Chris Hadfield

As of this writing the current commander of the International Space Station is Pavel Viogradov, a veteran Russian cosmonaut in the top 20 of the list of people with most time in space. This post is about the commander who immediately preceded him, Chris Hadfield. Mr. Hadfield is a Canadian astronaut and a veteran of three spaceflights, but is most famous for making wonderful videos while in space. You can read more about him here:
Chris Hadfield

Before he became an astronaut Hadfield made his living flying fighters, first intercepting Soviet bombers over the Canadian arctic, and then testing the airworthiness of new aircraft for NATO forces in California. He flew over 70 types of aircraft before being selected to fly spacecraft as well. Since this should be sufficient to identify Mr. Hadfield as a badass, I will now direct your attention to the Reddit AMA he conducted while in space. This should be sufficient to convince you that he's a cool dude.

Since I previously made a claim about his videos, here's a brief proof by selected examples. First, a short film on the strange ways water behaves in microgravity:

Want to know more about the practical effects of fluid dynamics in weightlessness? In that case, this video might be to your liking as well:

Here's one just because it involves Russian space pajamas. Which apparently are a thing:

And finally his true magnum opus, which needs no introduction other than Bowie's in spaaaaaaaace: