VANDENBERG AIR FORCE BASE, Calif. -- At Vandenberg Air Force Base in California, the transporter holding NASA's Orbiting Carbon Observatory, or OCO, heads for Launch Complex 576-E. 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. OCO is scheduled to launch Feb. 24 aboard an Orbital Sciences' Taurus XL rocket. Photo credit: NASA/VAFB

VANDENBERG AIR FORCE BASE, Calif. -- At Vandenberg Air Force Base in California, the transporter holding NASA's Orbiting Carbon Observatory, or OCO, arrives on Launch Complex 576-E. 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. OCO is scheduled to launch Feb. 24 aboard an Orbital Sciences' Taurus XL rocket. Photo credit: NASA/VAFB

VANDENBERG AIR FORCE BASE, Calif. -- At Vandenberg Air Force Base in California, the transporter holding NASA's Orbiting Carbon Observatory, or OCO, heads for Launch Complex 576-E. 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. OCO is scheduled to launch Feb. 24 aboard an Orbital Sciences' Taurus XL rocket. Photo credit: NASA/VAFB

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, NASA's Orbiting Carbon Observatory, or OCO, has been erected atop Orbital Sciences' Taurus XL rocket for a Feb. 24 launch. 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/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, NASA's Orbiting Carbon Observatory, or OCO, has been erected atop Orbital Sciences' Taurus XL rocket for a Feb. 24 launch. 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/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- In the Astrotech payload processing facility at Vandenberg Air Force Base in California, NASA's Orbiting Carbon Observatory, or OCO, is being prepared for transfer to Launch Complex 576-E. 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. OCO is scheduled to launch Feb. 24 aboard an Orbital Sciences' Taurus XL rocket. Photo credit: NASA/VAFB

VANDENBERG AIR FORCE BASE, Calif. -- In the Astrotech payload processing facility at Vandenberg Air Force Base in California, workers secure an overhead crane to NASA's Orbiting Carbon Observatory, or OCO. The spacecraft will be moved to a transporter for the trip to Launch Complex 576-E. An umbilical line (left) has been attached. 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. OCO is scheduled to launch Feb. 24 aboard an Orbital Sciences' Taurus XL rocket. Photo credit: NASA/VAFB

VANDENBERG AIR FORCE BASE, Calif. -- At Vandenberg Air Force Base in California, the transporter holding NASA's Orbiting Carbon Observatory, or OCO, is ready to leave the Astrotech payload processing facility for Launch Complex 576-E. An umbilical line is attached. 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. OCO is scheduled to launch Feb. 24 aboard an Orbital Sciences' Taurus XL rocket. Photo credit: NASA/VAFB

VANDENBERG AIR FORCE BASE, Calif. -- In the Astrotech payload processing facility at Vandenberg Air Force Base in California, workers keep watch as a crane lifts and moves NASA's Orbiting Carbon Observatory, or OCO, to a transporter (foreground). 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. OCO is scheduled to launch Feb. 24 aboard an Orbital Sciences' Taurus XL rocket. Photo credit: NASA/VAFB

VANDENBERG AIR FORCE BASE, Calif. -- In the Astrotech payload processing facility at Vandenberg Air Force Base in California, workers help guide NASA's Orbiting Carbon Observatory, or OCO, into place on a transporter. The spacecraft will be moved to Launch Complex 576-E. An umbilical line is attached. 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. OCO is scheduled to launch Feb. 24 aboard an Orbital Sciences' Taurus XL rocket. Photo credit: NASA/VAFB

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, NASA's Orbiting Carbon Observatory, or OCO, spacecraft awaits a GN2 instrument purge flow test in preparation for launch Feb. 24. The spacecraft sits atop Orbital Sciences' Taurus XL rocket. At right is a portion of the umbilical tower attached to the upper stack. The spacecraft sits atop Orbital Sciences' Taurus XL rocket. At right is a portion of the umbilical tower attached to the upper stack. 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 Jim Stowers, Orbital Sciences

VANDENBERG AIR FORCE BASE, Calif. -- 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

VANDENBERG AIR FORCE BASE, Calif. -- With the fairing door off, Orbital Sciences' Glenn Weigle and Brett Gladish maneuver into position to take the GN2 flow reading from NASA's Orbiting Carbon Observatory, or OCO, spacecraft. At left, Jose Castillo and Mark Neuse stand by to replace the fairing door when the OCO operation is complete. The spacecraft sits atop Orbital Sciences' Taurus XL rocket. At right is a portion of the umbilical tower attached to the upper stack. The spacecraft sits atop Orbital Sciences' Taurus XL rocket. At right is a portion of the umbilical tower attached to the upper stack. 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 Jim Stowers, Orbital Sciences

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, Orbital Sciences Engineer Jose Castillo maneuvers the bucket truck at right into position over the fairing access door on NASA's Orbiting Carbon Observatory, or OCO. Glenn Weigle of Orbital Satellite Systems Group is on the bucket at left. Weigle 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. OCO is scheduled to launch Feb. 24 aboard an Orbital Sciences' Taurus XL rocket. Photo credit: NASA/Richard Nielsen, KSC

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, Orbital Sciences Engineer Jose Castillo maneuvers the bucket truck at right into position over the fairing access door on NASA's Orbiting Carbon Observatory, or OCO. Glenn Weigle of Orbital Satellite Systems Group is on the bucket at left. Weigle 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. OCO is scheduled to launch Feb. 24 aboard an Orbital Sciences' Taurus XL rocket. Photo credit: NASA/Richard Nielsen, KSC

VANDENBERG AIR FORCE BASE, Calif. -- 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 a bucket out of camera range at left, who is waiting 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

VANDENBERG AIR FORCE BASE, Calif. -- With the fairing door off, Orbital Sciences' Glenn Weigle and Brett Gladish take the GN2 flow reading on NASA's Orbiting Carbon Observatory, or OCO, spacecraft on Launch Complex 576-E at Vandenberg Air Force Base in California. The encapsulated OCO tops Orbital Sciences' Taurus XL rocket, which is scheduled to launch Feb. 24. The spacecraft sits atop Orbital Sciences' Taurus XL rocket. At right is a portion of the umbilical tower attached to the upper stack. The spacecraft sits atop Orbital Sciences' Taurus XL rocket. At right is a portion of the umbilical tower attached to the upper stack. 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 Jim Stowers, Orbital Sciences

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, NASA's Orbiting Carbon Observatory, OCO, upper stack is lowered toward the Stage 0 motor of the Taurus XL vehicle. The upper stack consists of Stages 1, 2 and 3 of the Taurus. 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

VANDENBERG AIR FORCE BASE, Calif. -- Just before dawn on Launch Complex 576-E at Vandenberg Air Force Base in California, a crane is attached to the tent covering NASA's Orbiting Carbon Observatory, or OCO, the Taurus XL upper stack and the umbilical tower. The tent will be removed to allow OCO to be raised. 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

VANDENBERG AIR FORCE BASE, Calif. – After arrival of the Stage 0 motor for the Taurus XL launch vehicle at Vandenberg Air Force Base in California, a crane lifts off the protective cage. The motor will be transported to Orbital Sciences' Hangar 1555. The Taurus XL will launch NASA's Orbiting Carbon Observatory, or OCO, spacecraft targeted for Jan. 15. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. – At Vandenberg Air Force Base in California, a crane lifts the Taurus XL Stage 0 motor to move it to a flatbed truck. The motor will be transported to Orbital Sciences' Hangar 1555. The Taurus XL will launch NASA's Orbiting Carbon Observatory, or OCO, spacecraft targeted for Jan. 15. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. – The Taurus XL Stage 0 motor has been moved into Orbital Sciences' Hangar 1555 at Vandenberg Air Force Base in California. The Taurus XL will launch NASA's Orbiting Carbon Observatory, or OCO, spacecraft targeted for Jan. 15. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. – At Vandenberg Air Force Base in California, a crane lifts the Taurus XL Stage 0 motor to move it to a flatbed truck. The motor will be transported to Orbital Sciences' Hangar 1555. The Taurus XL will launch NASA's Orbiting Carbon Observatory, or OCO, spacecraft targeted for Jan. 15. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. – After arrival of the Stage 0 motor for the Taurus XL launch vehicle at Vandenberg Air Force Base in California, a crane lifts off the protective shipping cover. The motor will be transported to Orbital Sciences' Hangar 1555. The Taurus XL will launch NASA's Orbiting Carbon Observatory, or OCO, spacecraft targeted for Jan. 15. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. – At Vandenberg Air Force Base in California, a worker secures a crane on the Taurus XL Stage 0 motor. The motor will be lifted onto a flatbed truck and transported to Orbital Sciences' Hangar 1555. The Taurus XL will launch NASA's Orbiting Carbon Observatory, or OCO, spacecraft targeted for Jan. 15. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. – At Vandenberg Air Force Base in California, a crane lifts the Taurus XL Stage 0 motor to move it to a flatbed truck. The motor will be transported to Orbital Sciences' Hangar 1555. The Taurus XL will launch NASA's Orbiting Carbon Observatory, or OCO, spacecraft targeted for Jan. 15. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. – The Taurus XL Stage 0 motor has been moved into Orbital Sciences' Hangar 1555 at Vandenberg Air Force Base in California. The Taurus XL will launch NASA's Orbiting Carbon Observatory, or OCO, spacecraft targeted for Jan. 15. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. – The Taurus XL Stage 0 motor is moved into Orbital Sciences' Hangar 1555 at Vandenberg Air Force Base in California. The Taurus XL will launch NASA's Orbiting Carbon Observatory, or OCO, spacecraft targeted for Jan. 15. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. – The Taurus XL Stage 0 motor is moved into Orbital Sciences' Hangar 1555 at Vandenberg Air Force Base in California. The Taurus XL will launch NASA's Orbiting Carbon Observatory, or OCO, spacecraft targeted for Jan. 15. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. – After arrival of the Stage 0 motor for the Taurus XL launch vehicle at Vandenberg Air Force Base in California, a crane lifts off the protective cage. The motor will be transported to Orbital Sciences' Hangar 1555. The Taurus XL will launch NASA's Orbiting Carbon Observatory, or OCO, spacecraft targeted for Jan. 15. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. – The Stage 0 motor for the Taurus XL launch vehicle arrives at Vandenberg Air Force Base in California. The motor will be transported to Orbital Sciences' Hangar 1555. The Taurus XL will launch NASA's Orbiting Carbon Observatory, or OCO, spacecraft targeted for Jan. 15. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. – At Vandenberg Air Force Base in California, a worker secures a crane on the Taurus XL Stage 0 motor. The motor will be lifted onto a flatbed truck and transported to Orbital Sciences' Hangar 1555. The Taurus XL will launch NASA's Orbiting Carbon Observatory, or OCO, spacecraft targeted for Jan. 15. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. – After its arrival at Vandenberg Air Force Base in California, the Taurus XL Stage 0 motor is transported to Orbital Sciences' Hangar 1555. The Taurus XL will launch NASA's Orbiting Carbon Observatory, or OCO, spacecraft targeted for Jan. 15. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, NASA's Orbiting Carbon Observatory, or OCO, undergoes closeouts for launch. OCO is atop the Orbital Sciences' Taurus XL rocket. OCO is scheduled for launch on 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 credit: NASA/Richard Nielsen, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, NASA's Orbiting Carbon Observatory, or OCO, undergoes closeouts for launch. OCO is atop the Orbital Sciences' Taurus XL rocket. OCO is scheduled for launch on 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 credit: NASA/Richard Nielsen, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, NASA's Orbiting Carbon Observatory, or OCO, undergoes closeouts for launch. OCO is atop the Orbital Sciences' Taurus XL rocket. OCO is scheduled for launch on 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 credit: NASA/Richard Nielsen, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, two cranes have raised NASA's Orbiting Carbon Observatory, or OCO, spacecraft to vertical. OCO will be lifted and attached to the waiting Stage 0 motor of the Taurus XL launch vehicle in the tower. The OCO is attached to the upper stack, consisting of Stages 1, 2 and 3 of the Taurus. 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

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, Orbital Sciences' Taurus XL rocket and NASA's Orbiting Carbon Observatory, or OCO, on top, are bathed in light for the night. The spacecraft has been undergoing final closeouts for launch. OCO is scheduled for launch on 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 credit: NASA/Richard Nielsen, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, two cranes raise NASA's Orbiting Carbon Observatory, or OCO, spacecraft to vertical for attachment to the waiting Stage 0 motor of the Taurus XL launch vehicle in the tower. The OCO is attached to the upper stack, consisting of Stages 1, 2 and 3 of the Taurus. 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

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, two cranes are used to lift NASA's Orbiting Carbon Observatory, or OCO, spacecraft. It will be raised to vertical and attached to the waiting Stage 0 motor of the Taurus XL launch vehicle in the tower. The OCO is attached to the upper stack, consisting of Stages 1, 2 and 3 of the Taurus. 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

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, two cranes raise NASA's Orbiting Carbon Observatory, or OCO, spacecraft to vertical for attachment to the waiting Stage 0 motor of the Taurus XL launch vehicle in the tower. The OCO is attached to the upper stack, consisting of Stages 1, 2 and 3 of the Taurus. 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

VANDENBERG AIR FORCE BASE, Calif. -- 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

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, NASA's Orbiting Carbon Observatory, or OCO, upper stack is prepared to be raised to vertical. The upper stack, consists of stages 1, 2 and 3 of the Taurus. 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

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, NASA's Orbiting Carbon Observatory, or OCO, upper stack is prepared to be raised to vertical. The upper stack, consists of Stages 1, 2 and 3 of Orbital Sciences' Taurus XL rocket as well as the encapsulated OCO spacecraft. Once vertical, the upper stack will be lifted and attached to the Taurus Stage 0, at left. OCO is scheduled for launch aboard the Taurus 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/Dan Liberotti, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, the crane, at left, is attached to NASA's Orbiting Carbon Observatory, or OCO, upper stack to lift and attach the spacecraft to Orbital Sciences' Taurus XL rocket's Stage 0 (within the scaffolding). A portion of the umbilical tower (above it) is attached to the upper stack. The upper stack consists of Stages 1, 2 and 3 of the Taurus as well as the encapsulated OCO spacecraft. OCO is scheduled for launch aboard the Taurus 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/Dan Liberotti, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- 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 Orbital Sciences' Taurus XL vehicle. The upper stack consists of Stages 1, 2 and 3 of the Taurus, as well as the encapsulated OCO spacecraft. 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 credit: NASA/Richard Nielsen, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, NASA's Orbiting Carbon Observatory, or OCO, upper stack is prepared to be raised to vertical. The upper stack, consists of Stages 1, 2 and 3 of Orbital Sciences' Taurus XL rocket as well as the encapsulated OCO spacecraft. Once vertical, the upper stack will be lifted and attached to the Taurus Stage 0, at left. OCO is scheduled for launch aboard the Taurus 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/Dan Liberotti, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, workers prepare NASA's Orbiting Carbon Observatory, or OCO, upper stack for attachment to Orbital Sciences' Taurus XL rocket's Stage 0. The upper stack consists of Stages 1, 2 and 3 of the Taurus as well as the encapsulated OCO spacecraft. Orbital Sciences workers put the non-flight environmental shield over the fairing prior to erection. A portion of the umbilical tower (above it) is attached to the upper stack. OCO is scheduled for launch aboard the Taurus 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/Dan Liberotti, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, the crane in the foreground moves the cables used to lower NASA's Orbiting Carbon Observatory, OCO, upper stack onto to the Taurus XL Stage 0 motor behind it. The upper stack consists of Stages 1, 2 and 3 of the Taurus, as well as the encapsulated OCO spacecraft. 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 credit: NASA/Richard Nielsen, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, the cables from the crane overhead are removed from NASA's Orbiting Carbon Observatory, OCO, upper stack. The upper stack was lowered onto the Stage 0 motor of Orbital Sciences' Taurus XL vehicle. The upper stack consists of Stages 1, 2 and 3 of the Taurus, as well as the encapsulated OCO spacecraft. 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 credit: NASA/Richard Nielsen, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, NASA's Orbiting Carbon Observatory, OCO, upper stack is lifted high for transfer to the waiting Stage 0 motor of the Taurus XL vehicle at left. The upper stack consists of Stages 1, 2 and 3 of the Taurus. 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

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, cranes wait in the early morning hours for winds to subside in order to lift the tent that covers NASA's Orbiting Carbon Observatory, or OCO, the Taurus XL upper stack and the umbilical tower. The upper stack, consists of stages 1, 2 and 3 of the Taurus. 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

VANDENBERG AIR FORCE BASE, Calif. -- Just before dawn on Launch Complex 576-E at Vandenberg Air Force Base in California, a crane lifts the tent covering (at left) NASA's Orbiting Carbon Observatory, or OCO, the Taurus XL upper stack and the umbilical tower. The tent removal will allow OCO to be raised. 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

VANDENBERG AIR FORCE BASE, Calif. -- Space Launch Complex 576-E, Vandenberg Air Force Base in California, a worker checks the integration of the Taurus XL Stages 1 and 2. The Taurus is the launch vehicle for NASA's Orbiting Carbon Observatory, called OCO, a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The observatory is targeted to launch Feb. 23 from Space Launch Complex 576-E at Vandenberg. Photo credit: NASA/VAFB

VANDENBERG AIR FORCE BASE, Calif. -- Space Launch Complex 576-E, Vandenberg Air Force Base in California, a worker checks the integration of the Taurus XL Stages 1 and 2. The Taurus is the launch vehicle for NASA's Orbiting Carbon Observatory, called OCO, a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The observatory is targeted to launch Feb. 23 from Space Launch Complex 576-E at Vandenberg. Photo credit: NASA/VAFB

VANDENBERG AIR FORCE BASE, Calif. -- Stage 0 of the Taurus XL launch vehicle for the Orbiting Carbon Observatory arrives at complex 576E at Vandenberg Air Force Base in California. It will be mated with stages 1, 2 and 3 for the launch of OCO. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. It is scheduled to launch Feb. 23. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. --In Space Launch Complex 576-E, Vandenberg Air Force Base in California, Stages 1 and 2 of the Taurus XL launch vehicle are being integrated for NASA's Orbiting Carbon Observatory, called OCO. OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The observatory is targeted to launch Feb. 23 from Space Launch Complex 576-E at Vandenberg. Photo credit: NASA/VAFB

VANDENBERG AIR FORCE BASE, Calif. --In Space Launch Complex 576-E, Vandenberg Air Force Base in California, Stages 1 and 2 of the Taurus XL launch vehicle are being integrated for NASA's Orbiting Carbon Observatory, called OCO. OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The observatory is targeted to launch Feb. 23 from Space Launch Complex 576-E at Vandenberg. Photo credit: NASA/VAFB

VANDENBERG AIR FORCE BASE, Calif. --In Space Launch Complex 576-E, Vandenberg Air Force Base in California, Stages 1 and 2 of the Taurus XL launch vehicle are being integrated for NASA's Orbiting Carbon Observatory, called OCO. OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The observatory is targeted to launch Feb. 23 from Space Launch Complex 576-E at Vandenberg. Photo credit: NASA/VAFB

VANDENBERG AIR FORCE BASE, Calif. -- Stage 0 of the Taurus XL launch vehicle for the Orbiting Carbon Observatory arrives at complex 576E at Vandenberg Air Force Base in California. It will be mated with stages 1, 2 and 3 for the launch of OCO. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. It is scheduled to launch Feb. 23. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- The avionics are mated to stage 2 of the Taurus XL launch vehicle for the Orbiting Carbon Observatory at Vandenberg Air Force Base in California. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The launch of OCO is scheduled for Feb. 23. Photo credit: NASA/VAFB

VANDENBERG AIR FORCE BASE, Calif. --In Space Launch Complex 576-E, Vandenberg Air Force Base in California, Stages 1 and 2 of the Taurus XL launch vehicle are being integrated for NASA's Orbiting Carbon Observatory, called OCO. OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The observatory is targeted to launch Feb. 23 from Space Launch Complex 576-E at Vandenberg. Photo credit: NASA/VAFB

VANDENBERG AIR FORCE BASE, Calif. -- On Space Launch Complex 576-E at Vandenberg Air Force Base in California, cranes are in position to move the tent where the upper stage of Orbital Sciences' Taurus XL rocket is ready to be moved and lifted into the tower for stacking. 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

VANDENBERG AIR FORCE BASE, Calif. – Stages 1, 2 and 3 of Orbital Sciences’ Taurus XL launch vehicle for NASA’s Orbiting Carbon Observatory, or OCO, have arrived and are prepared for erection at Space Launch Complex 576-E at Vandenberg Air Force Base in California. The OCO is an Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The observatory will collect precise global measurements of carbon dioxide in the Earth's atmosphere. Scientists will analyze the data returned to better understand the natural processes and human activities that regulate the abundance and distribution of this important greenhouse gas. Launch is targeted for 1:51:30 a.m. PST Feb. 24. Photo credit: VAFB

VANDENBERG AIR FORCE BASE, Calif. -- On Space Launch Complex 576-E at Vandenberg Air Force Base in California, NASA's Orbiting Carbon Observatory, or OCO, spacecraft displays the mission decals. 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

VANDENBERG AIR FORCE BASE, Calif. – Stages 1, 2 and 3 of Orbital Sciences’ Taurus XL launch vehicle for NASA’s Orbiting Carbon Observatory, or OCO, have arrived and are prepared for lifting onto Space Launch Complex 576-E at Vandenberg Air Force Base in California. The OCO is an Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The observatory will collect precise global measurements of carbon dioxide in the Earth's atmosphere. Scientists will analyze the data returned to better understand the natural processes and human activities that regulate the abundance and distribution of this important greenhouse gas. Launch is targeted for 1:51:30 a.m. PST Feb. 24. Photo credit: VAFB

VANDENBERG AIR FORCE BASE, Calif. -- On Space Launch Complex 576-E at Vandenberg Air Force Base in California, a worker applies a mission decal to NASA's Orbiting Carbon Observatory, or OCO. 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

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, workers remove the umbilical tower attached to Orbital Sciences' Taurus XL rocket. Atop the rocket is NASA's Orbiting Carbon Observatory, or OCO, which is scheduled to launch 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/Richard Nielsen, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, workers remove the umbilical tower attached to Orbital Sciences' Taurus XL rocket. Atop the rocket is NASA's Orbiting Carbon Observatory, or OCO, which is scheduled to launch 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/Richard Nielsen, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, workers remove the umbilical tower attached to Orbital Sciences' Taurus XL rocket. Atop the rocket is NASA's Orbiting Carbon Observatory, or OCO, which is scheduled to launch 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/Richard Nielsen, VAFB

VANDENBERG AIR FORCE BASE, Calif. – Workers prepare to erect Stages 1, 2 and 3 of Orbital Sciences’ Taurus XL launch vehicle for NASA’s Orbiting Carbon Observatory, or OCO, at Space Launch Complex 576-E at Vandenberg Air Force Base in California. The OCO is an Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The observatory will collect precise global measurements of carbon dioxide in the Earth's atmosphere. Scientists will analyze the data returned to better understand the natural processes and human activities that regulate the abundance and distribution of this important greenhouse gas. Launch is targeted for 1:51:30 a.m. PST Feb. 24. Photo credit: VAFB

VANDENBERG AIR FORCE BASE, Calif. -- Stages 1, 2 and 3 of Orbital Sciences’ Taurus XL launch vehicle for NASA’s Orbiting Carbon Observatory, or OCO, arrive at Space Launch Complex 576-E at Vandenberg Air Force Base in California. The OCO is an Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The observatory will collect precise global measurements of carbon dioxide in the Earth's atmosphere. Scientists will analyze the data returned to better understand the natural processes and human activities that regulate the abundance and distribution of this important greenhouse gas. Launch is targeted for 1:51:30 a.m. PST Feb. 24. Photo credit: VAFB

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, workers in the bucket trucks are securing the fairing ducting, GN2 purge line, and cable harnesses to the umbilical mast attached to Orbital Sciences' Taurus XL rocket. Atop the rocket is NASA's Orbiting Carbon Observatory, or OCO, which is scheduled to launch 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/Richard Nielsen, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- Stages 1, 2 and 3 of Orbital Sciences’ Taurus XL launch vehicle for NASA’s Orbiting Carbon Observatory, or OCO, are transported from Building 1555 to Space Launch Complex 576-E at Vandenberg Air Force Base in California. The OCO is an Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The observatory will collect precise global measurements of carbon dioxide in the Earth's atmosphere. Scientists will analyze the data returned to better understand the natural processes and human activities that regulate the abundance and distribution of this important greenhouse gas. Launch is targeted for 1:51:30 a.m. PST Feb. 24. Photo credit: VAFB

VANDENBERG AIR FORCE BASE, Calif. -- On Space Launch Complex 576-E at Vandenberg Air Force Base in California, a worker applies a mission decal onto NASA's Orbiting Carbon Observatory, or OCO. 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

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, workers remove the scaffolding surrounding Orbital Sciences' Taurus XL rocket. Atop the rocket is NASA's Orbiting Carbon Observatory, or OCO, which is scheduled to launch 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/Richard Nielsen, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- Stages 1, 2 and 3 of Orbital Sciences’ Taurus XL launch vehicle for NASA’s Orbiting Carbon Observatory, or OCO, are parked under a tent at Space Launch Complex 576-E at Vandenberg Air Force Base in California. The OCO is an Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The observatory will collect precise global measurements of carbon dioxide in the Earth's atmosphere. Scientists will analyze the data returned to better understand the natural processes and human activities that regulate the abundance and distribution of this important greenhouse gas. Launch is targeted for 1:51:30 a.m. PST Feb. 24. Photo credit: VAFB

VANDENBERG AIR FORCE BASE, Calif. -- On Space Launch Complex 576-E at Vandenberg Air Force Base in California, a worker applies a mission decal to NASA's Orbiting Carbon Observatory, or 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

CAPE CANAVERAL, Fla. -- In Building 1555 at Vandenberg Air Force Base in California, workers do a fit check on the mating of the Stage 1 to Stage 2 motors for the Taurus XL rocket that will launch NASA's Orbiting Carbon Observatory, or OCO, spacecraft. At right can be seen the avionics shelf. The avionics skirt, a graphite/epoxy structure, supports the avionics shelf and carries the primary structural loads from the fairing and payload cone. The aluminum avionics shelf supports the third stage avionics. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The launch of OCO is targeted for January. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- At complex 576E at Vandenberg Air Force Base in California, a crane lifts Stage 0 of the Taurus XL launch vehicle for the Orbiting Carbon Observatory from its transporter. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. It is scheduled to launch Feb. 23. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- At complex 576E at Vandenberg Air Force Base in California, a crane raises Stage 0 of the Taurus XL launch vehicle for the Orbiting Carbon Observatory from its transporter. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. It is scheduled to launch Feb. 23. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- At complex 576E at Vandenberg Air Force Base in California, a crane lifts Stage 0 of the Taurus XL launch vehicle for the Orbiting Carbon Observatory from its transporter. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. It is scheduled to launch Feb. 23. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- At complex 576E at Vandenberg Air Force Base in California, a crane lifts Stage 0 of the Taurus XL launch vehicle for the Orbiting Carbon Observatory from its transporter. The OCO is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. It is scheduled to launch Feb. 23. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- The Stage 1, 2 and 3 motors of the Taurus XL rocket are being prepared for transfer to Space Launch Complex 576-E at Vandenberg Air Force Base in California. The Taurus is the launch vehicle for NASA's Orbiting Carbon Observatory, or OCO, which is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The observatory is scheduled to launch 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. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- The Stage 1, 2 and 3 motors of the Taurus XL rocket are being prepared for transfer to Space Launch Complex 576-E at Vandenberg Air Force Base in California. The Taurus is the launch vehicle for NASA's Orbiting Carbon Observatory, or OCO, which is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The observatory is scheduled to launch 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. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- The Stage 1, 2 and 3 motors of the Taurus XL rocket are being prepared for transfer to Space Launch Complex 576-E at Vandenberg Air Force Base in California. The Taurus is the launch vehicle for NASA's Orbiting Carbon Observatory, or OCO, which is a new Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The observatory is scheduled to launch 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. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- The Encapsulated Cargo Element (ECE) containing NASA's Orbiting Carbon Observatory, or OCO, is lowered to a horizontal position after arrival at Space Launch Complex 576-E at Vandenberg Air Force Base in California. 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. Photo credit: NASA/Randy Beaudoin, VAFB

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. Photo credit: NASA/Robert Hargreaves Jr., VAFB

VANDENBERG AIR FORCE BASE, Calif. -- The second half of the fairing, at right, is moved closer to 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 the effect that these changes may have on the Earth's climate. Photo credit: NASA/Robert Hargreaves Jr., VAFB

VANDENBERG AIR FORCE BASE, Calif. -- On Space Launch Complex 576-E at Vandenberg Air Force Base in California, the encapsulated cargo element containing NASA’s Orbiting Carbon Observatory, or OCO, enters the tent for integration with Orbital Sciences’ Taurus XL launch vehicle, at right. The OCO is an Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The observatory will collect precise global measurements of carbon dioxide in the Earth's atmosphere. Scientists will analyze the data returned to better understand the natural processes and human activities that regulate the abundance and distribution of this important greenhouse gas. Launch is targeted for Feb. 24 from Space Launch Complex 576-E at Vandenberg. Photo credit: VAFB/Wayne North

VANDENBERG AIR FORCE BASE, Calif. --The Encapsulated Cargo Element (ECE) containing NASA's Orbiting Carbon Observatory, or OCO, is lowered to a horizontal position after arrival at Space Launch Complex 576-E at Vandenberg Air Force Base in California. 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. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- NASA's Orbiting Carbon Observatory, or OCO, arrives at Space Launch Complex 576-E at Vandenberg Air Force Base in California. 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. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- Workers secure the installation of the fairing around NASA's Orbiting Carbon Observatory, or OCO. 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 the effect that these changes may have on the Earth's climate. Photo credit: NASA/Robert Hargreaves Jr., VAFB

VANDENBERG AIR FORCE BASE, Calif. -- The Encapsulated Cargo Element containing NASA's Orbiting Carbon Observatory, or OCO, is lifted from its transporter on Space Launch Complex 576-E at Vandenberg Air Force Base in California. 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. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. --The Encapsulated Cargo Element containing NASA's Orbiting Carbon Observatory, or OCO, lowered to a horizontal position on a transporter, is moved under a protective tent after arrival at Space Launch Complex 576-E at Vandenberg Air Force Base in California. 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. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- NASA's Orbiting Carbon Observatory, or OCO, is transported to Space Launch Complex 576-E at Vandenberg Air Force Base in California. 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. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- On Launch Complex 576-E at Vandenberg Air Force Base in California, workers prepare NASA's Orbiting Carbon Observatory, or OCO, upper stack for attachment to the Stage 0. Orbital Sciences workers put the non-flight environmental shield over the fairing prior to erection. A portion of the umbilical tower (above it) is attached to the upper stack. The umbilical tower will be erected along with the upper stack. 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

VANDENBERG AIR FORCE BASE, Calif. -- NASA's Orbiting Carbon Observatory, or OCO, arrives at Space Launch Complex 576-E at Vandenberg Air Force Base in California. The spacecraft is scheduled for launch aboard Orbital Sciences' Taurus XL rocket, being erected at left, 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. Photo credit: NASA/Randy Beaudoin, VAFB

VANDENBERG AIR FORCE BASE, Calif. -- At left, the second half of the fairing is moved toward NASA's Orbiting Carbon Observatory, or OCO, at right, for 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 the effect that these changes may have on the Earth's climate. Photo credit: NASA/Robert Hargreaves Jr., VAFB

VANDENBERG AIR FORCE BASE, Calif. -- On Space Launch Complex 576-E at Vandenberg Air Force Base in California, scaffolding is built around Stage 0 of the Taurus XL launch vehicle for NASA’s Orbiting Carbon Observatory, or OCO, stacked on the launch mount. An umbilical tower is being erected on the pad using the portable crane. Stage 0 utilizes a Castor 120 Motor. The OCO is an Earth-orbiting mission sponsored by NASA's Earth System Science Pathfinder Program. The observatory will collect precise global measurements of carbon dioxide in the Earth's atmosphere. Scientists will analyze the data returned to better understand the natural processes and human activities that regulate the abundance and distribution of this important greenhouse gas. Launch is targeted for Feb. 24 from Space Launch Complex 576-E at Vandenberg. Photo credit: VAFB/Wayne North