They say it’s about moonshots, but Jonathan Lun’s ambition is to do something considerably harder than land a man on the moon.
For the last decade, the rocket scientist has been working on South African satellite programs for the SA National Space Agency (SANSA) and Denel, and is one of just a handful of people globally working on a revolutionary propulsion system that could lead to humankind’s ability to mine asteroids in the future.
And his technical expertise and ambition just won over the judges at the Singularity University Global Impact Challenge for Southern Africa, and a place on the prestigious nine week SingU Global Solutions Program course in the US later this year.
Asteroid mining is a perennial topic that comes up in sci-fi stories and think-tank papers as a way of improving access to raw metals for Earth-bound industries. Some believe that as mines run dry on Earth, they could be the only source of some materials in the future. A single 300m long asteroid, Lun says, could yield enough iron to keep South Africa’s metalworkers going for a year. One 30m long asteroid is believed to hold $50bn of platinum.
One challenge that has to be overcome before asteroid mining is remotely feasible, however, is getting mined materials back to Earth – and in particular, fuelling rockets for the return journey. A rocket loaded up with enough fuel for both outward and inward legs of the journey would probably be too heavy to take off in the first place, or at least prohibitively expensive no matter what value of metals it returned.
And this is where Lun comes in. He’s published papers looking at the feasibility of a “vacuum arc thruster” for powering a mining craft. Vacuum arc thrusters create thrust via plasma jets by pulsing electricity between two electrodes (an anode an a cathode), and burn up the cathode as fuel.
Lun’s theory is that if a vacuum arc thruster can be built that’s big enough, a mining vessel could propel itself back to Earth by burning up some of the metal’s it’s extracted as that cathode.
And it’s very much a theory right now. While Lun has built tiny prototypes to show how existing models of vacuum arc thrusters can be improved, it’ll be many years before they’re ready for testing in even the smallest satellite, he says.
Still, nine weeks at Singularity University will put him in good company to explore applications of his idea. SingU was cofounded by Peter Diamandis who, as well as creating the X-Prize for the first private sub-orbital space flight, is also the co-founder of Planetary Resources, a company set up to investigate the commercialisation of asteroid mining.
Other finalists at the Singularity University Global Impact Challenge tonight included maker Spencer Horne, who wants to use airships to transport goods across Africa, and Mike Schmid, an engineer who is researching low-cost batteries based on saltwater and carbon nanofoam.
The most intriguing runner-up, though, was entrepreneur Benji Coetzee. Her firm, Empty Trips, is already operational in South Africa and aims to reduce the high cost of logistics on the continent by matching empty trucks, planes and trains – often on the return leg of a big delivery – with goods that need moving using an Uber-style matching algorithm.