My odyssey to become an astronaut kind of started in grad school, and I was working, up at MIT, in space robotics-related work; human and robot working together.

I was the first person to tweet from space, but now every astronaut tweets from space and does Instagram and Snapchat and Face - they have Facebook going. I think it's more of a personal relationship they have with space now. They see it as more obtainable than me watching my superhero Neil Armstrong and Buzz Aldrin walking on the moon. It's like, there's no way I can do that.

I think most astronauts are not risk takers. We take calculated risks for something that we think is worthwhile.

I applied to be an astronaut four times. I was rejected three times before I was accepted. So, it's about that, not - following your dream and not giving up.

Viewing our planet was so compelling. Words like beautiful and awesome just don't do it justice. I felt that I was looking at a paradise. I was looking at heaven. I can't imagine any place being more beautiful than our planet and how lucky we are to be able to live here.

To become an astronaut is not a question of being the best at something or things coming easy to you, but it's being a person that can work with others and not give up. And, for me, that was part of it too.

My odyssey to become an astronaut kind of started in grad school, and I was working, up at MIT, in space robotics-related work; human and robot working together.