NASA’s Evolutionary Xenon Thruster (NEXT) project has completed the longest duration test for a Space propulsion system (48,000 hours/5 1/2 years). This look inside the thrusters discharge chamber shows how it works.

(may be broke/outdated!)
NASA’s Evolutionary Xenon Thruster (NEXT) project has completed the longest duration test for a Space propulsion system (48,000 hours/5 1/2 years). This look inside the thrusters discharge chamber shows how it works.