Nasa's first new space toilet in decades — a US$23 million ($34.6m) titanium toilet better suited for women — is getting a not-so-dry run at the International Space Station before eventually flying to the moon.
It's packed inside a cargo ship set to blast off late on Thursday (Friday NZ time) from Virginia in the US.
Barely 45kg and just 71cm tall, it's roughly half as big as the two Russian-built toilets at the space station.
It's more camper-size to fit into the Nasa Orion capsules that will carry astronauts to the moon in a few years.
Station residents will test it out for a few months. If that goes well, the toilet will be open for regular business.
SpaceX is now launching astronauts to the space station and Boeing is less than a year from sending up its first crew, so more toilets are needed. The new one will be in its own stall alongside the old one on the US side of the outpost.
The old toilets cater more towards men. To better accommodate women, Nasa tilted the seat on the new toilet and made it taller. The new shape should help astronauts position themselves better, said Johnson Space Centre's Melissa McKinley, the project manager.
"Cleaning up a mess is a big deal. We don't want any misses or escapes," she said.
Let's just say everything floats in weightlessness.
Like earlier space commodes, air suction, rather than water and gravity, removes the waste. Urine collected by the new toilet will be routed into Nasa's long-standing recycling system to produce water for drinking and cooking.
Titanium and other tough alloys were chosen for the new toilet to withstand all the acid in the urine pre-treatment.
Going to the bathroom in space may sound simple, but "sometimes the simple things become very difficult" without gravity, said Nasa astronaut Mike Hopkins, commander of the second SpaceX crew, due to launch October 31 from Kennedy Space Centre.
Although the old design isn't that hard to use, subtle design changes can make all the difference for women, notes Nasa astronaut Shannon Walker, a former space station resident who's also on the next SpaceX crew.
"Trust me, I've got going to the bathroom in space down, because that is a vital, vital thing to know how to do," she said.
The typical space station population will go from six to seven with the next SpaceX flight, and even more when non-professionals like tourists start showing up as early as next year. Astronauts normally stay six months.
The last time Nasa ordered a new toilet was in the early 1990s to accommodate two-week space shuttle missions. The agency contracted with Collins Aerospace to provide the latest model; the company also worked on the shuttle toilets.
Also in the 3600kg shipment aboard Northrop Grumman's Cygnus capsule are air tanks to make up for a slight space station leak, radish seeds for greenhouse growing and a cinematic 360-degree VR camera for you-are-there-spacewalk shots.
Perhaps the most unique payload is Estee Lauder's newest wrinkle serum. The cosmetics company is paying US$128,000 for an out-of-this-world photo shoot, part of Nasa's push to open the final frontier to marketing, industry and tourism.
The 10 bottles will remain sealed until returned to Earth early next year.