Science / International Space Station Fifth Spacewalk Completes Shuttle Crew's To-Do List Endeavour crew successfully completes maintenance and upgrades of space station By Nick McMaster, Newser Staff Posted Jul 27, 2009 2:07 PM CDT Copied Astronauts Tom Marshburn and Christopher Cassidy mission specialists for STS-127, share duties on the fourth spacewalk of Endeavour's current mission, July 24, 2009. (AP Photo) Astronauts from the space shuttle Endeavour today completed the final tasks of their mission to upgrade and maintain the International Space Station’s Kibo lab, Space.com reports. Crewmen Chris Cassidy and Tom Marshburn spent five hours in space rewiring the station’s altitude control system and adding some TV cameras to the experiment porch addition to Kibo. Including today’s fifth spacewalk, Endeavour’s crew spent 30½ hours during their 16-day mission working in space. The shuttle will undock from the station tomorrow and is scheduled to return to Earth on Friday. (More International Space Station stories.) Report an error