Humans are currently (as in literally right now, the morning of 11/12/2014) trying to land a robotic probe on a comet for the first time.
Aside from the incredible technical challenge, the Rosetta Orbiter and Philae Lander are just cool; the lander has harpoons (space harpoons!) and thrusters and drills. Plus, the graphic supplied by the ESA (yeah, official graphic from the European Space Agency) in this article has an Imperial Star Destroyer in it for scale. That might be my favorite part.
The linked article has nice graphics and information explaining the mission, timeline, and links to more info. Good Luck Rosetta team!