NASA is offering up to $20,000 to anyone who can design a better space toilet for astronauts sent to the moon

• NASA needs a new toilet for going to the moon — one that will work for all astronauts and function both in microgravity and on the lunar surface.
• The agency is crowdsourcing ideas for the toilet with a "Lunar Loo" challenge. The top prize is $20,000.
• Historically, most space toilets have been little more than a bag and a hose with a vacuum.

The last time humans landed on the lunar surface, in December 1972, they were all basically wearing diapers.

That's because NASA never really bothered to design a proper toilet for the Apollo moon missions. Instead, astronauts peed into roll-on cuffs, pooped into bags, and used space diapers when they ventured out of the spacecraft in their big bulky spacesuits.

"Defecation and urination have been bothersome aspects of space travel from the beginning of manned space flight," said an official NASA report on the Apollo missions published in 1975.

Nearly five decades later, as the US prepares to launch astronauts to the lunar surface by 2024, the space agency is hoping to do things a little more comfortably.

"The astronauts were adamant that they do not want to go back to the Apollo bags," Mike Interbartolo, who's part of NASA's lunar-lander engineering team, told Business Insider.

So this time around, NASA is crowdsourcing a new toilet design for the Artemis moon lander, launching a "Lunar Loo" contest on HeroX.

"We need a toilet that needs to work for seven days on the surface of the moon, as well as during that transit time to and from the moon," Interbartolo said.

That means the toilet system must be functional in both the microgravity of space and lunar gravity, which is about one-sixth Earth's gravity. The toilet must also be usable for all astronauts, regardless of sex — something the first space bathrooms decidedly were not.

Going to the bathroom is space is not glamorous

NASA hasn't changed much about how astronauts relieve themselves in space since it designed its very first toilets.

The first US space toilet, designed for Skylab in the 1970s, was essentially a hole in the wall. Today on the International Space Station, astronauts use a funnel equipped with a fan that suctions their pee away, but they still have to bag up their poo. They've described it as one of the most bothersome aspects of living in space.

Russia designed the newest space toilet in operation on the ISS — a $19 million contraption that's been there since 2008. And SpaceX's new and mysterious commode on its Crew Dragon spacecraft likely employs a basic hose-and-bag system, much like what's on Russia's Soyuz spacecraft.

But 2020 is shaping up to be a banner year for US space toilets: A new urine-recycling model for the ISS is in the works and set to arrive there before the end of this year.

The moon toilet, however, will be a bit trickier to develop. In addition to needing to work in both microgravity and lunar gravity, it needs to be a lot smaller and lighter than the existing space toilets so that NASA doesn't have to waste a bunch of fuel rocketing it up and down to the lunar surface.

That's where the "hackers," "makers," "basement tinkerers," and "garage mad scientists" around the world come in, Interbartolo said.

"We want that different perspective over the next couple months of this challenge to really kind of open our eyes to the unknown unknowns that, since we're so tightly focused on what a space toilet is, maybe there are different things that we're not aware of out there," he said.

It's a lot like NASA and HeroX's 2017 Space Poop Challenge, in which Dr. Thatcher Cardon, a flight surgeon and US Air Force colonel, invented a way to go to the bathroom inside a spacesuit without a diaper and took home $15,000.

The new space toilet must be small, quiet, and easy to use

With a mass of no more than 15 kilograms (about 33 pounds) and a maximum volume of 0.12 cubic meters (roughly 4.2 cubic feet), the new space toilet would be smaller than the typical minifridge.

NASA's guidelines for the challenge say the toilet should be easy to clean and maintain and have a "5 minute turnaround time or less between uses." Competitive toilet designs will be easy for the astronauts to use, and they should conserve water while containing smells.

"There's potential that there will still be some sort of bag within the toilet system for the microgravity scenario, just because the body doesn't let go of some of that stuff, you know, as easily," Interbartolo said.

NASA's guidelines also say the new toilet must:

• Function in both microgravity and lunar gravity.
• Have a mass of less than 15 Kg in Earth's gravity.
• Occupy a volume no greater than 0.12 m³.
• Consume less than 70 Watts of power.
• Operate with a noise level less than 60 decibels (no louder than an average bathroom fan).
• Accommodate both female and male users.
• Accommodate users ranging from 58 to 77 inches tall and 107 to 290 lbs in weight.

"Bonus points will be awarded to designs that can capture vomit without requiring the crew member to put his/her head in the toilet," NASA said.

The deadline to submit toilet designs is August 17 at 5 p.m. ET. Prizes are $20,000 for first place, $10,000 for second, and $5,000 for third.

Kids and teens from 11 to 18 can also submit their ideas for the moon toilet, but they're competing for public recognition and some NASA swag, not cash.

"The big thing is it can't break the laws of physics," Interbartolo said.