Christina Marie Birch (born November 17, 1986) is an American professional racing cyclist and NASA astronaut.

While at MIT she won the 2014 USA Cycling collegiate cyclocross division two national championship.

[1] After earning a doctorate in biological engineering from MIT in 2015, Birch moved to Southern California to pursue track cycling full time.

She competed at the 2018 and 2019 UCI Track Cycling World Championships, and the 2019 Pan American Games.

[2] Birch was named to the US track cycling 2020 Olympics long team for the USA in June 2020.