Shuttle Discovery's final spacewalk
Two American astronauts have completed the last shuttle Discovery spacewalk before the craft is retired from service.
Steve Bowen and Alvin Drew spent six hours on Wednesday completing chores outside the International Space Station as the 30-year U.S. shuttle program nears an end later this year.
Discovery undocks from the space station Sunday for the two-day journey home.
First launched in 1984, this is Discovery's 39th and final space mission.
03 Mar 2011