Weightlessness was wonderful, and I was surprised at how natural it felt.

At this point I thought 'We made it,' by which I meant 'We survived.' I also was acutely aware that my childhood dream of flying into space had just come true.

I lay on my back, surprised at how calm and focused I felt, strapped to four and a half million pounds of explosives.

And in that moment, I was hit with the realization that this delicate layer of atmosphere is all that protects every living thing on Earth from perishing in the harshness of space.

Ideally, the ISS program will just be one more incremental step on an expanding, incredible journal of exploration and understanding, taking us higher and farther.

The ISS would not be the incredibly capable orbiting research facility it is today without either Russians or Americans, just as it couldn't have been built without the Canadian arm used in its construction.