As of this posting, the International Space Station has been continuously occupied for 12 years and 125 days. In that time, the orbital outpost has had more than its fair share of awesome tenants, but astronaut Chris Hadfield has got to be one of our favorites.
Hadfield arrived at the ISS last December, and will become the first Canadian to command the station when the crew of Expedition 35 takes over later this month. Since he's been aboard, he's tweeted hundreds of gorgeous photos of Earth, taught us how to make sandwiches in space and swapped tweets with the cast of Star Trek. Dude is excellent, all around.
A few days ago, Hadfield hosted an AMA on reddit, wherein he was asked if he had any advice for an aspiring astronaut. Here is his response, as illustrated by the always-awesome Zen Pencils: