VANDENBERG AIR FORCE BASE, Calif. -- The first half of the fairing is placed around NASA's Orbiting Carbon Observatory, or OCO, at Vandenberg Air Force Base in California. The fairing is a molded structure that fits flush with the outside surface of the rocket and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent. The spacecraft is scheduled for launch aboard Orbital Sciences' Taurus XL rocket on Feb. 23 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. This improved understanding will enable more reliable forecasts of future changes in the abundance and distribution of CO2 in the atmosphere and the effect that these changes may have on the Earth's climate.