We’ve been launching things into space since the late 1950s, and while the aspirational talk about exploring the final frontier keeps getting louder, we’ve been a lot quieter about the fact that all those rockets left a vast, orbiting field of high-speed trash which poses increasing hazards to future missions. And while we think we know how to clean it up, actually doing it requires negotiating some very thorny politics, and establishing some very new and different priorities.