Franklin Ramón Chang-Díaz (born April 5, 1950) is a Costa Rican-born American mechanical engineer, physicist, and former NASA astronaut. He is the sole founder and CEO of Ad Astra Rocket Company as well as a member of Cummins' board of directors. He became an American citizen in 1977.

He is a veteran of seven Space Shuttle missions, tying the record, as of 2021 for the most spaceflights (a record set by Jerry L. Ross). He was the third Latin American, but the first Latin American immigrant NASA Astronaut selected to go into space. Chang-Díaz is a member of the NASA Astronaut Hall of Fame.

Franklin Ramón Chang-Díaz was born in San José, Costa Rica on April 5, 1950, to Ramón Ángel Chang Morales, an oil worker whose own father fled China during the Boxer Rebellion, and María Eugenia Díaz Romerois. One of six children, he has a younger sister, Sonia Rosa (born December 1952) and his mother, brothers and sisters still reside in Costa Rica. His two eldest daughters with his ex-wife Candice Chang, include Sonia Rosa, who is a member of the Massachusetts Senate. He married in the United States, on December 17, 1984, Dr. Peggy Marguerite Doncaster (née Stafford, of Alexandria, Louisiana), with whom he has two daughters, both born in Houston, Texas.

He graduated from Colegio de La Salle in San Jose with an “A” in November 1967, then moved to the United States to finish his high school education at Hartford Public High School in Connecticut, in 1969. He went on to attend the University of Connecticut, where he earned a B.S. degree in mechanical engineering and joined the federal TRIO Student Support Services program in 1973. He then attended the Massachusetts Institute of Technology (MIT), where he earned a Ph.D. degree in applied plasma physics in 1977. For his graduate research at Massachusetts Institute of Technology (MIT), Chang-Díaz worked in the field of fusion technology and plasma-based rocket propulsion.

Chang-Díaz was selected as an astronaut candidate by NASA in 1980 and first flew aboard Space Shuttle mission STS-61-C in 1986. Subsequent missions included STS-34 (1989), STS-46 (1992), STS-60 (1994), STS-75 (1996), STS-91 (1998), and STS-111 (2002). During STS-111, he performed three extravehicular activities (EVAs) with Philippe Perrin as part of the construction of the International Space Station (ISS). He was also director of the Advanced Space Propulsion Laboratory at the Johnson Space Center from 1993 to 2005. Chang-Díaz retired from NASA in 2005.

After leaving NASA, Chang-Díaz set up the Ad Astra Rocket Company, which became dedicated to the development of advanced plasma rocket propulsion technology. Years of research and development have produced the Variable Specific Impulse Magnetoplasma Rocket (VASIMR), an electrical propulsion device for use in space. With a flexible mode of operation, the rocket can achieve very high exhaust speeds, and with a sufficiently powerful electrical supply even has the theoretical capability to take a crewed rocket to Mars in 39 days.

Chang-Díaz also is active in environmental protection and raising awareness about climate change, notably in his role in Odyssey 2050 The Movie in which he encourages young people to get motivated about environmental issues.

In addition, Chang-Díaz is an Adjunct Professor in Physics and Astronomy at Rice University. He has been on the board of directors of Cummins since December 8, 2009.

He is also the father of Democratic candidate for the 2022 Massachusetts gubernatorial election Sonia Chang-Díaz.

Source: https://en.wikipedia.org/wiki/Franklin_Chang-D%C3%ADaz