This photo gallery shows how the Orbital Sciences Taurus XL rocket was prepared and assembled at Vandenberg Air Force Base to launch NASA's Orbiting Carbon Observatory.

The upper three stages of the Taurus XL rocket are seen in Hangar 1555 last August. Photo credit: Christopher Miller/Spaceflight Now   The upper stages rest on the processing platform. Photo credit: Christopher Miller/Spaceflight Now   A closeup of the Taurus' fourth stage, the Orion 38 motor. Photo credit: Christopher Miller/Spaceflight Now   See larger panorama here Photo credit: Christopher Miller/Spaceflight Now   The Castor 120 motor that serves at the Taurus rocket's first stage arrives at Orbital's Hangar 1555. Photo credit: NASA   Technicians work to integrate the upper three stages of the Taurus rocket. Photo credit: NASA   Technicians work to integrate the upper three stages of the Taurus rocket. Photo credit: NASA   At Space Launch Complex 576-East, the first stage of the Taurus is erected. Photo credit: NASA/Randy Beaudoin, VAFB   The upper stages are prepared to depart Hangar 1555. Photo credit: NASA/Randy Beaudoin, VAFB   A special trailer hauls the upper stages to the launch pad. Photo credit: NASA   The upper stages are placed inside the temporary tent at the launch pad. Photo credit: NASA   In the satellite cleanroom, the Orbiting Carbon Observatory is encapsulated in the rocket's nose cone. Photo credit: NASA/Robert Hargreaves Jr., VAFB   The Orbiting Carbon Observatory is driven to the launch pad. Photo credit: NASA/Randy Beaudoin, VAFB   The satellite is rotated horizontally to enter the pad tent. Photo credit: NASA/Randy Beaudoin, VAFB   OCO enters the tent to join the rocket's upper three stages. Photo credit: NASA/Randy Beaudoin, VAFB   The mission logos are added to the rocket's nose cone. Photo credit: NASA/Randy Beaudoin, VAFB   A crane removes the tent covering the upper stack before its hoisting. Photo credit: NASA/Randy Beaudoin, VAFB   The combined payload and stages are readied to go vertical. Photo credit: NASA/Randy Beaudoin, VAFB   Two cranes work in tandem to hoist the upper stack off the horizontal transporter. Photo credit: NASA/Randy Beaudoin, VAFB   The upper stack is turned to the vertical position. Photo credit: NASA/Randy Beaudoin, VAFB   The upper stack is raised toward the pad. Photo credit: NASA/Randy Beaudoin, VAFB   The rocket is maneuvered into position atop the waiting first stage. Photo credit: NASA/Randy Beaudoin, VAFB