Thirsk, Robert Brent (1953- )

Canadian astronaut and physician. He flew with the Columbia space shuttle mission in June 1996 that carried out 43 experiments in life and materials sciences. Thirsk was selected in 1983 as a Canadian astronaut and led an international research team to study the effect of weightlessness on the heart and blood vessels. He also headed a programme to design and test an antigravity spacesuit. Thirsk was assigned to NASA's Johnson Space Center in 1998 to train as a mission specialist and went on to become a CapCom (spacecraft communicator) for the International Space Station.