He flew with the space shuttle Endeavour in January 1996, when he undertook a six-hour space walk to evaluate techniques to be used to assemble the International Space Station (ISS). He was also aboard the space shuttle Discovery, launched in May 1999 to deliver supplies to the ISS before the arrival of the first resident crew, and on the Discovery flight in August 2001 to the ISS to exchange crews and to attach the Leonardo module. Barry was selected as an astronaut in 1992. He retired from NASA in April 2005 to start his own company, Denbar Robotics, where he currently builds robots.