The Planetary Society is here yet again with its new solar sail program. Unlike its first solar sail that ended up in the ocean instead of orbit, this new project called LightSail is expected to be a success. The organization announced its plan to propel a spacecraft on sunlight alone by the end of 2010. Under this new program, three separate spacecrafts will be launched over a period of several years.
The $1 million anonymous donation boosted project that unveiled on the 75th anniversary of astronomer Carl Sagan’s birth will start with LightSail-1, which will demonstrate that sunlight alone can propel a spacecraft into Earth orbit. The LightSail-1 that will be constructed by Stellar Exploration Inc. of San Luis Obispo, Calif will use three Cubesat spacecraft, out of which one will form the central electronics and control module, while the other two will house the solar sail module. Cameras, additional sensors, and a control system will be added to the basic Cubesat electronics bus.
The solar sails are propelled by reflected light pressure and not solar wind. The push of photons against a mirror-bright surface is capable of continuously changing orbital energy and spacecraft velocity. The LightSail-1 will launch with its four triangular Mylar sails packaged in a volume equal to about three quarts and unfurl to an area of more than 340 square feet, resembling a giant diamond-shaped kite. It will orbit at an altitude of nearly 500 miles and operate for just a few days to determine if it can be controlled, and to measure the orbital acceleration.
The LightSail-2 spacecraft is planned for higher altitude orbits, while the LightSail-3 is intended to be sent to the Sun-Earth Libration Point, L1, where solar sails could be permanently placed as solar weather stations, monitoring the geomagnetic storms from the sun that potentially endanger electrical grids and satellite systems around Earth.