With a combination of luck, skill and elbow grease, trainees that pass the rigorous program are selected as NASA astronaut candidates and then go on to graduate from the basic training process.
OK, so what happens then? Well, most won't actually be eligible to go up into space until the administration assigns them to their first mission. Then, they have to complete even more specialized training to prepare themselves for the journey. A rookie space traveler will generally embark upon his or her maiden voyage with a couple of veteran astronauts who double as his or her advisers [source: NASA].
Recent graduates of the basic training process may not receive their first mission assignment for a couple of years. During this so-called pre-assignment phase, most astronauts perform Earth-bound jobs like collaborating with their space program's engineers or serving as foreign liaisons. Dottie Metcalf-Lindenburger finished her general NASA training in 2006 but didn't venture into Earth's orbit until 2010. For those now going through a pre-assignment period, she recommends finding time to refresh your astronaut skill set [source: Metcalf-Lindenburger].
Over at the ESA, Swedish astronaut Christer Fuglesang spent 14 years in limbo before he was finally put on his first mission. On the other hand, Luca Parmitano of Italy managed to secure an assignment from the agency before he'd even finished basic training [source: Peake].