Propulsion solar sails

Jet Propulsion Laboratory. "Sail Film Materials and Supporting Structures for a Solar Sail" JPL Report 720-9 Pasadena, CA , 1979. 

The field of propulsion deals with the means by which aircraft, missiles, and spacecraft are propelled toward their destinations. Subjects of development include propellers and rotors driven by internal combustion engines or jet engines, rockets powered by solid- or liquid-fueled engines, spacecraft powered by ion engines, solar sails or nuclear reactors, and matter-antimatter engines. Propulsion system metrics include thrust, power, cycle efficiency, propulsion efficiency, specific impulse, and thrust-specific fuel consumption. Advances in this field have enabled hiunanity to travel across the world in a few hours, visit space and the Moon, and send probes to distant planets. 

Solar sails, consisting of large membrane mirrors that would utilize solar radiation pressure, have been proposed for spacecraft propulsion. Unlike rockets, the thrust is small, but because solar sails require no fuel and operate continuously when exposed to sunlight, significant speeds can be achieved when they are deployed in space. 

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