The main landing gear on the space shuttle Atlantis touches down to mark mission completion at Edwards Air Force Base.

The main landing gear on the space shuttle Atlantis touches down to mark mission completion at Edwards Air Force Base in the Mojave Desert of California.Onboard were astronauts Kenneth Cockrell, Mark Polansky, Robert Curbeam, Thomas Jones and Marsha Ivins. Atlantis touched down on Edward?s concrete runway at 2:33 p.m. (CST), Feb. 20, for a mission elapsed time of 12 days, 21 hours and 20 minutes. Photo credit: NASA