Dave Williams | The Canadian Encyclopedia


Dave Williams

Dafydd (Dave) Rhys Williams, OC, OOnt, astronaut, aquanaut, scientist, pilot, physician, author (born 16 May 1954 in Saskatoon, SK). Dr. Dave Williams was a mission specialist on two NASA space shuttle missions and an aquanaut participating in undersea research. As a medical doctor and an astronaut, he contributed to vital life-science experiments focused on the effects of microgravity on the human brain and nervous system. (See also Canadian Space Agency.) He has served as a senior administrative officer at numerous medical institutions.

Dave Williams at the Saskatchewan Science Centre in Regina, 20 July 2019

Early Life and Education

When Dave Williams was a child, his family moved to Beaconsfield, Quebec, where he attended school. He became interested in space exploration while watching televised launches from Cape Canaveral, Florida. As a boy, he took scuba diving instruction and earned his certificate. He also received Royal Canadian Army cadet training.

For his postsecondary education, Williams enrolled at McGill University and, in 1976, received a bachelor of science degree, with a major in biology. He later took flying instruction, earned commercial and multi-engine licences and trained in aerobatics. In 1983, he earned a master of science in physiology, as well as a doctorate of medicine and a master of surgery from the faculty of medicine at McGill University. In 1985, he completed a residency in family practice from the faculty of medicine at the University of Ottawa. In 1988, after completing a residency in emergency medicine at the University of Toronto, Williams received a fellowship in emergency medicine from the Royal College of Physicians and Surgeons of Canada.

Medical Career

Dave Williams undertook postgraduate studies at the University of Washington in Seattle. During this period, his interests shifted from invertebrate physiology to vertebrate neurophysiology. Research for his master’s thesis research involved the study of steroid hormones and the regulation of sleep-wake cycles. He assisted in clinical studies at the Allan Memorial Institute in Montreal.

In 1988, he became an emergency physician with the department of emergency services at Sunnybrook Health Sciences Centre in Toronto and a lecturer in the department of surgery at the University of Toronto. He was a member of the Air Ambulance Utilization Committee with the Ontario Ministry of Health as an academic emergency physician and a representative of community emergency physicians. From 1989 to 1990, Williams was an emergency physician with the Emergency Associates of Kitchener-Waterloo and medical director of Kitchener’s Westmount Urgent Care Clinic. Williams returned to Sunnybrook in 1990 as medical director of the Advanced Cardiac Life Support (ACLS) program and coordinator of postgraduate training in emergency medicine. Then he became director of the department of emergency services at Sunnybrook and assistant professor of surgery and medicine at the University of Toronto.

Astronaut and Aquanaut

Canadian astronaut team, 1992

Dave Williams applied to the Canadian Space Agency (CSA) at the suggestion of his wife, flying instructor and Air Canada pilot Cathy Williams (née Fraser). He was informed in June 1992 that he, along with three others Julie Payette, Chris Hadfield and Robert Stewart (later replaced by Mike McKay), had been selected from a field of 5,330 applicants (see Canadian Astronauts). He completed basic training and, in May 1993, was appointed manager of the Missions and Space Medicine Group within the CSA Canadian Astronaut Program. His work included supervising the implementation of operational space-medicine activities for the Canadian Astronaut Program Space Unit Life Simulation (CAPSULS) Project. During the seven-day simulated space mission in February 1994, Williams was the principal investigator of a study evaluating the initial training and retention of CPR skills by non-medical astronauts. He also served as the crew’s medical officer.

Williams was chosen to join the international class of NASA mission specialist astronaut candidates in January 1995. In March 1995, he reported to NASA’s Johnson Space Center (JSC) in Houston, Texas, for training and evaluation. On completion of basic training in May 1996, Williams was assigned to the Payloads and Habitability Branch of NASA’s Astronaut Office. In April 1998, on the STS-90 mission, Williams was one of the seven-person crew aboard the space shuttle Columbia. He was a mission specialist during the 16-day space flight, orbiting the Earth 256 times and travelling 10 million kilometres (more than 6.2 million miles). Williams served as a medical officer, an extravehicular activity (EVA) crew member and a flight engineer during the ascent phase. He assisted in performing 26 experiments that focused on the effects of microgravity on the brain and nervous system.

Did you know?
From July 1998 to September 2002, he served as director of the space and life sciences directorate at NASA’s Johnson Space Center in Houston, Texas, making him the first non-American to hold a senior management position within NASA.

In 2001, Williams became the first Canadian to have lived and worked in both space and the ocean when he served as an aquanaut with the National Oceanic and Atmospheric Administration (NOAA) NASA Extreme Environment Mission Operations (NEEMO) mission. He spent seven days training off the coast of Florida in Aquarius, an underwater research laboratory. In 2006, he was crew commander of the 18-day NEEMO 9 mission.

In 2007, from 8 to 21 August, Williams participated in the STS-118 mission. He travelled on the space shuttle Endeavour to the International Space Station (ISS). As a member of the ISS crew, he did structural work on the station and participated in three spacewalks, serving as a leader for two of them.

Photograph of Dave Williams performing a spacewalk during the STS-118 mission, 13 August 2007.

Later Career

Dave Williams retired from astronaut service in March 2008. He continued his medical career in Hamilton, Ontario, as chief medical officer of patient safety and quality at St. Joseph’s Healthcare Hamilton and as a professor in the department of surgery at the Michael G. DeGroote School of Medicine at McMaster University, where he was also director of the McMaster Centre for Medical Robotics. In July 2011, he became president and CEO of the Southlake Regional Health Centre in Newmarket, Ontario. He has often been called upon as a speaker on topics such as health care and technology, environmental stewardship, risk management and motivation.


In 2010, a McMaster University graduate scholarship was named after Dave Williams. Similarly, a public school in Oakville, Ontario, was named in his honour.


Dave Williams is the author of Defying Limits: Lessons from the Edge of the Universe (2019), an autobiographical book and several space-related non-fiction books for juvenile readers.

Honours and Awards

  • NASA Space Flight Medal, NASA (1998)
  • Bronze Medal for contribution to neuroscience during Mission STS-90, Spanish Council for Scientific Research (1999)
  • NASA Outstanding Leadership Medal, NASA (2002)
  • NASA Johnson Space Center (JSC) Space and Life Science Directorate Special Professional Achievement Award, NASA (2003)
  • Honorary Doctor of Laws, University of Saskatchewan (2004)
  • Honorary Doctor of Science, McGill University (2007)
  • Inductee, Canada’s Aviation Hall of Fame (2012)
  • Officer, Order of Canada (2014)
  • Honorary Doctor of Laws, Dalhousie University (2016)
  • Order of Ontario (2020)
  • Honorary Doctor of Science, Carleton University (2022)

Further Reading

External Links

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