Let's see....you'll be 18 in 2013....you'll need a degree in something science-based, which will take you to 2016, but...
...the Orion is a NASA spacecraft, and to be a NASA astronaut, you have to have US nationality.
Perhaps you could do your degree in America and gain nationality that way? However, you should check how long you need to live in America for before you can apply.
Have a look at this link for more info:
http://hubpages.com/hub/the_difference_between_stars_and_planets
Good luck little man and hope you see the stars closeup some day!!