'That was a wonderful toilet': Artemis 2 commander defends mission's lunar loo

Artemis 2's space toilet doesn't deserve the bad press it's gotten over the past two weeks, according to mission commander Reid Wiseman.

Wiseman took some time to defend Artemis 2's lunar loo on Thursday (April 16), during a press conference at which the mission's four crewmates — fellow NASA astronauts Victor Glover and Christina Koch and the Canadian Space Agency's Jeremy Hansen — discussed their historic mission.

"I just want to say, 100% point blank: That was a wonderful toilet," Wiseman said. "The toilet worked great."

As you probably already know, there were some waste-disposal issues on Artemis 2, the first crewed mission to the moon since Apollo 17 in 1972. But, Wiseman stressed, the blame doesn't lie with the toilet itself, which is a more compact version of the loo that flies on the International Space Station.

"The toilet flushed just fine, but then when the liquid went out the bottom of the toilet, it got clogged up in our vent line," he said.

That vent line carried urine from the toilet to the hull of Artemis 2's Orion capsule, named "Integrity." From there it was expelled into space, creating quite a spectacle.

"I mean, that is an interesting thing to see out the window," Wiseman said. "It's just like a billion little tiny flecks of ice heading out into deep space."

But the clog limited this venting activity, which meant the space toilet was out of commission for parts of Artemis 2, which launched on April 1, flew around the moon on April 6 and returned to Earth on April 10. After all, the toilet's tank could hold "under 10 urination events," Wiseman estimated.

(Number twos were not vented into space, by the way; Integrity's space toilet was designed to hold solid waste until landing.)

So, what caused the vent line to clog? At first, NASA thought ice might have blocked the vent nozzle. But the problem remained even after the area was heated internally and Integrity was tilted to expose the nozzle to the sun. The current thinking therefore centers on a chemical reaction, possibly one involving chemicals introduced into the wastewater to prevent biofilms from growing in it.

NASA won't know for sure until teams have had a chance to examine Integrity in detail, which they are doing now. But whatever the root cause turns out to be, Wiseman thinks the toilet team should be proud.

"Those great engineers that made that toilet, I don't want them hanging their head low. They should hang it very high," he said. "It was a great piece of gear."

His enthusiasm for the toilet is not surprising, as the privy was a big step up from previous moon missions. The Apollo astronauts didn't have a toilet of any kind — just a lot of handheld bags.