The thruster for the Scatha experiment consisted of one electron bombardment engines using xenon propellant. The thruster anode diameter was 3.6 cm, and an Yttrium-doped tungsten neutralizer was used. Beam power supply voltage was 1000 to 2000 V, and the power per thruster was 0.03 to 0.045 kW, producing 0.14 mN thrust at a specific impulse of 350 seconds. About 0.3 kg of propellant was carried. The longest ground test prior to launch was 600 hours, and in space the engine was operated intermittently over a 247 day period.