A spacecraft could withstand launch, vacuum and the journey back to Earth from the moon, but would run into trouble in solving one of humanity’s oldest engineering problems: what to do with bodily waste when there is no gravity. This became clear during a very early moment in Artemis II, as Orion’s Universal Waste Management System temporarily lost functionality due to the problem with one of the controllers, impacting the toilet fan. The problem was fixed by NASA afterwards, but the failure revealed an easily joked about problem which is difficult to solve technically. On the small spacecraft traveling beyond low Earth orbit, sanitation equipment cannot be considered as an accessory. Instead, it’s a crucial element of the life support system, crew workload, privacy design and overall flight longevity.
Orion was designed using the NASA developed Universal Waste Management System a unit which is supposed to be highly versatile and more universal than previous designs intended for space stations. It is said to be 65 percent smaller and 40 percent lighter compared to current ISS toilet while using the airflow technology of pulling waste out which is replacing gravity. Once you open the lid, the airflow becomes active automatically, odor is better controlled, and the waste is being drawn to the right place.
The technology also reflects many astronaut complaints about awkward and time consuming nature of earlier systems. Now it became possible to use both urine funnel and the toilet seat together a feature introduced specifically following feedback from astronauts, and particularly women. Foot holds, restraints and hand grips replaced more complex positioning methods, and Orion also introduces a small private bay for hygiene activities that Apollo crews lacked. This detail has more importance than one may initially think.
Historical examples from space show us quite clearly that any minor habitability issue scales up to an operational problem if the mission becomes prolonged enough. Apollo crews faced bags, leakage, and notorious unplanned drifting of human waste. In ISS, urine is one of the sources of water recovery in a closed loop process that makes the station self sufficient. According to NASA, the ISS manages to recycle almost 90 percent of all water based fluids including urine and sweat. Artemis II will likely require less water recollection since it’s a relatively short mission, but it still needs a reliable toilet system inside the limited volume of the cabin.
The temporary malfunction also illustrated the differences between the demonstration and established mission. The design of Orion is way more sophisticated compared to those improvised solutions used by the Apollo program. However, even this advanced toilet is based on precisely integrated air flow, fans, and collection hardware, and a failure of just one controller forced the crew to use contingency equipment. Such “routine” operations are still extremely important in deep space missions because each potential solution consumes precious crew resources.
This is why design of such subsystems has become one of NASA’s priorities alongside with many other engineering goals. Future missions will require quieter systems, lower maintenance efforts, high efficiency, and, above all, extensive fluid management systems. NASA has set a long term target to improve the performance of their future exploration vehicles far beyond today’s ISS capabilities, because unlike ISS crews, Mars expedition will not be able to receive frequent resupplies from Earth. The toilet glitch during the flyby to the moon may not cause serious problems. It will be a serious test of systems if it happens on a multi year flight.
Orion’s minor malfunction in the early mission didn’t alter anything. However, it clearly reminded us that a deep-space vehicle is defined by far more unglamorous parts of engineering than propulsion, protection and guidance systems. Human exploration is still impossible without one simple truth a space vehicle has to cope with daily biological processes of its inhabitants efficiently enough.