The present invention is for a system and a method of VUV photoionization of fullerene and derivative clusters followed by their thermal effusion for a practical energy-efficient and economically-viable high thrust density ion thruster. By taking advantage of the state-of-the-art high intensity VUV photon sources, present invention is able to provide much softer ionization with minimal internal energy deposition than the ionization in the electron impact or charge exchange type ionization in plasma environment used in conventional ion thrusters. Because the invention eliminates the need of additional gas for forming discharge plasma, it permits simpler and lighter structures than the conventional fullerene thrusters with significantly enhanced propellant-usage efficiencies, thrust to power ratios, and thrust to weight ratios. Because the present invention employs softer VUV photoionization, it permits the usage of heavier and more complex fullerene derivatives, nanotubes, and nanotube derivatives than fullerene clusters for fuels without significantly fragmenting them.