Dafydd Williams

Dafydd Rhys Williams (born May 16, 1954) is a Canadian physician, public speaker, writer and retired astronaut. He was chosen by the Canadian Space Agency (CSA) in 1992. Williams took part in two spaceflights. He flew aboard Space Shuttle "Columbia" for mission STS-90 and Space Shuttle "Endeavour" for mission STS-118.
In 1998, Williams became the first non-American to hold a senior management position within NASA. He held the role of Director of the Space and Life Sciences Directorate at the Johnson Space Center and Deputy Associate Administrator of the Office of Spaceflight at NASA's headquarters.
Williams was born in Saskatoon, Saskatchewan. His father, Bill Williams, was Welsh. He is married and has three children. In 2004, he had his prostate removed after he was diagnosed with cancer.