A still from footage of a recent NASA/JPL test of a new magnetoplasmadynamic (MPD) thruster that runs on lithium metal vapor and is capable of reaching power levels far beyond today’s electric propulsion systems. (Image credit: NASA/JPL) A new ion engine has been tested in a lab, proving itself to be 25 times more powerful than NASA's current state-of-the-art one. This advanced technology could one day assist humans in reaching Mars. Ion engines are very different to the usual sort of thrusters that burn chemical propellant. Using electromagnetic fields, they accelerate ions — charged atoms — out through a nozzle to provide thrust, hence they are often described as using "electric propulsion." Though they are slow at first, these engines' thrust can build up incrementally to achieve high velocities, and because they use 90% less propellant than chemical rockets, ion engines also reduce the mass of a spacecraft and make launch less expensive.…