NASA astronauts Alvin Drew Michael Barratt and Nicole Stott are pictured in the Unity node of the International Space Station.

NASA astronauts Alvin Drew (left), Michael Barratt and Nicole Stott, all STS-133 mission specialists, are pictured in the Unity node of the International Space Station while space shuttle Discovery remains docked with the station. Photo credit: NASA or National Aeronautics and Space Administration