The bucket truck into position over the fairing access door on NASA's Orbiting Carbon Observatory or OCO.

On Launch Complex 576-E at Vandenberg Air Force Base in California, Orbital Sciences Engineer Jose Castillo maneuvers the bucket truck into position over the fairing access door on NASA's Orbiting Carbon Observatory, or OCO. On the top of the OCO fairing is the shadow of Glenn Weigle of Orbital Satellite Systems Group, on the bucket at upper left, who is prepared to move in and inspect the GN2 instrument purge flow. OCO 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/Richard Nielsen, KSC