What is Solar sails: Definition and 11 Discussions

Solar sails (also called light sails or photon sails) are a method of spacecraft propulsion using radiation pressure exerted by sunlight on large mirrors. A number of spaceflight missions to test solar propulsion and navigation have been proposed since the 1980s. The first spacecraft to make use of the technology was IKAROS, launched in 2010.
A useful analogy to solar sailing may be a sailing boat; the light exerting a force on the mirrors is akin to a sail being blown by the wind. High-energy laser beams could be used as an alternative light source to exert much greater force than would be possible using sunlight, a concept known as beam sailing. Solar sail craft offer the possibility of low-cost operations combined with long operating lifetimes. Since they have few moving parts and use no propellant, they can potentially be used numerous times for delivery of payloads.
Solar sails use a phenomenon that has a proven, measured effect on astrodynamics. Solar pressure affects all spacecraft, whether in interplanetary space or in orbit around a planet or small body. A typical spacecraft going to Mars, for example, will be displaced thousands of kilometers by solar pressure, so the effects must be accounted for in trajectory planning, which has been done since the time of the earliest interplanetary spacecraft of the 1960s. Solar pressure also affects the orientation of a spacecraft, a factor that must be included in spacecraft design.The total force exerted on an 800 by 800 metre solar sail, for example, is about 5 newtons (1.1 lbf) at Earth's distance from the Sun, making it a low-thrust propulsion system, similar to spacecraft propelled by electric engines, but as it uses no propellant, that force is exerted almost constantly and the collective effect over time is great enough to be considered a potential manner of propelling spacecraft.

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    B Could solar sails be used as turbines for power generation?

    It seems as though two advantages to using a solar sail turbine system instead of solar panels would be (1) the sails may not degrade as quickly as the solar panels, and (2) a sail turbine system may be lighter than a solar panel (and therefore less expensive to launch into orbit). The drawback...
  2. D

    Solar Sails -- What are the current limitations?

    What are the current limitations with solar sails and why are they not used with greater frequency? I have heard of hydrogen blistering -- is that a significant issue?
  3. S

    My arXiv preprint on a crewed interstellar spacecraft

    Hi everybody, I would like to share with you a crewed interstellar spacecraft which I have designed and called Solar One. It employs a combination of 3 propulsion methods: nuclear fusion, beam-powered propulsion , and photon propulsion. Basically, several compact fusion reactors power a...
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    A Calculation of the "lightness number" for solar sails

    Hello, In the wikipedia article about solar sails the lightness number is mentioned and the calculation is the characteristic acceleration ac divided by the Sun´s local gravity (distance: 1AU): λ = ac / 5.93 why do they use 5,93 m/s^2 for the sun´s gravity and not 274 m/s^2?
  5. N

    On board a laser powered solar sail

    Can an on board laser be used to propel a solar sail spacecraft if the laser is pointed at the sails ? Would Newtons third law affect the laser and maybe prevent the ship from moving ? Thank you for answering my very ignorant questions. NineNinjas911
  6. R

    Materials for space applications?

    So I'm working on this project for a inflatable solar sail (so a spherical solar sail) and we are really only verifying the deployment of the sail in space (from a cubesat)...We are doing a mock PDR and I need to find info on the sail we'll be using. My job is to find an "off the shelf"...
  7. T

    Photons in Fiber Optics V Solar Sails

    Solar sails use the push of photons on a mirror. Would it work to use the push of photons in the atoms in fiber optic cables so the question is would there be push and how much on 1 mile of a space train 50 feet wide with 1 foot thick of fiber optics. Here's how I think it would be nearly...
  8. Enis

    B What are the applications of solar sails?

    I'm working on a project on solar sails, and I was wondering if you could provide me with some information. I couldn't find much on the internet, except highly technical research. In fact, even the Wikipedia article is too technical for my purposes. If you know about this stuff or have any...
  9. B

    How do solar sails work?

    I briefly researched this and all i found out was that the light pushes the sail as it is reflected off of its surface. So i am left wondering how this is possible because photons apparently have no mass therefor they can't push anything. I'm sorry if this is ignorant i am no physicist...
  10. P

    Exploring the Possibilities of Solar Sails

    can anyone explain to me what requirements are needed in order to escape to infinity so I can tackle part a? Thanks.
  11. G

    Understanding Photon Collisions with Solar Sails

    I have some questions about solar sails. Basically, what happens to the photon? I am under the impression that the "sail" is a giant mirror that reflects photons striking it. Since photons have momentum, they impart some of this momentum to this mirror. Is this correct? But that must mean...