Bodhan Chiravuri Designs Toilets For Astronaunts
There are several privileges and commodities we take for granted on Earth, and being able to use the bathroom is one of them.
In order for NASA to return to the moon in 2024, their engineers need to design a toilet that works in space. Rather than trying to solve this conundrum themselves, NASA created the Lunar Loo challenge in the summer of 2020. The task was set out: create a toilet that works both in microgravity and lunar gravity. Hopkins School’s very own Bodhan “Bodhi” Chiravuri, ’26 won third place honors in the NASA Lunar Loo challenge.
Chiravuri’s toilet needed to be able to work with two forms of gravity. Creating a toilet for space has proven an issue for NASA because of the two types of gravity astronauts will encounter on their trip. NASA explains microgravity as, “what is generally considered ‘zero-g’ and is experienced as weightlessness.” This is different from lunar gravity, which, “is approximately one-sixth of Earth’s gravity, so urine and feces will fall down.”
Chiravuri named his toilet the “CosmoCommode.” In order to battle gravitational differences, he designed the CosmoCommode to, “create its own ‘artificial’ gravity by spinning around and creating a rotational centrifugal force (RCF) for the entire system which is the astronaut, the human waste, and the toilet itself.” He derived his idea from the Zero Gravity carnival ride: “based on my readings and experience with the Zero Gravity ride, I knew that rotation produced artificial gravity, and went from there. I spent some time researching, designing, and redesigning before I came up with what I have now.” On the Zero Gravity ride, “The entire mechanism is spinning around the central axis. In the same way, my toilet will spin but will do so vertically.”
Chiravuri details the science of the CosmoCommode: “the artificial gravitational force i.e. the rotational centrifugal force is proportional to the radius of the system and the speed of spinning. RCF = 1.18 X 10-5 X Radius (cm) X RPM2.” The CosmoCommode requires its user to be strapped into the device in order for it to create enough rotational centrifugal force. “The one thing I was worried about was the astronaut getting dizzy,” he notes, “but Astronaut Tim Peake performed an experiment that proved that you can’t get dizzy by spinning while in space, due to weightlessness.”
Another important element in the creation of space toilets is the disposal process. Space shuttles lack plumbing systems, so Chiravuri needed to devise a way to efficiently seal off all waste in a secure and disposable manner. On the Cosmo- Commode, “as soon as the astronaut is done, they will press a button that makes a containment lid slide over the waste chamber in the toilet. After this, the toilet comes to a stop and the astronaut can get off. The waste is then suctioned out.”
Chiravuri stated that the most difficult part of designing his toilet was the sizing restrictions. NASA required that all submissions be lightweight and compact, weigh less than 15 Kg in Earth’s gravity, have a volume no greater than .12cubed, and be quieter than the average bathroom fan. “I sketched it up on my iPad and used Procreate to create my design,” he recalls. “I kept refining it even after that. I did have to stick to strict sizing guidelines, which was hard considering all of the mechanics that I had to fit in it.” Ultimately, he was able to incorporate all his design elements in a model even smaller than the guidelines.
Chiravuri heard about this challenge through his previous research on SpaceX launches. He remembers, “My dad and I had just watched the SpaceX launch of astronauts last summer and I was surfing the internet to learn more about SpaceX and NASA when I came across the Lunar Loo Challenge. It was a fun way to spend our time learning about space toilets and how they work.” Chiravuri shared he has a knack for robotics and design, and that he “always loved to build things, starting with Legos and models but [has] also liked to take things apart. I more recently started to draw, and have enjoyed creating blueprints and designs for some of my projects.”
Chiravuri was just one of almost a thousand contestants competing in the Lunar Loo challenge. Each competed within their specific age division. He reminisces, “There were a lot of other amazing ideas and designs as well. One of my favorites was one that used circular airflow.”
The prize for placing in the top three was public recognition for the contestants’ innovations and NASA merchandise, but that’s not all Chiravuri got out of the competition. “It was a great experience,” he says. “It gave me the opportunity to put together some of my skills. The most rewarding part of this experience was the recognition I got. The NASA swag bag was pretty nice too. I definitely plan on doing something like this again. It was a lot of fun and I learned a lot in the process.”