I think most officeinsight readers are familiar with Duravit AG, the German manufacturer of designer bathroom fixtures. When I recently read that Franziska Wülker, a young female development engineer at Duravit, had won 3rd prize in a NASA sponsored design competition to design a new space toilet, “The Lunar Loo,” I knew it was a story I had to write.
I’ve been a rocket and space nut since childhood. When I was in middle school (we actually called it junior high those many years ago) my nephew and I – he’s only two years my junior – started a rocket club designing, firing and sometimes exploding rockets fueled by our self-made rocket fuel of potassium nitrate and sugar.
Now, I follow the daily triumphs and set-backs of SpaceX on YouTube as they hurtle toward the design, development and deployment of Starship and Super Heavy, a launch and return system where the two rockets work together to carry people and cargo to and from the moon (and eventually Mars). Each one of them is the biggest rocket since the Saturn V carried Apollo astronauts on the first leg of their journeys to the Moon, and together, WoW!
The Artemis Program is NASA’s project with the stated goal of putting “the next man and the first woman” on the moon by 2024. And the agency has pulled out all the stops to improve all systems in our current space program.
The existing systems for separating astronauts from their bodily wastes leave a lot to be desired. For one thing, most of them were designed when all astronauts were males; and they aren’t super effective designs even for men. So NASA put out a call for the design of the next generation of space toilets with a $35,000 prize for the top three designs. More than 2,000 companies and individuals sent in entries. Ms. Wülker of Duravit won 3rd.
When notified of the results of the competition, Thomas Stammel, Chief Technical Officer at Duravit AG, was delighted, and said: “We are extremely proud that Franziska Wülker was able to conceive and complete such an ingenious project alongside her regular work. Third place is a considerable achievement that is also a testament to our expertise in the field of toilet technology.”
The Duravit space toilet is comfortable to use for both male and female astronauts thanks to its optimized sitting geometry. The design includes filters that guarantee that neither unpleasant odors nor bacteria can escape into the cabin of the spaceship. The toilet system is self-contained, meaning that the safety of the crew is guaranteed even in the event of a power outage or problems with other systems of the spaceship. And in addition to its ingenious technology, Duravit’s design comes in well below NASA’s specifications in terms of weight and energy consumption.
“When developing toilets, we pay close attention to reliable flushing performance and good hygiene. As well as functionality and design, we are also always mindful of current issues such as water consumption. On our toilets designed for use on earth, we are naturally assisted by gravity, which causes the excrement to fall automatically into the toilet bowl. One of the biggest challenges in the construction of the Lunar Loo was rethinking everything to ensure that the functionality also worked in a weightless environment,” said Ms. Wülker.
Here are edited excerpts of my Zoom interview with Ms. Wülker.
How did you learn about the NASA competition?
“Well actually, I read about it in a German newspaper during the weekend, and the next Monday when I returned to work I had an email from my boss who had also read about the challenge and he asked, ‘Well don’t you want to join?’ And of course I wanted to join – it’s a very exciting topic!
“He knows that I like difficult challenges and a toilet that works in weightlessness as well as on the moon is quite a challenge. Most things we don’t even think about on earth like eating, washing your hair and going to the toilet are pretty difficult in space.”
Did the design brief specify how much of the time the Lunar Loo will be used in weightlessness vs on the moon?
“The 1st manned mission, Artemis 2, is only a lunar flyby, so the astronauts will be weightless for the entire mission. And even on Artemis 3, the first mission to actually land on the moon, two astronauts will stay in orbit around the moon while two land and stay for six and a half days. Right from the start the Lunar Loo will have to operate under both conditions.”
Did Duravit allow you to work on your entry during work hours?
“Yes, I could use my work time on the Lunar Loo and more importantly, I could use the resources I have at work. I have a computational fluid dynamics program so I could run simulations of the centrifuge to figure out which design works best and I could also use the design program.”
How does your design work?
“It has air suction to remove the excrement from the astronaut, similar to the current system, but then it goes into a centrifuge that spins very rapidly. The centrifugal force transports the excrement out of the centrifuge through holes in its side. Between the wall of the spinning centrifuge and an outer wall there is a helical screw that carries the excrement to a tank. If you have a salad centrifuge, you can imagine that the Lunar Loo works in a similar way, but with the helical screw to mechanically transport the excrement to the tank at the bottom.”
How does your system separate Urine from Solid waste?
“Separation of the two kinds of waste wasn’t a part of the challenge, so I decided to keep the design as simple as possible. Because we don’t have to separate, there’s only one transport system and only one tank, meaning fewer moving parts to maintain.”
Did you build any physical prototypes?
“No, but I built many digital prototypes and evaluated their performance with simulations. I did have one physical prototype if you consider the salad centrifuge as the basis of the idea of using a centrifuge to compensate for the lack of gravity. When I talked to my colleagues about the idea of the salad centrifuge, one colleague who keeps bees said, “Oh it works like a honey centrifuge!” So, I guess that’s another kind of physical prototype.”
So what will happen next? Will NASA commission a working model?
“I don’t know. I sent them all my data, so they have the 3-D models, all the simulations and the documentation I wrote. There were power usage and noise level requirements and size constraints. They have all my data on how these were met, so we’ll see if they come back to me with more questions. But I guess they will combine the good ideas from the three winners and eliminate the weak points of the solutions and come up with the final design.
“One of the requirements of entering the competition was that you wouldn’t patent any of your designs, so in effect all the designs are now in the public domain and NASA or anybody else can use the ideas.”
Congratulations, Franziska. I think winning 3rd place among 2,000 entries is a remarkable achievement and one you and Duravit can be extremely proud of. And I congratulate Duravit and your boss for giving you the latitude to work on the project using company assets and during working hours. This prize speaks very highly of both you and your company.
One last thought about the Lunar Loo: isn’t it a funny coincidence that for centuries the symbol for the outhouse has been the crescent moon?