Electric Propulsion (EP) is a suitable propulsion technology for satellite and space missions, offering advantages over chemical propulsion in various aspects including fuel consumption hence launch cost. The cusped field thruster (CFT) offers advantages over other types of EP such as the gridded ion thruster and Hall effect thruster, with enhanced electron confinement owing to the magnetic mirror and reduced particle loss effects at the dielectric wall. The increasing demand for performance improvement of the propulsion system while downscaling for micro-satellite class platforms has led to considerable efforts dedicated to physical modeling and performance characterization of downsized CFT. In the present study a multi-objective design optimization (MDO) study has been conducted to characterize the performance to maximize three performance objectives of downscaled CFT, namely, thrust, total efficiency, and specific impulse defined by common design parameters, namely, anode voltage, anode current, mass flow rate and geometric configuration. Particle-in-cell simulations have been performed for the selected design points identified in MDO studies for verification by accurately accounting for phenomena and performance losses that originate from uncertainties and complexities associated with the thruster design and physics.