S133-E-008319 (3 March 2011) --- NASA astronaut Michael Barratt (foreground), STS-133 mission specialist; and Scott Kelly, Expedition 26 commander, perform maintenance on the Carbon Dioxide Removal Assembly (CDRA) in the Air Revitalization 2 (AR2) rack in the Tranquility node of the International Space Station while space shuttle Discovery remains docked with the station. Photo credit: NASA or National Aeronautics and Space Administration
Date March 3, 2011