You know what it's like when you need the loo and can't find one close by, so imagine being stuck in space with a broken toilet!
Well that's what's happened to the astronauts on the International Space Station.
The crew first realised something was wrong a few days ago, when they heard a loud noise and the fan stopped working.
But help is on the way - a new pump is being sent into space by shuttle, which should reach them on Saturday.
At the moment, one of Nasa's staff is rushing from Russia to Florida with the spare parts before the shuttle launch.
One of the astronauts said: "Clearly, having a working toilet is a priority for us."
But don't worry - they won't have to hang on that long to go to the toilet, as there are others on the space station they can use.