Jamie Seidel
Jamie Seidel is a freelance journalist based in Adelaide.
A West Australian doctoral student is on a fast track to the Moon. Or, at least, his novel satellite thruster system is. All thanks to a hefty dose of boldness and serendipity.
“I submitted a cold resume application to the German Aerospace Center last year. I was there within two months,” says Curtin University PhD candidate Daniel Turner.
The 24-year-old was interested in their advanced spacecraft propulsion system. He returned in June after spending six months at a research facility deep in a German forest.
The upshot?
His miniature space thruster idea will be aboard a Curtin University’s Binar (Fireball) Prospector spacecraft destined to explore the Moon by the decade’s end.
Why?
Binar Prospector is a 12-unit cubesat. That’s roughly the size of two large cereal boxes.
And at that size, every millimetre of space and every gram of weight matters.
So when Turner proposed using a set of low-power, multimode electric manoeuvring thrusters designed to operate on the same gas-fuel system as the satellite’s primary engine, the Binar Prospector project’s managers were all ears.
Sounds obvious. Why hasn’t anyone thought of it before?
“I read about multimode thruster systems from a paper published in 2001, which I think was the first time it was proposed,” says Turner. “They never did anything about it.”
Read: Other Australian satellite thruster finds success
But the Binar project had a problem.
It needed a large engine to provide the thrust to change orbit. But it also needed much smaller thrusters to fine-tune its orientation and momentum to accurately target its sensors.
Usually, these systems are separate. Each with its own fuels, heaters and plumbing.
What clinched the idea was Binar’s main engine. It’s being designed and built by ISP Tech – a commercialised spinoff of the German Aerospace Center (DLR). And it uses ethane and nitrous oxide as its fuel.
“Nitrous oxide is the fuel I was going for,” says Turner. “And perhaps nobody’s done this before because nitrous oxide has mostly only flown in space in the past five years”.
Using the same fuel saves weight, space and complexity. But this fuel is also safe.
“The small craft propulsion industry is pivoting away from these incredibly toxic fuels like hydrazine. It’s carcinogenic, horrible stuff. But it’s also incredibly expensive because of all the safety procedures you have to build around it.
“It costs about half a million dollars to fuel up a small spacecraft with hydrazine. Whereas I can fill one up with nitrous oxide – laughing gas – in the lab myself for about $20.”
Not all thrusters are designed equal.
Some work best at large scales. Others small. Some are better for big boosts. Others tiny, accurate nudges. This helps bridge those gaps.
“By adding my thrusters, we’re not adding complexity,” Turner says. “We’re actually reducing it significantly. And my thrusters can act as a backup to the primary propulsion system”.
The need for such backups is a lesson NASA learned the hard way this year.
Several of its recent Artemis CubeSats failed because of problems with their propulsion systems.
“So we’re really trying to make a fault tolerant system that can do many different things,” says Turner.
“My thruster has done a bit of testing. It requires another six months or so. Alongside that is figuring out the nuts and bolts of integrating it with the ISP Tech motor and fuel tank – and making sure it all stays reliable.”
The first example is contracted to be delivered to Curtin University in 2025 for integration and testing with the Binar spacecraft architecture.