True facts: You're probably not going to be a Mars colonist. Heck, getting Moon-based habitats built and populated is going to be hard without factoring in your extra-terrestrial desires. You can, however, compromise by sending your name into the stratosphere, an opportunity NASA is providing with it's upcoming Orion test flight.
Once you hit up the submission page, the process is straightforward. Enter your first and last names, provide some location and contact details and away you go. This will also apparently earn you "frequent flyer points" to "allow you to send your name on future Journey to Mars launches".
While cool, the opportunity isn't particularly unique — according to the submission website, over 996,970 people already have their passes sorted. That's awesome in its own way though... at the very least we can feel sorry for the poor NASA intern stuck with printing nearly a million of the things.
This is why NASA needs a bigger budget people! Ink and paper!