ABOARD THE INTERNATIONAL SPACE STATION -- 29 May 2011 -- The International Space Station is featured in this image photographed by an STS-134 crew member on the space shuttle Endeavour

ABOARD THE INTERNATIONAL SPACE STATION -- 29 May 2011 -- The International Space Station is featured in this image photographed by an STS-134 crew member on the space shuttle Endeavour after the station and shuttle began their post-undocking relative separation. Undocking of the two spacecraft occurred at 11:55 p.m. (EDT) on May 29, 2011. Endeavour spent 11 days, 17 hours and 41 minutes attached to the orbiting laboratory -- Picture by Lightroom Photos/NASA