VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, NASA's Orbiting Carbon Observatory, or OCO, atop Orbital Sciences' Taurus XL rocket has been erected for launch. Around the spacecraft's fairing, at top, is the non-flight environmental shield that will be removed before launch. OCO is scheduled for launch the Taurus 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 courtesy of Brett Gladish, Orbital SciencesThe two spacecraft will be integrated with the Atlas V and tested for final flight worthiness. Launch is scheduled for the spring. LCROSS and LRO are the first missions in NASA's plan to return humans to the moon and begin establishing a lunar outp