When astronauts return to the moon in the next decade, they will do more with the dust than leave footprints in it.
A British firm has won a European Space Agency contract to develop the technology to turn moon dust and rocks into oxygen, leaving behind aluminium, iron and other metal powders for lunar construction workers to build with.
If the process can be made to work well enough, it will pave the way for extraction facilities on the moon that make oxygen and valuable materials on the surface, rather than having to haul them into space at enormous cost.
“Anything you take from Earth to the moon is an added weight that you don’t want to carry, so if you can make these materials in situ it saves you a lot of time, effort and money,” said Ian Mellor, the managing director of Metalysis, which is based in Sheffield.
Analyses of rocks brought back from the moon reveal that oxygen makes up about 45% of the material by weight. The remainder is largely iron, aluminium and silicon. In work published this year, scientists at Metalysis and the University of Glasgow found they could extract 96% of the oxygen from simulated lunar soil, leaving useful metal alloy powders behind.
Nasa and other space agencies are in advanced preparations to return to the moon, this time to establish a permanent lunar base, or “moon village” where nations will operate alongside private companies on critical technologies such as life support, habitat construction, energy generation and food and materials production.
The Esa contract will fund Metalysis for nine months to perfect an electrochemical process that releases oxygen from lunar dust and rocks by sending an electrical current through the material. The process is already used on Earth, but the oxygen is released as an unwanted byproduct of mineral extraction. To make it work for lunar explorers, the oxygen must be captured and stored.
Under the contract, the firm will try to boost the yield and purity of oxygen and metals from the rock while reducing the amount of energy the process consumes. If the technology looks promising, the next step will be to demonstrate oxygen extraction on the moon.
The oxygen released from the lunar surface can be combined with other gases to produce breathable air, but it is also a vital component of rocket propellant that could be manufactured on the moon and used to refuel spacecraft bound for deep space.
“If you want to go further out into space, it’s a gas station on the moon essentially, to get into deeper space,” said Mellor.
Mark Symes, who works on the process at the University of Glasgow, said moon rock represents “an enormous potential source of oxygen” to support human exploration of Earth’s satellite and the wider solar system.
“Oxygen is useful not only for astronauts to breathe, but also as an oxidiser in rocket propulsion systems,” he said. “There is no free oxygen on the moon, so astronauts would have to take all their own oxygen with them to the moon, for life support and to enable their return journey, and this adds considerably to the weight and hence expense of rocket launches bound for the moon.”
Sue Horne, the head of space exploration at the UK Space Agency, said: “In the future, if we want to travel extensively in space and set up bases on the moon and Mars, then we will need to make or find the things required to support life: food, water and breathable air.”
For more than four decades, human space exploration has been restricted to missions to the international space station, an orbiting outpost about 220 miles above the Earth. The focus over the coming years will be the construction of a new station in orbit around the moon that will act as a stopping-off point for humans to establish a presence on the lunar surface, and potentially as a base from which to launch outwards to Mars.
The Lunar Gateway programme has set itself the ambitious goal of returning humans to the moon as early as 2024, with crews transported aboard Nasa’s Orion spacecraft. The rocket is expected to make its first un-crewed flight next year.
Esa has provided power and propulsion units for the first Orion flight and has agreed contracts to build the main crew module for the lunar station.
