Australia's mining boom might be over, but some of our brightest engineers say we shouldn't be looking at the ground in search of another economic windfall -- we should be looking to the stars.
Earlier this month, two concurrent conferences in Sydney looked at the future of mining.
However, these engineering and geotechnical experts weren't concerned with plumbing the depths of the ocean or drilling in ice shelfs; they were talking about the potential to mine asteroids, the Earth's moon and even other planets.
Space mining or off-Earth mining, a concept more rooted in science fiction than science fact until recently, operates under the same strategy as the mining we are already familiar with; find a valuable resource, work out how to dig it up and use it. That is the same idea behind mining asteroids or other planets... or, at least, that's one part of it.
"Asteroids have been known to have platinum group metals and other rare metals. It is possible you might want to bring those resources back to Earth," said Andrew Dempster, Professor in Space Systems Engineering and Director of the Australian Centre for Space Engineering Research at UNSW.
He's also the co-organiser of the Off-Earth Mining Forum, which was held earlier this month in Sydney.
"Nickel, platinum, gold and diamond. We think they will be available but we don't know," agreed Associate Professor Serkan Saydam, a geotechnical engineering expert at the UNSW School of Mining Engineering, another forum organiser.
Off-Earth mining targets are thought to be rich in precious metals, but it is not these shiny things academics are most excited about.
Instead, they are looking forward to mining plain rock and gathering common elements like hydrogen, helium and silicon. Why?
"We’re in a project with NASA which is about mining or processing soil on Mars to extract water, to make water for a colony," Dempster told The Huffington Post Australia.
"But water can also be split by electrolysis into hydrogen and oxygen, which is quite a useful rocket fuel."
"We could go to the moon, mine it for water, get rocket fuel, then use that fuel to get to Mars. The best way to get to Mars is to use the moon as a stepping stone."
"We don't yet have satellites which are refuellable, but the idea is quite an attractive one. Imagine a big communications station, like the NBN satellites. If they can be given months of extra fuel, you can put a large monetary value on that."
Space mining is most importantly about exploration and discovery, fuelled by simple economics and physics. Dempster said to launch something into space costs approximately $20,000 per kilogram.
His rationale: "if you can produce something in space for less than $20,000 a kilo, you’d do it." Silicon could be used to produce solar panels; moon rocks could be ground up and used as material for a 3D printer.
"The basic economics make it expensive to do things in space. There’s a strong economic imperative there, not to bring everything with you and to make things there," he said.
"The general suggestion is you're better using the resources you find in space, in space rather than bring them back to Earth.
"Traditionally, you dig something up and find one thing and throw everything else away. With asteroid mining, you might want to extract lots of different things from the rock, or not use anything. You could dig up rock, grind it up fine and use it for 3D printing."
The twin conferences in Sydney, Dempster said, were meant to bring together engineers, geologists, the space industry and the mining industry to pool talents. While space mining itself is still some years away -- he says the missions are still about 15 years away -- the field is expanding.
Dempster several companies have already sprung up to explore the economic viability of such missions, and hopes the field will continue to grow.
"The ambition is to get the mining and space communities to talk to each other. It is an awareness-raising thing. It is real, it's not science fiction or just nutters," he laughed.
"We’re developing business cases, there is a lot of real stuff going on. It is preliminary, but not fantasy."