Engine Model: Sert-I Cesium. Designer: Hughes. Developed in: 1964. Propellants: Electric/Cesium. Thrust(vac): 0.0000 N (0.0000 lbf). Isp: 8,050 sec. Chambers: 1. Country: USA. Status: In Development, 1962-1964. This 8 cm diameter cesium contact ion engine was designed to operate at 0.6 kW and provide 5.6 naN of thrust and a specific impulse of 8050 s. The cesium flow was controlled by a boiler and the porous tungsten ionizer electrode. Beam power supply voltage was 4500 V.