How do you test Moon landers, or lunar excavation and construction processes? Get some fake moon dust, of course.
The layer of dust covering the Moon (in technical terms, the lunar regolith) is dangerous. I’ll talk about some of the weird properties of moon dust in a later post, but one big issue is the fact that dust from the moon’s surface is sharp. Absent wind or other meteorological processes like the ones that smooth earthbound materials, moon dust is especially jagged. It played merry hell on astronauts’ equipment during the original Moon landings, to the extent that any future lunar exploration has to find a way to ameliorate its many adverse effects.
(This, by the way, is also a major problem with any Martian exploration in our future. Imagine getting jagged gritty lunar or Martian dust in your lungs? It would make pneumonoultramicroscopicsilicovolcanoconiosis look like a walk in the park.)
It is surprisingly difficult to experiment with lunar dust. While the various human missions to the Moon brought back hundreds of kilograms of the stuff, that jagged grittiness has since worn through the (extremely advanced and expensive) seals of the containers. All the samples from the old lunar exploration are now contaminated and therefore relatively useless.
So what do you do? Well, you fake it.
By that I mean you create a physical simulation of lunar dust, crushing up similar Earth rocks and sifting them until you get a rough analogue of the real deal. NASA has a pile of the stuff that they use to test prototype lunar rovers, and a few private companies have tried to make their own batches of “lunar regolith simulant.” This material is useful if you want to plan for any kind of permanent lunar base, for example if you want to work out how to make concrete out of Moon materials.
We actually have some good ideas about how to make lunarcrete, by the way, assuming that we resolve the issue of water. Not just how to get water to the Moon, but how to prevent it from immediately disappearing if exposed to the lunar lack-of-atmosphere. It would be a lot cheaper than flying all the construction materials up there from Earth.
(End note: did I make this post just so that I’d have an excuse to work pneumonoultramicroscopicsilicovolcanoconiosis into a sentence? Mmmmmmaybeeeee…)