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To: LibWhacker

Is this anything like the “light sail”?

Solar sails (also called light sails or photon sails) are a proposed method of spacecraft propulsion using radiation pressure exerted by sunlight on large mirrors. A useful analogy 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 spacecraft. 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 craft, a factor that must be included in spacecraft design.[1]

The total force exerted on an 800 by 800 meter solar sail, for example, is about 5 newtons (1.1 lbf) at Earth’s distance from the Sun,[2] 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.

https://en.m.wikipedia.org/wiki/Solar_sail


16 posted on 09/17/2018 5:41:18 PM PDT by ETL (Obama-Hillary, REAL Russia collusion! Uranium-One Deal, Missile Defense, Iran Deal, Nukes: Click ETL)
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To: ETL

No, I don’t think it’s the same at all. The solar sail idea is well established and has some interesting possibilities. This QI stuff really does sound like junk science to me, but we’ll see. I just don’t understand any of it.


18 posted on 09/17/2018 6:11:02 PM PDT by LibWhacker
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To: ETL

What happens when the solar pressure drops off?....or you get caught in cross currents from other stars?


26 posted on 09/17/2018 9:47:43 PM PDT by Getready (Wisdom is more valuable than gold and diamonds, and harder to find.)
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