I don't know if you're aware but one our own, Canadian Astronaut Chris Hadfield has become an awesome ambassador not just for Canada but for NASA. Not only is he a pretty cool guy but he's hooked into social media like no other astronaut before. He's tweeted pictures of the earth, held an AMA on Reddit, even helped compose and perform the first song in space. Here he's going to show you how to make a sandwich in space and explain why they use the ingredients they do. Enjoy!