Franklin Ramón Chang Díaz (born April 5, 1950) is a Costa Rican-American mechanical engineer, physicist and former NASA astronaut. He became an American citizen in 1977. He is of Chinese (paternal grandfather) and Costa Rican Spanish (maternal side) descent. Chang Díaz is currently president and CEO of Ad Astra Rocket Company. He is a veteran of seven Space Shuttle missions, making him the record holder as of 2014 for the most spaceflights (a record he shares with Jerry L. Ross). He was the third Latin American to go into space. Chang Díaz is a member of the NASA Astronaut Hall of Fame.