U.S. Air Force To Test Hall Thruster On X-37B Space Plane

The U.S. Air Force made an unusual announcement on Monday that its secret X-37B space plane will host a Hall thruster experiment during Orbital Test Vehicle mission 4, the fourth flight of the X-37B reusable flight vehicle scheduled to launch on May 20, 2015 from Cape Canaveral, Florida.

A Hall thruster is a type of electric propulsion device that produces thrust by ionizing and accelerating a noble gas, usually xenon. While producing comparatively low thrust relative to conventional rocket engines, Hall thrusters provide significantly greater specific impulse, or fuel economy. This results in increased payload carrying capacity and a greater number of on-orbit maneuvers for a spacecraft using Hall thrusters rather than traditional rocket engines.