The astronauts who will depart the International Space Station on Sunday will be stuck using diapers on the way home because of their capsule’s broken toilet.

NASA astronaut Megan McArthur described the situation on Friday as “suboptimal” but manageable. She and her three crewmates will spend 20 hours in their SpaceX capsule, from the time the hatches are closed until Monday morning’s planned splashdown. “Spaceflight is full of lots of little challenges,” she said during a news conference from orbit. “This is just one more that we’ll encounter and take care of in our mission. So we’re not too worried about it.”