In Urinetown: The Musical (a multiple Tony award winner), a 20-year drought caused private toilets to be banned, forcing people to use public toilets owned by Urine Good Company. Anyone who doesn’t pay (or tries to use a tree for free) is sent to a penal colony called Urinetown and never seen again. In Urine Town: The Moonbase, the European Space Agency (ESA) realizes it will be difficult (not to mention expensive) to take building materials to the Moon, so it has develop a way to combine moon dirt and human urine to make building materials. Will astronauts who refuse to pee be sent to the dark side?

“Urea can break hydrogen bonds, and therefore reduces the viscosities of many aqueous mixtures. Since urea is the second most abundant component in urine (after water), it is readily available anywhere there are humans.”

Everybody pees, so why not figure out a way to use it? That’s the idea behind “Utilization of urea as an accessible superplasticizer on the moon for lunar geopolymer mixtures,” a study published in the Journal of Cleaner Production. Urea is mostly nitrogen, highly soluble, non-toxic and neither acidic nor alkaline. In 1828, German chemist Friedrich Wöhler synthesized urea in the lab, making it the first substance considered to be an organic byproduct of life to be made from inorganic materials. Since then, it’s been used primarily for fertilizer, wood resins, explosives, animal feed, ice melting, dish soap (ewww!), a browning agent for pretzels (EWWW!), tooth whitening (beyond ewww!), topical dermatology creams and (ironically) as a diuretic to promote the production of urine. While space station astronauts recycle their urine (retrieving over 75% of the water), they currently dispose of the urea.

Researchers at Østfold University College in Norway considered the use of urea in wood resins when looking for ways to make materials on the Moon into usable concrete. They found that urine urea can function as a plasticizer – a substance that promotes plasticity and flexibility and reduces brittleness. When added to a substitute for the Moon’s regolith (the loose soil, dust, broken rocks and other stuff on the surface), the urea helped soften the mixture and make it pliable so it could be molded into bricks or other building materials before hardening.

The tool for creating the materials would be a 3D printer, which could form a wide variety of materials. When tested on Earth, this geopolymer concrete was able to support heavy weights and actually got stronger as it went through deep freeze cycles similar to moon conditions. The study points out that the urea may not even have to be extracted from the urine (like on the ISS) because the water could help soften the regolith.

I run the only toilet

In this part of town, you see

So, if you’ve got to go

You’ve got to go through me

It’s a privilege to pee

Water’s worth its weight

In gold these days

— It’s a Privilege to Pee (from Urinetown: The Musical)

Will the ESA take the lead on building bases and towns on the Moon and force American astronauts, Russian cosmonauts, Chinese taikonauts and other moon residents to use their rest rooms to reclaim urea … or else?