The first X-37B Orbital Test Vehicle waits in the encapsulation cell of the Evolved Expendable Launch vehicle April 5, 2010, at the Astrotech facility in Titusville, Fla. Half of the Atlas V five-meter fairing is visible in the background. The Hall thruster being tested on this flight provide significantly greater specific impulse, or fuel economy and may lead to increased payload carrying capacity and a greater number of on-orbit maneuvers for a spacecraft using Hall thrusters rather than traditional rocket engines. (Courtesy photo)