On Launch Complex 576-E at Vandenberg Air Force Base stack is lowered onto the Stage 0 motor of the Taurus XL vehicle.

On Launch Complex 576-E at Vandenberg Air Force Base in California, NASA's Orbiting Carbon Observatory, OCO, upper stack is lowered onto the Stage 0 motor of the Taurus XL vehicle. The upper stack consists of Stages 1, 2 and 3 of the Taurus, as well as the encapsulated OCO spacecraft. 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