A space telescope built with expertise from Cardiff University is coming to the end of its mission.
The Herschel Space Observatory is about to make its 50,000th measurement using the biggest mirror ever to be sent into space.
It's been helping transform our understanding of the Universe and how stars are formed. But its coolant is due to run out in March and scientists are deciding what happens next. One idea is to crash it into the Moon.
Andrew Jones reports.
Pictures: ESA/AOES Medialab
Herschel has a fixed end-date because its three instruments all need to be cooled to very low temperatures. "That cooling is provided by a big tank of liquid helium on board. The helium is gradually boiling away, and as planned, it will eventually run out and the instruments will stop working". Some people don't like the idea because they think the Moon should not be contaminated by crashing a spacecraft into it, some other people think Herschel is such a lovely spacecraft that shouldn't be destroyed by crashing into a rock like the Moon!" "But most of the members of my team are very much in favour. We don't regard the spacecraft as the final legacy... we regard the data and the science [as the legacy]. If we can do a little bit more at the end, we'd find that very pleasing.