The NASA Solar Technology Application Readiness is a type of spacecraft ion thruster that uses two fine grids to accelerate ions.
The NASA Solar Technology Application Readiness (NSTAR) is a type of spacecraft ion thruster called electrostatic ion thruster. The ions are accelerated through two fine grids with roughly a 1300 V difference between them for 2.3 kW operation, with a thrust of 20-92 mN, a specific impulse of 19000-30500 Ns/kg (1950-3100 s) and a total impulse capability of 2.65 x10 Ns. 
