The first commercial hypersonic vehicle satellite launch may be as little as seven years away, thanks to the creation of an Australian university spin-off company to build a reusable launch vehicle.
The University of Queensland, engineering consultancy BMT-WBM and UAV company Australian Droid & Robot have created Hypersonix, a company aimed at commercialising the SPARTAN (Scramjet Powered Accelerator for Reusable Technology AdvaNcement) system developed across more than 30 years of scramjet research.
SPARTAN is a planned three-stage satellite launch system. Its first stage will comprise one or two reusable “fly back” boosters which will separate and descend after their fuel is expended, deploying wings and a propeller to land for refurbishment and reuse. The second stage will be the SPARTAN scramjet system, which will fire after the first stage rockets have boosted it to Mach 5. Accelerating to around Mach 10, the air-breathing SPARTAN unit will remain inside earth’s atmosphere, gliding back to earth for reuse after launching a smaller third-stage rocket to take the payload on its final leg in to space.
University of Queensland Centre for Hypersonics Professor Michael Smart said that with around 90 per cent of the system reused, SPARTAN could halve the cost of a single launch of 150 kilogram payloads such as nanosats to sun synchronous orbit, compared with competing “throw away” rocket technology.
“The cost of that upper stage is actually quite critical to the cost of the whole system,” Smart told ADM. “That’s the part we will throw away every time, but it’s one tenth of the size of the whole system. We’re not throwing away 99 per cent of the mass.”
The heart of the system is a scramjet (supersonic combustion ramjet), which compresses supersonic airflow before adding fuel and igniting the mixture to produce thrust. The lack of turbines or mechanical compressors means the vehicle must be accelerated to supersonic speed for ignition, but can then operate efficiently at the speeds required to put SPARTAN’s small third-stage liquid-fuelled rocket within reach of space.
Smart believes the reusable first stage boosters and winged, steerable, hypersonic second stage give SPARTAN many of the benefits of a powered aircraft.
“This is not a ‘point and shoot’ where you’re going to dump most of the thing in the ocean and once you press the button it’s going to go wherever it’s going to go,” he said. “If there are problems with the scramjet it can turn around and fly back. Then it just lands as a glider.”
Although the science is “95 per cent of the way along”, Smart believes the next challenge is to harness new composite materials that can provide reliable, reusable service after experiencing temperatures of up to 1,600 degrees Celsius.
“There’s no new equation that we need to solve. It’s about putting different technologies together in a practical way that is commercial and where we can launch something much cheaper than our competitors will be able to launch. And a commercial company is the way to move it along.”