 They've kind of agreed to keep running the space station until the end of the decade, and then they're looking to get out and do different things. And the question is, what do you do with the space station when you get to that point? They can't just leave it circling the Earth, because eventually it'll fall into the atmosphere. And it's big. It's 430 tonnes. It's the size of a football pitch. That's going to cause quite a bit of damage, unless they do it in a better, safer, more calculated way.