The disposal of waste is a problem on space missions. Until now, the waste that accumulates on the International Space Station (ISS), for example, has been disposed of by deliberately allowing it to burn up in the Earth's atmosphere. Adrian Schorowsky, Leni Termann and Lara Neubert - the winners of the Earth and Space Sciences prize - developed the idea of melting down plastics on board the station in order to produce new material - known as filament - as a raw material for use in 3D printers. Following theoretical considerations, the young researchers tested the melting down of polyethylene, which is frequently produced on the ISS. Even if the processing of the plastic into a new filament did not yet work as planned, they are convinced that this concept will make it possible to recycle much of the waste on board in the future.