Question

Spacecraft propulsion systems based on ‘solar sails’ are being explored. These systems use radiation pressure on sails made of thin reflecting foils (mirrors) for propulsion, similar to the way wind propels a sailboat. (a) What sail area, A is required for the radiation pressure provided by a star of mass Ms at a distance R to just balance the gravitational attraction of the star? Take the mass of the ship and its sail to be m, and the intensity of the starlight at R to be I. (b) If R is the mean Earth-Sun distance with the sunlight intensity at the earth taken to be 1.4 kW/m2 , what size sail would be required to just balance the gravitational attraction of the Sun with m = 1500 kg?

Answer 1