Chapter 18 - Electrostatic Solar Sail

Abstract

The solar sail has become well known after much discussion in the scientific literature as a thin continuous plastic film, covered by sunlight-reflecting appliquéd aluminum. Earlier, there were attempts to launch and operate solar sails in near-Earth space, and there are experimental projects planned for long powered space voyages. However, as currently envisioned, the solar sail has essential disadvantages. Solar light pressure in space is very low and consequently the solar sail has to be very large in area. Also, it is difficult to unfold and unfurl the solar sail in space. In addition, it is necessary to have a rigid framework to support the thin material. Such frameworks usually have great mass and, therefore, the spacecraft's acceleration is small. This chapter proposes to discard standard solar sail technology (continuous plastic aluminum-coated film) with the intention of using millions of small, very thin aluminum-charged plates, and to release these plates from a spacecraft, instigated by an electrostatic field. Using this new technology, the solar sail composed of millions of plates can be made to a gigantic area but have very low mass. The acceleration of this new kind of solar sail may be as much as 300 times that is achieved by an ordinary solar sail. The electrostatic solar sail can even reach a speed of about 300 km/s (in a special maneuver up to 600–800 km/s). The electrostatic solar sail may be used to move a large spaceship, or to act as an artificial Moon illuminating a huge region of the Earth's surface.