There's a lotta junk in space, and figuring out how to remove it all has been a popular topic in the space community. Here's a new idea out of Russia: sink $2 billion into a roaming, pod-shaped craft that'll safely dispose of 600 dead satellites.
Energia, Russia's key space corporation tasked with manufacturing the country's spacecraft, plans for the nuclear-powered pod-craft to latch onto satellites (it's unclear how, but we'd like to think it chomps onto them Pac-Man style) and then remove them from orbit, either by sending them to burn up in the atmosphere or splash down in an ocean somewhere. The company plans for the pod to be ready for testing by 2020, and for the real deal to start deorbiting satellites by 2023 and to operate for 15 years. With said $2 billion budget behind it, it may just be the most serious effort right now to clean up orbital debris.
As if that isn't a grand enough task, Energia is also drafting up plans for a "space interceptor" that could sally forth if a dangerous object on a collision course with the planet was detected. So, from the sounds of it, Russia is our best bet when it comes to combating space junk and hostile aliens.