An Australian-designed rocket propulsion system is heading to the International Space Station (ISS) for a year-long experiment that ultimately could revolutionise space travel.

Key points: The ion thruster could replace the current chemical-based rocket propulsion technology

The ion thruster could replace the current chemical-based rocket propulsion technology Can be powered using space junk, making it very fuel efficient

Can be powered using space junk, making it very fuel efficient Hope to test the tech for a year in space when it is taken to the International Space Station

The technology could be used to power a return trip to Mars without refuelling, and use recycled space junk for the fuel.

Former University of Sydney student, Dr Paddy Neumann — now of Neumann Space — and two co-inventor professors from his alma mater have developed an ion thruster that could replace the current chemical-based rocket propulsion technology, which requires huge volumes of fuel to be loaded onto a spacecraft.

Professor Marcela Bilek, one of the co-inventors, said they built a system in the early 2000s that was a "cathodic arc pulsed with a centre trigger and high ionisation flux".

At that stage of the project, it was basically a machine the size of a fist that spat ions from a very hot plasma ball through a magnetic nozzle at a very high velocity.

Professor Bilek explained a cathodic arc was a system that used solid fuels — metals — and worked similar to a welding arc.

"Where you're ablating the material from the solid and turning it into what's called a plasma — the sort of stuff you see in the sun," she said.

"And it's ionised, and that enables it to have high energy."

Measuring the pulse arc discharge

She said that prior to Dr Neumann joining them, the technology was used for thin films, and Dr Neumann had wanted to see whether they could use the technology to turn it into thrusters.

"Just because it spits out these particles at very high velocities," Professor Bilek said.

Dr Patrick Neumann has invented rocket thruster technology which could allow travel to Mars and back without refuelling. ( ABC News: Will Ockenden )

Dr Neumann said he first became interested in the technology when he was a third-year physics and engineering student at the University of Sydney.

He became interested in a special research project that the plasma physics department was doing, measuring the intensity of electric and magnetic fields during the pulse arc discharge.

"I helped them build the probe that took these measurements," Dr Neumann said.

"These measurements that I took suggested that the titanium ions, and the titanium plasma we made, were moving at about 23,000 kilometres per second, in the middle of a strong magnetic fields, so they would have had to slow down to get there.

"The particles that come out of the back end of a hydrogen oxygen rocket, such as what was used to power the space shuttle, they move at about 4.5 kilometres per second.

"So this made me think that you could use the pulse arc as a really efficient rocket thruster."

Space junk transformed into fuel for ships

The technology also uses recycled space junk, making it an environmentally aware project.

Professor Bilek said magnesium came out on top in their tests as the fuel with the highest specific impulse, and so the most fuel efficient.

"Magnesium happens to be a light metal, which is very abundant in aerospace materials," she said.

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"So all of that space junk that people have been talking about that's causing us a problem now with satellites in Earth orbit, is up there and available for recycling."

Professor Bilek said the next step for the Australian inventors was getting their technology to the International Space Station — possibly by the end of 2018.

"We've been testing on Earth in a vacuum system to simulate space, but it's a small vacuum system, so this will be the first real test of a true space environment with on-board monitoring of the system."

It will be placed in a module outside the ISS, powered, as Dr Neumann describes, by an extension cord from the station.

"What we'll be doing with our system is running it for as long as we can, hopefully for the entire year on the space station to measure how much force its producing for how long," he said.

"Are there any particular failure modes? Does it change its behaviour over time? Do we have any issues with environmental hazards?

"So that we can tell potential customers and project partners that we have in fact tested our drive in space."