Escape From Planetary Gravitational Fields by Use of Solar Sails

An escape maneuver by use of solar radiation pressure is computed for an initially circular orbit in the plane of the ecliptic of a planetary gravitational field. The flat sail is rotated about its axis at half the revolution rate about the planet. It is assumed that the sun is the only body that provides a flux of radiant energy, and that the sail perfectly reflects this energy specularly from either surface. Effects of extraneous gravitational fields, including that of the sun and moons (if any), are all neglected, as are other perturbing phenomena (such as atmospheric drag, magnetic fields, solar winds, meteoric showers, re-radiation from the planet's surface, etc.). Under these assumptions it is found that for a practical case of escape from Earth's gravitational field, solar sailing could accelerate a payload to escape condition in a period of time of the order of several months, during which time it would pass the vicinity of the moon's orbit about Earth.