The Rosetta Mission - How to orbit a comet

Long explanation short: it's extremely hard to orbit a object with very very very little gravity so it takes a lot of course correction to adjust it where you orbit it.

The most amazing part about this is that fact that we were even able to do this at all. Create a working satellite, launch it to an infinitely small target millions of miles away that is traveling at tens of thousands of miles per hour, and somehow manage to get it to orbit around it.

God, imagine the calculations that had to be done. Even one wrong number and it would all have been for nothing.

Despite how completely stupid humans can be, stuff like this is simply amazing.