He has made four space flights and has performed seven space walks totalling 49 hours, the second-highest number of space walk hours in NASA history. Two space walks occurred during the April 2002 flight of Atlantis to the International Space Station (ISS) when a truss was installed. Smith joined NASA in 1989 as a payload officer and was selected as an astronaut in 1992. He is currently NASA's manager of the Automated Transfer Vehicle (ATV) Launch Package for the ISS.