A Speed Unmatched by Other Materials: Hypersonic Flight Takes Off in Australia

Hypersonic flight has well and truly taken off. But what exactly makes hypersonic technology so special?

When an airborne vehicle travels at hypersonic speed, it is moving at more than five times the speed of sound, otherwise known as Mach 5. For context, a trans-atlantic plane typically flies below Mach 1, while an F35 Joint Strike Fighter flies at Mach 1.6.

As such, hypersonic technology could be the key to the future of international air travel, where flights from Sydney to London could be undertaken in under three hours.

Australian researchers are at the forefront of this technology.

Practitioners from the University of Queensland have already developed new materials for use through the Hypersonic International Flight Research Experimentation (HiFiRE) program.

The initiative—one of the largest collaborative research programs between Australia and the United States—developed the 5B experimental rocket. The rocket has hit targeted speeds of Mach 7.5 (9,200kmph) and reached a height of 278km from Earth.

Professor Michael Smart said the flight placed the Australian aerospace industry on the international stage. "We’re excited by the contributions this and future HIFiRE flights will make to the advancement of hypersonic flight technology.”

HiFiRE 5B is one of 10 experimental flights as part of the international collaboration, which investigates the physical phenomenon of flying faster than five times the speed of sound.

The partnership places the US Air Force Research Laboratory, Boeing and HiFiRE in the same room, alongside world- class Australian researchers, to deliver sustainable solutions.

“The knowledge gained from these experiments will be applied to develop future flight vehicles and testing of advanced air-breathing hypersonic propulsion engines, known as scramjets,” Professor Smart said.

What is Hypersonic Technology?

Australia punches above its weight when it comes to developing hypersonic technology.

In the 1960s, Ray Stalker increased the maximum velocity limits on the ground-based testing of hypersonic flow by developing the free-pistondriven hypersonic shock tunnel at the Australian National University in Canberra.

Mr Stalker and his colleagues made significant inroads in their understanding of hypersonic flows with real gas (finite-rate chemistry) effects. These results have proven to be critical to the design and operation of re-entry vehicles such as NASA’s Space Shuttle.

At the same time, Australia was pioneering free-piston hypersonic shock tunnels, and used the research from those tunnels to power the next generation of flight.

By the 1980s, the scramjet engine was introduced as a combustion of fuel in a stream of air, which offered a highly efficient forward motion. The first demonstration of an in-flight pure supersonic combustion scramjet flight was tested at Woomera in 2002.

These achievements are the benefits of government-funded research, which is then suited to the needs of end-users in the global hypersonic market.

However, like all research endeavours, materials are the key to unlocking a hypersonic future.

New materials are constantly needed to deal with a range of environmental conditions and threats. From the coatings that repel water on a cargo ship, to the post-heat treatment on commercial jetliners; the benefits of materials science is far and wide.

As such, researchers work with end-users to develop, validate, and test a variety of structural designs, components and materials that are able to withstand the extremities of hypersonic flight.

Why is Hypersonic Technology Important?

In an ever-changing security and defence landscape, hypersonic technology is the key to skimming the stratosphere to hunt down long-range missiles and targets.

As such, the Federal Government is pouring additional funding into developing hypersonic technology to protect Australia’s national interest. In 2022, a $14 million purpose-built hypersonic research and collaboration facility was unveiled in Brisbane. The Eagle Farm establishment is tipped to supercharge Australia’s defence research. The purpose-built facility seeks to advance the nation’s understanding and use of hypersonic technology through flight test vehicles.

Defence Chief Scientist Professor Tanya Monro said the new precinct would demonstrate that Australia has the maturity to be able to contribute and create real deterrence.

“The technology developed here says the government will give Australia the ability to strike back should anything similar ever be used against us.”

“We have great confidence in our ability to make vehicles that really do withstand those intense and extreme conditions,” Monro said.

More than 60 staff will work at the facility, which will support collaboration between Defence, industry, universities and international partners to advance the development of hypersonic technology.

The research and development efforts will focus on high-speed and hypersonic flight research, and technologies. Researchers from the Department of Defence will work together to develop and characterise sovereign hypersonic technologies. They will also generate ‘true’ hypersonic flight conditions at a large scale in a classified laboratory. This builds on the HIFiRE project, which was formed to investigate hypersonic flight technology, the fundamental science and technology required, and its potential for next generation development.

It has received funding from the

Queensland Government National and International Research Alliances Program.

A Sea of Opportunities for Likeminded Allies

In September 2021, Australia, the United Kingdom, and United States announced a defence and security pact, which became known as the AUKUS alliance.

It supports trilateral ties across the Indo-Pacific region in an increasingly challenging geopolitical environment. The deal was centred around a fresh class of nuclear-propelled submarines, which would be stationed in Australia.

After the deal was announced, the AUKUS leaders expanded the agreement to include hypersonic technology in Australia.

Prime Minister Anthony Albanese said the AUKUS alliance is crucial for maintaining an international order, which includes a peaceful resolution of disputes free from coercion.

Hypersonics in Australia

“We have also made significant strides in our trilateral cooperation on advanced capability initiatives: hypersonics and counter-hypersonics, electronic warfare capabilities, cyber, artificial intelligence and autonomy, quantum technologies, and additional undersea capabilities,” he said.

At the time, Minister for Defence Peter Dutton said industry, universities and international partners will collaborate to advance Australia’s understanding and use of hypersonic technology through flight test vehicles.

“It’s a complex technological challenge to build vehicles capable of flying at five times the speed of sound, that skim the stratosphere, to target any location on the planet.”

“The technology that is developed here will help us to better defend against the malign use of this technology and give us the ability to strike any potential adversaries from a distance and deter aggression against Australia’s national interests,” he said.

The Federal Government has also announced a $3.5 billion fund to bolster Australia’s missile program. It includes plans to upgrade Australian missile manufacturing through the Eagle Farm facility in Brisbane.

Dr Malcolm Davis is a Senior analyst at the Australian Strategic Policy Institute, who said the challenge will be to deploy the capability at a high technological readiness level.

“We spend a lot of time doing science in the lab but then we don’t turn that science into actual capability whereas the Russians and Chinese seem to move more swiftly to deploy hypersonic weapons.”

Australia has had a long history of working with the United States on various defence projects. For instance, the two nations signed a collaborative agreement to develop and test hypersonic cruise missile prototypes under the Southern Cross Integrated Flight Research Experiment.

This program is based on more than 15 years of collaboration between Australia and the United States on science and technology research into hypersonic scramjets, rocket motors, sensors, and advanced manufacturing materials.

The new weapon will be a Mach 5-class precision strike missile that is propulsion-launched and powered by an air-breathing scramjet engine, which will be capable of being carried by tactical fighter aircraft such as the F/A-18F Super Hornet, EA-18G Growler and F-35A Lightning II.

Similarly, the HIFiRE program achieved some significant milestones, such as the design, assembly and pre-flight testing of the hypersonic vehicles and the design of complex avionics and flight systems.

This made it one of the most advanced hypersonic programs in the world.

But there is still more work to do. In fact, Australia is working with the United States and other partners on blending hypersonic technology into space.

The Brisbane-based aerospace engineering start-up, Hypersonix Launch Systems recently announced it was looking to launch a zero CO2 emissions hypersonic spaceplane capable of deploying small satellites into low Earth orbit.

The start-up signed a Master Research Agreement with the University of Sydney to research and manufacture the components of the zero emissions spaceplane.

Hypersonix hopes to build and operate a small satellite launch system in Australia for international customers.

“This is really important; if Australia can develop that sort of capability then that would be world-leading,” Mr Davis at the Australian Strategic Policy Institute said.

“The potential use of this hypersonics research park shouldn’t just be for defence applications in terms of missiles, it should also be applied to space access because that’s an area where we could potentially leap-frog ahead of other countries.”

There are over 100 small launch vehicle companies in development around the world. However, unlike Hypersonix, few use green hydrogen as a fuel, and none use scramjet technology for small satellite launches.

Hypersonix is seeking to create the world’s leading sustainable hypersonic technology, which disrupts the way humans fly to space and around the world.

This will reduce the technological risks and time to market, which secures a lower cost structure for end-users.