Dafydd Rhys "Dave" Williams OC (born May 16, 1954) is a Canadian physician, public speaker and a retired CSA astronaut. Williams was a mission specialist on two space shuttle missions. His first spaceflight, STS-90 in 1998, was a 16-day mission aboard Space Shuttle Columbia dedicated to neuroscience research. His second flight, STS-118 in August 2007, was flown by Space Shuttle Endeavour to the International Space Station. During that mission he performed three spacewalks, becoming the third Canadian to perform a spacewalk and setting a Canadian record for total number of spacewalks. These spacewalks combined for a total duration of 17 hours and 47 minutes.
STS-90 was a 1998 Space Shuttle mission flown by the Space Shuttle Columbia. The 16-day mission marked the last flight of the European Space Agency's Spacelab laboratory module, which had first flown on Columbia on STS-9, and was also the last daytime landing for Columbia.Low Earth Orbit
The Canadian Space Agency was established by the Canadian Space Agency Act which received Royal Assent on May 10, 1990. The Canadian space program is administered by the Canadian Space Agency. Canada has contributed technology, expertise and personnel to the world space effort, especially in collaboration with ESA and NASA. In addition to its astronauts and satellites, some of the most notable Canadian technological contributions to space exploration include the Canadarm on the Space Shuttle and Canadarm2 on the International Space Station.