The NASA Solar Electric Propulsion Technology Application Readiness (NSTAR) program developed a 2.3 kW ion engine for use as a primary propulsion engine for orbit transfer and intra-solar system trajectories. The NSTAR engine was the primary propulsion for the Deep Space 1 (DS-1) comet and asteroid rendezvous probe. In NSTAR, xenon ions were efficiently produced in a discharge chamber via collisions between neutral atom and energetic electrons generated by a hollow cathode in the discharge chamber. The ions were accelerated through two fine grids with roughly a 1300 V difference between them for 2.3 kW operation. The ion beam was neutralized by electrons emitted from a second hollow cathode external to the discharge assembly.
The NSTAR program provided a single string, primary ion propulsion system for the Deep Space I spacecraft. The 30 cm ion thruster operated over a 0.5 kW to 2.3 kW input power range providing thrust from 19 mN to 92 mN. The specific impulse ranged from 1900 s at 0.5 kW to 3100 s at 2.3 kW. The flight thruster and PPU design requirements were derived with .the aid of about 50 development tests and a series of wear-tests at NASA LeRC and JPL of 2000 hours, 1000 hours, and 8193 hours using engineering model thrusters. The flight-set masses for the thruster. PPU, and DCIU were 8.2 kg, 14.77 kg, and 2.51 kg, respectively. About 1.7 kg mass was added to the PPU top plate to satisfy the DSI micrometeoroid requirements. The power cable between the thruster and PPU was comprised of two segments which were connected at a field junction. The thruster cable mass was 0.95 kg, and the PPU cable mass was 0.77 kg. The xenon storage and feed system dry mass was about 20.5 kg. A total of 82 kg of xenon was loaded for the flight. Thrusters and PPUs were manufactured by Hughes, and the DCIU was built by Spectrum Astro, Inc. The feed system development was a collaborative effort between JPL and Moog,Inc.
Electrical Input Power: 2.30 kW.
Thrust: 0.0920 N (0.0200 lbf).
Specific impulse: 3,100 s.