NASA - National Aeronautics and Space Administration

S134-E-010904 (30 May 2011) --- NASA astronaut Greg Chamitoff, STS-134 mission specialist, reads a procedures checklist while working on the aft flight deck of space shuttle Endeavour during flight day 15 activities. Photo credit: NASA

S134-E-010905 (30 May 2011) --- European Space Agency astronaut Roberto Vittori (left) and NASA astronaut Greg Chamitoff, both STS-134 mission specialists, are pictured on the aft flight deck of space shuttle Endeavour during flight day 15 activities. Photo credit: NASA

S134-E-010911 (30 May 2011) --- STS-134 crew members are busy on the aft flight deck of space shuttle Endeavour during undocking and fly-around operations with the International Space Station on flight day 15. Pictured are NASA astronauts Mark Kelly (right), commander; and Greg H. Johnson (left), pilot; along with European Space Agency astronaut Roberto Vittori (second left), NASA astronauts Andrew Feustel (bottom) and Greg Chamitoff, all mission specialists. Photo credit: NASA

S134-E-010931 (30 May 2011) --- NASA astronauts Greg H. Johnson (left), STS-134 pilot; Michael Fincke (center) and Greg Chamitoff, both mission specialists, are busy on the aft flight deck of space shuttle Endeavour during undocking and fly-around operations with the International Space Station on flight day 15. Chamitoff is using a handheld laser ranging device -- designed to measure the range between two spacecraft -- through one of the overhead windows. Photo credit: NASA

S134-E-010933 (30 May 2011) --- NASA astronauts Greg H. Johnson (left), STS-134 pilot; Michael Fincke (center) and Greg Chamitoff, both mission specialists, are busy on the aft flight deck of space shuttle Endeavour during undocking and fly-around operations with the International Space Station on flight day 15. Chamitoff is using a handheld laser ranging device -- designed to measure the range between two spacecraft -- through one of the overhead windows. Photo credit: NASA

S134-E-010934 (30 May 2011) --- NASA astronauts Greg H. Johnson (left), STS-134 pilot; Michael Fincke (center) and Greg Chamitoff, both mission specialists, are busy on the aft flight deck of space shuttle Endeavour during undocking and fly-around operations with the International Space Station on flight day 15. Chamitoff is using a handheld laser ranging device -- designed to measure the range between two spacecraft -- through one of the overhead windows. Photo credit: NASA

S134-E-010935 (30 May 2011) --- NASA astronauts Greg H. Johnson (left), STS-134 pilot; Michael Fincke (center) and Greg Chamitoff, both mission specialists, are busy on the aft flight deck of space shuttle Endeavour during undocking and fly-around operations with the International Space Station on flight day 15. Chamitoff is using a handheld laser ranging device -- designed to measure the range between two spacecraft -- through one of the overhead windows. Photo credit: NASA

S134-E-010950 (30 May 2011) --- NASA astronaut Mark Kelly, STS-134 commander, is pictured on the flight deck of space shuttle Endeavour during undocking and fly-around operations with the International Space Station on flight day 15. Photo credit: NASA

S134-E-010959 (30 May 2011) --- NASA astronaut Greg H. Johnson, STS-134 pilot, is pictured near an overhead window on the aft flight deck of space shuttle Endeavour after undocking with the International Space Station (visible through the window) on flight day 15. Photo credit: NASA

S134-E-010973 (30 May 2011) --- NASA astronaut Mark Kelly (left), STS-134 commander; and European Space Agency astronaut Roberto Vittori, mission specialist, are pictured on the forward flight deck of space shuttle Endeavour during undocking and fly-around operations with the International Space Station on flight day 15. Photo credit: NASA