VANDENBERG AIR FORCE BASE, Calif. -- - Workers check the movement of the fairing at right toward NASA's Orbiting Carbon Observatory, or OCO, at left, to complete installation. The work is being done in Building 1032 of 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 th