The MICROLAS concept: Precise thrust generation in the µN range by laser ablation

Experimental work and hydrodynamic simulations on the MICROLAS concept of a pulsed laser-ablative microthruster are presented. Impulse bit generation in the nNs range is affected by laser parameters like wavelength, pulse duration, beam incidence angle and polarization as well as the optical and thermal properties of the chosen propellant material. A parameter study for the optimum working point is carried out yielding two different operation modes with respect to laser pulse duration. Thrust in µN range is generated by repetitive laser ablation events under fixed and well-defined process parameters allowing for thrust level control by the laser pulse repetition rate through several orders of magnitude. Thrust noise, e.g., by mechanical motion for continuous propellant supply, can be minimized since laser beam can access every part of the propellant surface without any mechanical motion. Electro-optical beam-steering constitutes a promising technology for an inertia-free setup enabling high precision thrust generation.