In 1960 Jim got an invitation to go through testing to become one of the first astronaut pilots. Many men were chosen to undergo extensive medical and psychological tests; only six made it. This was uncharted territory - there were literally no guidelines or precedents on how to become an astronaut .

As a matter of fact, these men tended to be more concerned with the careers they were giving up rather than the career they would gain. Due to a medical technicality, Jim didn't make the first cut. However, as the NASA program continued there was a need for more astronauts. When Jim tried out a second time, he passed NASA's selection criteria.

Two years later on September 13, 1962 Jim got a call from Deke Slayton inviting him to join the new astronaut team. Once at NASA he underwent extensive training and learned the basics of space flight . Thus, in1963, his career began as an astronaut during the Gemini Program.