure Plan (DSU/FSP) 2020 included funding of between $6 billion and $9 billion to carry out high-velocity, long-range strikes, including hypersonic research until 2040.

The RAAF operates 24 Boeing F/A-18F attack aircraft which have already been identified as launch aircraft for any future hypersonic weapons the RAAF may acquire, so it makes sense that they would be favored for the test campaign.

HACM is designed and built by Raytheon (RTX) and Northrop Grumman who were awarded a US$985 million (A$1.5 billion) contract in September 2022 to develop the system.

The missile consists of two stages: a rocket booster and an “air-breathing” jet cruise engine. Once it has been launched and accelerated to hypersonic speeds by the booster, it separates and the scramjet takes over for cruise and terminal flight to the target.

The US Air Force has previously said it will integrate the HACM into its Boeing F-15E Strike Eagle fleet, but it is likely it will be adapted for use on other aircraft as well. The RAAF has previously said its F/A-18F and F-35 fighters and perhaps the larger P-8A Poseidon maritime strike aircraft would be future hypersonic weapons delivery platforms.

The GAO says the U.S. Air Force plans to produce 13 missiles as part of a rapid prototyping effort that includes test missiles, spare parts and canisters for residual operational capability.

It states that development of the HACM rapid prototyping effort began in 2022 and was based on another US Defense Advanced Research Projects Agency (DARPA) scramjet demonstrator known as the Hypersonic Air-breathing Weapon Concept (HAWC) .

Designed to enter service in 2027, HACM is one of five U.S. hypersonic missile programs in development.

Others include the US Air Force's Lockheed Martin AGM-183A Air-Launched Rapid Response Weapon (ARRW), a larger, longer-range weapon designed to be launched from a bomber and which, after several failures, made its first successful test flight from a B-52H in May 2022.

The US Navy is developing the Conventional Prompt Strike (CPS) system, a hypersonic boost-glide missile program aimed at developing a system that can be launched from surface ships and submarines.

The US Navy also has its own requirements for Hypersonic Air-Launched Offensive (HALO) anti-ship missiles, designed to be launched by carrier-based aircraft, but which at first glance appear to align with good many of the same requirements as the HACM. . If integration with the RAAF's F/A-18F – an aircraft operated by the US Navy – is successful, the US Navy will likely become much more interested in HACM.

Not to be outdone, the US military is conducting its Long Range Hypersonic Weapons (LRHW) program which also aims to develop a boost-glide hypersonic weapon for fixed and mobile surface-launched applications.