Franklin Ramon Chang-Díaz (born April 5, 1950, San José, Costa Rica)[1] is an American mechanical engineer, physicist, and former NASA astronaut.

He is the sole founder and CEO of Ad Astra Rocket Company[2] as well as a member of the Cummins' board of directors.

[7] His two eldest daughters with his ex-wife Candice Chang, include Sonia Rosa, who is a member of the Massachusetts Senate.

During STS-111, he performed three extravehicular activities (EVAs) with Philippe Perrin as part of the construction of the International Space Station (ISS).

Years of research and development have produced the Variable Specific Impulse Magnetoplasma Rocket (VASIMR), an electrical propulsion device for use in space.

He was inducted into the NASA Astronaut Hall of Fame on May 5, 2012[22] in a ceremony that took place in the Kennedy Space Center Visitor Complex.

Also, due to his career and scientific success, he has been decorated multiple times in Costa Rica and named Honor Citizen by the national legislature.