VANDENBERG AIR FORCE BASE, Calif. -- The Stage 1, 2 and 3 motors of the Taurus XL rocket are being prepared for transfer to Space Launch Complex 576-E at Vandenberg Air Force Base in California. The Taurus is the launch vehicle for NASA's Orbiting Carbon Observatory, or OCO, which is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The observatory is scheduled to launch Feb. 23 from Vandenberg. The spacecraft will collect precise global measurements of carbon dioxide (CO2) in the Earth's atmosphere. Scientists will analyze OCO data to improve our understanding of the natural processes and human activities that regulate the abundance and distribution of this important greenhouse gas. This improved understanding will enable more reliable forecasts of future changes in the abundance and distribution of CO2 in the atmosphere and the effect that these changes may have on the Earth's climate. Photo credit: NASA/Randy Beaudoin, VAFB KSC-2009-1559