Many miles above the planet orbits a space ship. It orbits, silently, unimaginably quickly, watching all that happens below.
Its the ISS, the International Space Station. And on board currently is Commander Chris Hadfield, a Canadian Astronaut who regularly posts updates about his activities and roles to various places on the internet.
One of these caught my eye, when a student asked him how he became a spaceman. His reply was simple (and beautifully drawn here by Zen Pencils http://zenpencils.com/comic/106-chris-hadfield-an-astronauts-advice/ )
Follow your dream and every day check that those things you are doing will get you there, step by step.
This is the same for everything we do, not just becoming an astronaut. Constant, tiny changes can lead to huge differences eventually.