Crew members on the space station have experienced difficulties with the toilet in the Zvezda service module, NASA said in an update Tuesday.

The New York Times said a NASA status report noted last week that the system for collecting liquid waste in the Russian-built module was not working. The crew has attempted to make repairs but has been unable to bring the toilet back into full operation, the newspaper said. The crew is now using the toilet on the Soyuz capsule attached to the station.

Discovery is scheduled to launch Saturday on its mission to the International Space Station.