An ion thruster is a type of electric propulsion system used in spacecraft. It works by ionizing a propellant, usually a noble gas like xenon, and then using electric fields to accelerate the ions, creating thrust. This method is highly efficient, allowing spacecraft to travel long distances with less fuel compared to traditional chemical rockets. Ion thrusters produce a small amount of thrust over a long period, making them ideal for deep-space missions. They have been used in various missions, including NASA's Dawn spacecraft, which explored the asteroid belt. Their ability to operate in the vacuum of space makes them a valuable technology for future exploration.