Before revision: ion thrusters and Hall-effect thrusters) for high-specific-impulse propulsion, solar sails (using sunlight pressure) for continuous thrust without the need for traditional rockets, additive manufacturing (3D printing) and advanced materials (e.g.
After revision: ion thrusters and Hall-effect thrusters) for high-specific-impulse propulsion, solar sails (using solar radiation pressure) for continuous thrust without the need for traditional rockets, additive manufacturing (3D printing) and advanced materials (e.g.