Eleven-time American national champion Christina Birch is swapping the cycling velodrome to start a journey she hopes will take her all the way to the moon. Birch’s drastic change of direction comes after being selected for the NASA Astronaut Class of 2021, which will see her embark on a two-year training course for the Artemis missions in Houston, Texas. “I am super excited to be a 2021 Astronaut Candidate. It is a little still surreal for me,” Birch, a two-time Pan-American champion, said in a statement from USA Cycling. “It wasn’t probably until I put on the blue flight suit for the first time that it actually started to feel real.” Birch was on the long list for the Tokyo Olympics and submitted her application while preparing at the Olympic Training Center in Colorado Springs. “I filled out my application online before we headed back to the track for some …