Plasmonic force propulsion for small spacecraft

Plasmonic force propulsion uses solar light focused on deep-subwavelength nanostructures to excite strong optical forces that accelerate and expel nanoparticle propellant. The concept was assessed within the context of precision pointing and position control for nano/pico-satellites. Plasmonic force fields were numerically simulated, propulsion performance predicted and then used to evaluate spacecraft position control resolution and pointing precision. Results for a conceptual design of a plasmonic thruster that has 35 layers, 86 array columns, multi-stage length of 5 mm, a 5-cm-diameter light focusing lens, and uses 100 nm polystyrene nanoparticles expelled at a rate of 1×10⁶ per sec would have a thrust of 250 nN, specific impulse of 10 sec, and minimum impulse bit of 50 pN-s. The thruster mass and volume are estimated at 100 g and 50 cm³, respectively. Results predict plasmonic force propulsion can enhance the state-of-the-art in small spacecraft position and attitude control by 1-2 orders of magnitude. This has the potential to enable advanced missions that require ultra-fine pointing precision to less than 0.1 milliarcsecond.