NASA has posted an image of its new solar-electric propulsion thruster, which uses xenon ions for propulsion.
The engine in the photo, blue with the glow of xenon gas, is being considered to become a part of NASA's Asteroid Retrieval Initiative, a proposed program to robotically capture a small near-Earth asteroid and redirect it to a stable orbit around Earth. Such an asteroid could then be visited and explored by astronauts.
Often mentioned in science fiction novels, ion propulsion is one of the most efficient known ways to travel through space. "The ion propulsion system's efficient use of fuel and electrical power enable modern spacecraft to travel farther, faster, and cheaper than any other propulsion technology currently available," claims NASA.
The image was taken through a porthole in a vacuum chamber at NASA's Jet Propulsion Laboratory, Pasadena, Calif., where the engine is being tested.