sentences:  Although this thrust is very small, the engines are also extremely efficient; the 66 kg of xenon reaction mass can change the speed of the spacecraft by up to .The spacecraft has four redundant reaction wheels and a chemical reaction control system featuring twelve thrusters for attitude control (orientation) and orbital control at the asteroid.The chemical thrusters use hydrazine and MON-3, with a total mass of 48 kg of chemical propellant.