On Launch Complex 576-E at Vandenberg Air Force Base in California, NASA's Orbiting Carbon Observatory, OCO, upper stack is lifted high for transfer to the waiting Stage 0 motor of the Taurus XL vehicle at left. The upper stack consists of Stages 1, 2 and 3 of the Taurus. The spacecraft is scheduled for launch aboard Orbital Sciences' Taurus XL rocket Feb. 24 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. Photo credit: NASA/Randy Beaudoin, VAFB