Mission Specialist Christina Koch reported a burning smell from the toilet hygiene bay on the night of Day 3, resembling "an old electric heater switching on." Flight controllers suspected orange insulation on the hygiene bay door and cleared the system for continued use. The toilet has now generated two separate anomaly reports since launch, distinct from the Day 1 fan fault .

Second toilet fault reported on Day 3
Koch reported a burning smell from the toilet hygiene bay, the second separate toilet anomaly in 72 hours.
Second toilet anomaly since launch; cleared as non-critical.
Deep Analysis
The toilet on Orion is not optional equipment. In deep space, a functioning waste management system is mission-critical: there is no alternative and no way to repair or replace it from outside the spacecraft. Two separate faults since launch, both cleared by ground teams, mean the system is working but has generated more anomaly reports than NASA publicly anticipated.\n\nNeither fault threatened the mission. Both produced data about how the system performs in the actual deep-space environment, which is harder to replicate on the ground than almost any other system test.
The Orion waste management system was tested extensively at NASA's Johnson Space Center, but thermal and vacuum conditions in translunar space differ from ground-based test chambers in ways that affect seals, fans, and insulation materials. The burning smell consistent with heat-activated insulation is a known failure mode in enclosed electrical systems exposed to temperature cycling.
NASA's anomaly log for crewed missions records all fault lights, creating a reliability dataset that informs refurbishment protocols for Artemis III. Two toilet anomalies in 72 hours will register as a priority for hardware engineers reviewing the post-mission data.
- Consequence
Two separate toilet system anomalies in 72 hours will flag the waste management system for priority hardware review before Artemis III.