Colonel Hansen was one of two recruits selected by the Canadian Space Agency (CSA) in May 2009 through the third Canadian Astronaut Recruitment Campaign. He is one of 14 members of the 20th National Aeronautics and Space Administration (NASA) astronaut class. In 2011, Colonel Hansen graduated from Astronaut Candidate Training, which included scientific and technical briefings, intensive instruction in International Space Station (ISS) systems, extravehicular activities (EVAs, or spacewalks), robotics, physiological training, T-38 flight training, Russian language courses, and sea and wilderness survival training.
While waiting for a flight assignment, Colonel Hansen represents CSA at NASA, and works at the Mission Control Center as Capcom — the voice between the ground and the ISS.
In addition to his day-to-day work, Colonel Hansen remains committed to building and maintaining his skills; he takes spacewalk and robotics training while continuing to learn Russian. He has taken part in geological expeditions in the High Arctic and participated in the European Space Agency's CAVES program, during which he lived underground for six days. He was also a crew member for NEEMO 19, where he lived and worked on the ocean floor in the Aquarius habitat off Key Largo, Florida, for seven days simulating deep space exploration. Colonel Hansen also continues to fly the CF-18 fighter jet with the Royal Canadian Air Force and had the privilege of inspiring young Canadians by flying the historical Hawk One F-86 Sabre jet.