
Space Shuttle Endeavour is ferried by NASA's Shuttle Carrier Aircraft (SCA) over Houston, Texas on September 19, 2012. NASA pilots…

NASA's Shuttle Carrier Aircraft with the space shuttle Endeavour securely mounted on top makes a low-level flyby of the flight…

NASA's Shuttle Carrier Aircraft with the space shuttle Endeavour securely mounted on top touches down at Edwards Air Force Base.

NASA's Shuttle Carrier Aircraft with the space shuttle Endeavour securely mounted on top touches down at Edwards Air Force Base.

NASA's Shuttle Carrier Aircraft with the space shuttle Endeavour securely mounted on top touches down at Edwards Air Force Base.

NASA's Shuttle Carrier Aircraft with the space shuttle Endeavour securely mounted on top touches down at Edwards Air Force Base.

NASA's Shuttle Carrier Aircraft with the space shuttle Endeavour securely mounted on top touches down at Edwards Air Force Base.

This map from NASA's Dawn mission shows the global distribution of hydrogen on the surface of the giant asteroid Vesta.…

These enhanced-color views from NASA's Dawn mission show an unusual "pitted terrain" on the floors of the craters named Marcia…

This perspective view of Marcia crater on the giant asteroid Vesta shows the most spectacularly preserved example of "pitted terrain,"…