Serving as a space shuttle pilot, he flew on Columbia during its mission in July 1999 to deploy the Chandra X-Ray Observatory, on the Endeavour flight in April 2001 to the International Space Station (ISS) to deliver and install the Canadarm and resupply the logistics module Raffaello, and on the Atlantis flight in 2002 to the ISS to install the Integrated Truss Segment. He has logged 660 hours in space and 436 orbits. Ashby was selected as an astronaut in 1994. Ashby left NASA in June 2008 to work for Blue Origins as chief of mission assurance.