High speed threats and opportunities

Accompanying the Australian Government’s September announcement about acquiring nuclear submarines were a number of mostly unnoticed statements about investing in new capabilities, among them and perhaps least-noticed was a couple of brief lines on hypersonics.

“We are collaborating with the United States to develop hypersonic missiles for our air capabilities,” says the Investing in a Capability Edge briefing sheet.

In fact, Australia has been collaborating with the US on hypersonics research for around 20 years. While that wasn’t specifically directed at missile development, much of the technology is applicable to both civil and military capabilities.

There are a few relevant features of hypersonics. “Hypersonic weapons go really fast,” observed former US Air Force officer Robert Gass who is now with Boeing. In practice that means beyond Mach 5 – five times the speed of sound – with ambitions to push that well beyond Mach 10. But the capabilities to go consistently that fast may not yet exist – Russia’s 3M22 Zircon manages around Mach 6, according to a report on military.com, although other reports suggest Mach 9.  

At those sorts of speeds, there are interesting effects. Airframe design and materials are critical. Airflow at those speeds creates an ionised cloud around the missile, making it all-but invisible to radar systems. This isn’t wholly uncharted territory – at re-entry, a spacecraft is going around Mach 25, and technology to survive such speeds is well understood.

To be effective, a hypersonic missile must manoeuvre. But, at those sort of speeds, it won’t be flitting around the sky like a Sopwith Camel. In the terminal phase, a variation in heading of a degree or two may be all that’s possible…or needed. 

That manoeuvrability can make them most effective against fixed ground targets or large moving targets such as aircraft carriers. China’s DF-21 is designed to do precisely that, although it’s better described as a ballistic missile with a manoeuvrable re-entry vehicle. Indeed, one way to do hypersonics is to launch into space and use gravity to attain great speed on return to Earth. 

The other way, which is currently of greatest interest to military forces, is by use of boosted air-breathing hypersonic missiles, launched from aircraft, ships, ground vehicles, or fixed installations.

Though the US has invested extensively in hypersonics research with help from Australia, there’s a view that China and Russia are currently leading the way, simply because they’ve been at it longer and because the US has directed its development priorities at other technologies.

In October (2020) – on Vladimir Putin’s birthday – Russia announced that it had launched a Zircon hypersonic cruise missile from a ship in the Arctic White Sea. The missile reportedly flew 1,000 kilometres and struck a target in the Barents Sea.

“If we can take that claim at face value – we don’t know what Western intelligence knows about the missile system or the test – that’s a significant achievement,” wrote Australian Strategic Policy Institute (ASPI) analyst Dr Andrew Davies in March 2021.

Distinct from Zircon which is an air-breather, Russia’s Avangard is a hypersonic glide vehicle, lofted aboard a ballistic missile and reportedly capable of carrying conventional or nuclear warheads.   

China’s DF-ZF is another hypersonic glide vehicle, and was reported as being operational in 2019. This too is launched on a ballistic missile, and is reportedly capable of striking targets at a range up to 3,000 kilometres.

Would these and other systems work as claimed? We simply don’t know, and it could take an actual conflict to find out. But what is known and indeed, appreciated by everyone, is that existing missile defence systems may not work effectively against threats at hypersonic speeds. That’s especially so for missiles arriving at low level from over the horizon – a defence system may have just seconds to react.      

Meanwhile the US, with some help from Australia, is intent on developing comparable systems.

“Delivering hypersonic weapons remains a top priority, and the department remains confident that it is on track to field offensive hypersonic capabilities beginning in the early 2020s,” Pentagon spokesman Lt. Cmdr. Timothy Gorman said in a recent media statement.

The US has big ambitions. The Prompt Global Strike program dates back to the George W Bush administration, and aspires to be able to strike a target anywhere on Earth with a conventional warhead within an hour.

That would be by way of submarine or land-launched ICBM, air or submarine-launched hypersonic cruise missile, or even an orbital kinetic bombardment system (OBS).

The US is also working on air-breathing hypersonic cruise missiles. One issue with conventionally-armed ICBMs is that an adversary detecting an ICBM heading its way could reasonably assume this was a nuclear strike,
and react accordingly.

The US has run various hypersonics programs – Flightglobal says eight – in the usual confusing manner, developing a number of technology demonstrators, although much remains classified.

A few we know of include the US Defense Advanced Research Projects Agency (DARPA) Falcon Project which has produced various systems, among them the still classified X-41 Common Aero Vehicle, reportedly able to exceed Mach 7. Meanwhile, Boeing’s experimental X-51 Waverider has reportedly exceeded Mach 5 in test flights.

We know work is continuing because, in March 2021, the Pentagon acknowledged the failure of a rocket launching from the Pacific Spaceport Complex in Kodiak, Alaska. The problem was a booster unrelated to the test payload, the Common Hypersonic Glide Body (C-HGB). 

This is a joint US Army and Navy program, and comprises a rocket booster made by Lockheed Martin which carries the unpowered Dynetics C-HGB to altitude, from where it achieves speeds of up to Mach 17. The claimed range is 2,700 kilometres, but most everything else to do with this program is classified.

This does appear close to reality, as the US Army plans to field a truck-launched C-HGB in 2023, while the US Navy plans to launch it from submarines and Zumwalt class destroyers. Former US President Donald Trump colourfully referred to this as a “super-duper missile”.

Quite where Australia fits into the US programs isn’t all that clear, although we do have much to offer courtesy of long-running research programs dating back to the 1960s.

The University of Queensland HyShot program (1998-2006) flight-tested scramjet engines at speeds up to Mach 9.5. HyShot led to the joint Australia-US HiFIRE (Hypersonic International Flight Research Experimentation) program which, in 2017 successfully flight-tested a hypersonic glide vehicle designed for speeds of Mach 6-8.

In December 2020, Australia and the US signed an agreement on collaboration on development and testing of hypersonic cruise missile prototypes. That agreement is the latest in the Southern Cross Integrated Flight Research Experiment (SCIFiRE), a 15-year joint research program into scramjets, rocket motors, sensors, and advanced materials.

The objective of SCIFiRE is to develop an air-launched scramjet-powered precision-strike missile able to exceed Mach 5. Then Defence Minister Linda Reynolds said the experiment will culminate in flight tests to demonstrate how the weapon performs in operational conditions to inform any future acquisitions.

In March 2021, BAE Systems Australia announced it was increasing its investment to support rapid development of a sovereign high-speed weapons capability. The company calls this Project Javelin which it says builds on three decades of research into design and development of autonomous systems, weapons such as ESSM and ASRAAM missiles and the Nulka missile decoy, as well as hypersonic systems.

BAE is also developing technologies to support defence against hypersonic weapons. “That Australia has a solid foundation of research built over decades means that the rapid integration of newly developed weapons into the force structure is achievable,” BAE Systems Australia Chief Executive Officer Gabby Costigan said in a company release.

The future is approaching fast!

This article appeared in the Sep-Dec 2021 issue of ADBR.