Franklin Ramón Chang Díaz (born April 5, 1950, in San José, Costa Rica) is a pioneering Costa Rican–American mechanical engineer, physicist, and former NASA astronaut. After immigrating to the U.S. in 1968 on just $50 and no English, he graduated from Hartford High School (1969), earned a B.S. in mechanical engineering from the University of Connecticut (1973), and a Ph.D. in applied plasma physics from MIT (1977). Selected by NASA in 1980 as part of Astronaut Group 9, he flew on a record-setting seven Space Shuttle missions between 1986 and 2002 (STS‑61C, ‑34, ‑46, ‑60, ‑75, ‑91, ‑111), logging over 1,600 hours in space and nearly 20 hours of EVA, deploying Galileo, contributing to Shuttle‑Mir collaboration, and helping construct the ISS. As a scientist-astronaut, he led NASA’s Advanced Space Propulsion Laboratory (1993–2005) and conceived the VASIMR plasma rocket, founding Ad Astra Rocket Company in 2005 to develop it for future deep-space missions. Among his many honors are NASA’s Distinguished Service and Space Flight Medals, the 1986 Liberty Medal, induction into the U.S. Astronaut Hall of Fame (2012), and several honorary doctorates. Courtesy of NASA.