Donald Alan Thomas

Donald Alan Thomas, Ph.D. (born May 6, 1955) is an American engineer and a former NASA astronaut.

Selected by NASA in January 1990, Dr. Thomas became an astronaut in July 1991. A veteran of four space flights, he logged over 1,040 hours in space. He was a mission specialist on STS-65 (July 8, 1994 – July 23, 1994), STS-70 (July 13, 1995 – July 22, 1995), STS-83 (April 4, 1997 – April 8, 1997) and STS-94 (July 1, 1997 – July 17, 1997). Initially assigned to the ISS Expedition 6 crew, his flight assignment withdrawal resulted from a medical issue affecting long duration space flight qualifications.

In his last assignment he served as the International Space Station Program Scientist overseeing NASA experiments performed on the ISS.