Astronauts will face a host of obstacles when they visit the Moon again. There’s powerful radiation, wild temperature swings, and challenging gravity to deal with. There’s also dust and lots of it. Moondust was a hazard for the Apollo astronauts, and future lunar astronauts will have to contend with it, too.
What if they turn some of that dust into solid surfaces to drive on?
When Apollo 11 was preparing for the first Moon landing, they faced a lot of unknowns. They knew from orbital images that there was a lot of dust, but mission planners didn’t know how much or how deep. There was a risk of sinking into it. So serious was the risk that the lander had three dust-sensing probes extending downward from three of the lander’s feet. If they sank too deeply into dust, the landing could be aborted.
Apollo 11’s Columbia Module photographed the Lunar Module Eagle in a landing configuration. The long rod-like protrusions under the landing pods are lunar surface sensing probes. Upon contact with the lunar surface, the probes sent a signal to the crew to shut down the descent engine. Image Credit: NASA
They didn’t sink in, as we all know, but the dist did cause problems, and the Apollo astronauts weren’t on the lunar surface for very long.
Since then, we’ve learned a lot about lunar dust and the obstacles it imposes on exploration. The ESA will eventually establish a sustained human presence on the Moon so that our natural satellite can be more fully explored. Eventually, in-situ resource development will form part of the mission.
All that activity means the astronauts will need transportation, reliable transportation that lasts a long time. And that means somehow dealing with the fine, clinging dust that coats the Moon. Rather than engineer surface vehicles that are somehow impervious to dust, the ESA thinks they can melt the dust where it sits, forming a hardened driving surface. Will that solve the problem?
NASA modelling shows that when a spacecraft touches down on the lunar surface, it can send tons of fine dust above the surface before eventually settling. Due to the Moon’s low gravity, it can take a long time to settle. That wasn’t a huge problem for Apollo’s small landers, but future landers will be much larger. All that dust could foul the surfaces of landers and cause all kinds of problems. But what if the dust on landing areas and travelling surfaces could be melted with high-energy lasers?
The ESA decided this is a tactic worth pursuing. Their PAVER (paving the road for large area sintering of regolith) program investigated the idea. PAVER is a consortium of European companies and organizations. In controlled tests on simulated lunar regolith, they used a 12-kilowatt CO2 laser to melt simulated moondust. It created a smooth, glassy surface that has potential as roadways, landing areas, and other operational areas from the Moon’s plentiful dust.