SICILY, ITALY - OCTOBER 30: (FILE IMAGE) This image, taken from cameras onboard the International Space Station, shows plumes of smoke and ash erupting from Mount Etna on October 30, 2002 in Sicily, Italy. The image looks as if it were taken by a high altitude aircraft, but in fact it was taken with a high magnification lens from space. (Photo by ISS/NASA/Getty Images)
1991: View from the Space Shuttle Columbia looking Northwest over the Gulf of Oman (bottom), the Strait of Hormuz (centre) and the Arabian Gulf (top). Corbis
1999: Clouds and the sun seen during the STS-96 mission from the Space Shuttle Discovery.
1992: Rick Hieb, a Mission Specialist aboard STS-49, looks into the aft flight deck of the orbiter during his spacewalk. It was the first flight of Endeavour and the first shuttle mission to help to recover a communications satellite whose orbit had becom???
May 16 2010: The Space Shuttle Atlantis is pictured against the Earth prior to docking with the International Space Station. Reuters/NASA
March 7 2011: The International Space Station is featured in this image photographed by an STS-133 crew member on space shuttle Discovery after the station and shuttle began their post-undocking relative separation. AP Photo/NASA
March 6 2011: The Earth's thin line of atmosphere and a gibbous moon photographed by an Expedition 26 crew member on the International Space Station. AP Photo/NASA
May 12 2009: The Space Shuttle Atlantis silhouetted against the sun. AP Photo/NASA
Astronaut Dale A. Gardner holds up a "For Sale" sign referring to the two satellites, Palapa B-2 and Westar 6 that were retrieved from orbit by the Discovery crew. A portion of each of two recovered satellites is in the lower right corner, with Westar 6 ???
1996: View of the Remote Manipulator System (RMS) end effector over an Earth limb with a solar starburst pattern behind it. Courtesy NASA