Quantcast
Last updated on April 17, 2014 at 12:34 EDT
431 of 1107

August 13, 2012
A bank of video screens shows the progress of a simulated spacewalk as the crew of STS-135 trains in the Neutral Buoyancy Laboratory near NASA's Johnson Space Center in Houston March 10, 2011. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool