Next time you are with grandma, open her wardrobe and sniff deeply. It’s rocket fuel you can smell.
Naphthalene may be better known as ‘mothballs’, but the smelly and solid white matter is at the heart of a new rocket propulsion system designed and tested at the Australian National University (ANU).
ANU PhD researcher Dimitrios Tsifakis came up with the idea of using the naphthalene for the CubeSat project and describes it as the perfect alternative to hot and charged gas plasma.
“It’s cheap, non-corrosive and easily accessible – you can get milk balls in the supermarket,” he says.
Not only is it cheap and easy to buy, but when heated, the naphthalene is converted from a solid to a gas, eliminating the danger of the liquid splashing around in the rocket thruster.
“Everyone knows the old smell in Grandma’s wardrobe – now it’s the latest in space technology,” says Dimitrios.
ANU researchers have designed the innovative thruster, with its very familiar smell, in just six months from design to delivery. Primary testing was performed on campus in Acton.
Powered by the new technology, the aptly named Bogong satellite will be launched into space in mid-2022 among half a dozen other small satellites that the Australian space service company Skykraft will use for tracking and communication with aircraft, facilitated by the Canberra-based space company . Boswell Technologies.
Dimitrios says rocket scientists have turned to mothballs in the past, but thanks to these two Canberra companies, ANU are the first to produce a fully functioning thruster in their laboratory.
The Bogong thruster will heat the substance up to about 70 degrees Celsius, or when it turns to gas, before heating even more below its exit from the thruster nozzle.
Exposure to very large amounts of naphthalene can cause damage to blood cells in humans and animals, but Dimitrios says emissions from the thruster are not a cause for concern.
“The Naphthalene thruster will only be operated when the satellite is in space, so there is absolutely no risk of it causing any damage,” he says. “It can be considered a ‘green propellant’ as it is much less dangerous than other propellants used.”
Dimitrios says scientists have discovered naphthalene in space, so “it’s already up there”.
Project Manager Professor Rod Boswell, of Boswell Technologies, describes Bogong and its family of milk-powered satellites as the “first step in making global aviation safer in a cost-effective way”.
The team says the new thruster design can extend the life of the satellite by up to 20 percent – equivalent to an extra year of operation – because the simple design uses more fuel than a conventional plasma thruster, but houses very few complicated electronics. This means that its space can be used to house more naphthalene.
Professor Christine Charles, head of the ANU Space Plasma, Power and Propulsion Laboratory, led the rocket experiments by heating prototypes in a space-simulated vacuum chamber called ‘WOMBAT’.
“There are very few places in the world that can test space conditions, perform laboratory work and work closely with industry,” she says.
“We refined it every day with our pressure balance, and now Bogong is ready to launch. Firing mothballs into space could make the sky safer.”