Aqualunar Challenge: Lunar microwave purifies ice to create drinking water for astronauts

A technology that uses microwaves to melt lunar ice has been developed to provide clean, drinkable water for astronauts.

The technique, which also uses ultrasound to break down contaminants, has won the UK Space Agency-funded Aqualunar Challenge, an international prize for technologies seeking to make human habitation on the lunar surface possible. Countries around the world are planning lunar missions and the UAE’s next goal in space is to place an Emirati astronaut on the surface of the Moon within 10 years.

About 5 per cent of the soil around the Moon’s south pole is estimated to be water frozen as ice. If it can be successfully extracted, separated from the soil and purified, it would make a crewed base viable.

SonoChem System by Naicker Scientific, based in Gloucestershire, England, was named the winner for its innovative use of microwaves and ultrasound to generate millions of microbubbles in melted lunar ice.

The extreme temperature and pressure created within each micro bubble generates free radicals (unstable atoms which are highly chemically reactive) which effectively removes contaminants.

The Aqualunar Challenge is a £1.2 million international prize funded by the UK Space Agency’s International Bilateral Fund.

Nasa has set the goal of establishing a permanent crewed base on the Moon by the end of the decade. Its Artemis programme is supported by the UK Space Agency through its membership of the European Space Agency.

Panel chairman Meganne Christian of the UK Space Agency said the challenge was required as "astronauts will need a reliable supply of water for drinking and growing food, as well as oxygen for air and hydrogen for fuel".

Lolan Naicker, technical director of Naicker Scientific said: "Imagine digging up the soil in your back garden in the middle of winter and trying to extract frozen water to drink. Now imagine doing it in an environment that is -200°C, a nearly perfect vacuum, under low gravity, and with very little electrical power. That’s what we will have to overcome on the Moon.

"If we can make the SonoChem System work there, we can make it work anywhere, whether that’s on Mars’ glaciers, or here on Earth in regions where accessing clean water is still a challenge."

The UK's Science Minister, Lord Patrick Vallance, has said many of these ideas suggested during the challenge could not only fuel future space exploration, but also help improve lives and solve water shortages on Earth.

Naicker Scientific was awarded the £150,000 first prize.

Frank, by father-and-sons team RedSpace, and AqualunarPure, from a team at Queen Mary University – both from London – were named runners-up.

AqualunarPure's system would use a reactor to melt lunar ice to separate the dust and rock particles, then heats it to more than 373°C at 220 bars of pressure to turn it into “supercritical water” – not a solid, liquid or gas, but a fourth state that appears like a thick vapour – in which oxidation will remove all the contaminants in one step.