Australia’s own pioneer in space exploration, Professor Michael Smart from UQ’s School of Mechanical and Mining Engineering, is redefining space travel with reusable high-speed planes with air-breathing engines.
Professor Smart’s groundbreaking concept is ready for launch.
Image: Professor Michael Smart with the UQ Centre for Hypersonics T4 Shock Tunnel.
In the glory days of the 1960s space race, NASA was asked by President Kennedy to “send an astronaut to the moon, and return him safely to earth before the decade is out”. At the time, there were two possible ways to do this; the first and easiest was to use massive rockets that were thrown away after each launch; the second and more futuristic possibility was to use a hypersonic airplane that could be used many times over for at least part of the trip.
NASA chose 'throw-away' rockets, and in 2017, the method of going to space is little changed from the Apollo moon missions of the 1960s. Almost all space launches of satellites or astronauts use expendable rockets.
Innovative thinkers like Elon Musk with his company, SpaceX, are trying to change this paradigm in an attempt to make space launch less wasteful and more economical. The University of Queensland, with its world leading scramjet technology, is planning to do the same by developing the SPARTAN launch system for small satellites, which is 90 per cent reusable.
A scramjet is an air-breathing engine, like a jet, that works at hypersonic speed; that’s mach 5 or faster than five times the speed of sound.
It uses oxygen from the air to combust with fuel and generate thrust. It’s much more efficient than a rocket, which must carry all its oxygen on-board. This oxygen can weigh up to 60% of the mass of the entire vehicle. The fact that a scramjet is air breathing also means that a scramjet-powered vehicle looks like an airplane; a hypersonic airplane.
Scramjets have been around for many years, but the technology has one significant limitation: scramjets only work at hypersonic speed. You cannot take-off under scramjet power. Given this limitation, UQ has been developing scramjet engines that work from mach 5 to mach 10.
With the market for small satellites well established and growing and the rapid pace that technology is advancing, the requirements of satellite launch systems are changing.
Both reduced scale and increased responsiveness are now the drivers of access to space. Due to the rapid development of micro-scale, low-power electronics, satellites that were once many thousands of kilograms now weigh just hundreds of kilograms.
HOW DOES SPARTAN WORK?
The SPARTAN three-stage system takes off vertically under the power of two first-stage boosters. These booster 'modules' use standard rocket engines, and speed the scramjet-powered second-stage aircraft to its mach 5 take-over speed. Once the boosters have finished their job, however, some magic happens.
Instead of falling into the sea, the boosters transform into light aircraft.
First they undergo a controlled re-entry, slowing down to around 150 kilometres per hour. Then they deploy a wing and propeller motor. Once this has been accomplished, each booster then simply turns around and flies back to the launch site, ready to be re-fuelled and flown again.
While this is occurring, the real job of satellite launch continues, with the SPARTAN hypersonic aircraft accelerating to mach 10 – over 12,000 kilometres per hour – under scramjet power.
The skin of the SPARTAN becomes red hot – up to 2000 degrees celsius. Modern high-temperature composites must be used for the outer shell and the scramjet to accomplish this.
During the four-minute acceleration, the small third-stage rocket and satellite is protected from the hypersonic environment, nested on the scramjet’s back. At mach 10 the scramjet has done its job, and the third-stage rocket blasts away, taking the 100-kilogram satellite up to its required orbit.
The scramjet-powered vehicle then turns for home, cruising back to the launch site and then gliding in to land. The third stage rocket is the only part of the system that does not return to be used again.
The commercial success of the SPARTAN small satellite launch capability would deliver rewards that Australia has yet to enjoy in the international high-tech space sector, including recognition as a genuine player in the field and offering our bright young engineers the jobs they deserve.
The University’s world-class researchers in advanced engineering, mathematics, neuroscience, chemistry, physics, psychology and human movements will cement their partnership with aerospace giant Boeing in 2017.
A purpose-built research and development facility has been constructed in UQ’s Hawken Engineering Building, at the heart of the University’s engineering hub, that will be home for around 30 Boeing engineers.
The Boeing Research & Technology Australia (BR&T–A) Brisbane Technology Centre will be conveniently located near other specialist research groups of interest to the aviation industry, including the UQ Centre for Hypersonics, renowned for its innovation in hypersonic aerodynamics research; the Queensland Brain Institute, where bird flight-patterns are being analysed for possible unmanned aircraft system application; and the Australian Institute of Bioengineering and Nanotechnology, home to several sustainable fuels project teams and polymer researchers.
Collaboration with the Boeing team means that academic research will be effectively translated to industry – a great boon for its relevance when applying for funding – and UQ students will also continue to benefit from the PhD scholarships and undergraduate internships Boeing offers.
Boeing‘s presence at UQ will be a showcase for Science, Technology, Engineering and Mathematics (STEM) projects, involving not just Boeing researchers, but UQ students and staff too. Topics already being investigated include a study of human factors in the flight deck and simulator technologies for future training approaches with Professor Stephan Riek, and Professor Paul Meehan’s work on incremental sheet forming, which, as an advanced manufacturing technology, has demonstrated high potential to shape complex three-dimensional parts without using specific high-cost tooling.
As a fully functioning industry workspace, the new BR&T–A Brisbane Technology Centre will demonstrate the realities of aerospace research and will provide opportunities for UQ staff and students to experience it first-hand.
Read the UQ News story here.