At the moment, astronauts just launch their used clothes into orbit.

Ever wondered how astronauts aboard the International Space Station do their laundry?
Well, they don’t, and the National Aeronautics and Space Administration (NASA) is working hard to solve what is one of the most thorny tasks in space – washing clothes.
The space agency is planning to conduct a series of experiments using specially designed detergents from Procter and Gamble (PG.N) to find a long-term solution to the problem, the U.S. consumer goods giant said on Tuesday.
The vital nature of water on space missions has meant that astronauts have simply jettisoned used clothes, happy in the knowledge they will disintegrate as they re-enter the atmosphere.
As a result, NASA sends 160 pounds of clothing per crew member to the International Space Station per year.
For the longer run, with the U.S. agency and Elon Musk’s Space X eyeing manned missions to Mars, there needs to be a more sustainable solution.