VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, cranes wait in the early morning hours for winds to subside in order to lift the tent that covers NASA's Orbiting Carbon Observatory, or OCO, the Taurus XL upper stack and the umbilical tower. 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