In 2014, the European Space Agency's Rosetta probe will enter orbit around a comet -- the first time this will have ever been done -- and then drop a lander on it -- and oh yeah, that's the first time this will have ever been done, too.
I'm pretty excited about this mission, and NASA and ESA have put together this really well-done video explaining the mission and what it'll do:
I found this on the Rosetta Blog which has been a great source of info over the years. Rosetta has already been a very successful mission without even having reached its target yet: it's swung by Mars, took stunning closeup images of the asteroid Lutetia, flew past another asteroid called Steins and got nifty pix of that, and also flew past Earth --twice! three times! -- to steal some of our orbital energy to propel it on its way... and snapped one of my favorite pictures of Earth ever taken (seriously, click that link; have you ever seen a crescent Earth that beautiful?).
And yet all that is a prelude to what's coming in a little over two year.
And if you can't wait, the folks at JPL created a game called Comet Quest (for iPad and iPhone) where you control the Rosetta probe as it orbits the comet. You have to deploy the lander, identify and avoid hazards (like jets and rubble from the comet), an communicate with Earth to transmit your results. I played it for a while on the iPad and I have to admit it was fun. Give it a shot!