Solar sail

Solar sails (also called light sails, especially when they use light sources other than the Sun) are a proposed form of spacecraft propulsion utilizing large membrane mirrors. Radiation pressure is small and decreases by the square of the distance from the sun, but unlike rockets, solar sails require no fuel. Although the thrust is small, it continues as long as the sun shines and the sail exists.

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Solar collectors, temperature-control panels and sun shades are occasionally used as expedient solar sails, to help ordinary spacecraft and satellites make minor corrections to their attitude and orbit without using fuel. This conserves fuel that would otherwise be used for maneuvering and attitude control. A few have even had small purpose-built solar sails for this use. Some unmanned spacecraft (such as Pioneer 10) have substantially extended their service lives with this practice.

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The science of solar sails is well-proven, but the technology to manage large solar sails is still undeveloped. Mission planners are not yet willing to risk multimillion dollar missions on unproven solar sail unfolding and steering mechanisms. This neglect has inspired some enthusiasts to attempt private development of the technology.

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The concept was first proposed by German astronomer Johannes Kepler in the seventeenth century.http://www.rednova.com/news/space/151474/measuring_up_to_a_solar_sail/ It was again proposed by Friedrich Zander in the late 1920s and gradually refined over the decades.

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Light: Light is electromagnetic radiation with a wavelength that is visible to the eye (visible light) or, in a technical or scientific setting, electromagnetic radiation of any wavelength. The three basic dimensions of light (i.e., all electromagnetic radiation) are:...

Sun: :: For the astrological significance of the Sun, see Solar system in astrology....

Spacecraft propulsion: Spacecraft propulsion is used to change the velocity of spacecraft and artificial satellites, or in short, to provide delta-v. There are many different methods. Each method has drawbacks and advantages, and spacecraft propulsion is an active area of research. Most spacecraft today are propelled by h...

Solar sail related Images and Photos (experimental)

Solar I	Solar Wind	Solar Space	Solar Flares
Sail Carts	Solar Eclipse	Solar Strata I	Sail Away II
Sail Away Bay	Solar Heights I	Solar Square IV	Solar Energy Kit