"Researchers say they may have discovered the solution to a problem that has long hindered progress with a novel form of plasma propulsion that could one day carry humans to distant planets, and potentially launch a new era of space exploration.

The helicon double-layer thruster (HDLT) is a prototype plasma thruster propulsion system that works by injecting gas into an open-ended source tube, where radio frequency AC power produced by an antenna surrounding it electromagnetically ionizes the gas. Within this highly charged plasma, a low-frequency electromagnetic helicon wave is excited by the antenna’s electromagnetic field, further heating the plasma."