philipl@azure.UUCP (Philip Lantz) (03/02/85)
> If you really want high performance, especially in low Earth orbit, one > intriguing notion is to take a Drexler aluminum sail and punch it full > of very tiny (smaller than a wavelength of light) holes. Holes which are > significantly smaller than a wavelength of light will not affect the > reflectivity of the sail, but they will lighten it considerably. Just > as interesting, air molecules at orbital altitudes are independent of > each other and will go through tiny holes just as easily as through big > ones. Not only does one get (say) a 75% weight reduction, one also gets > a 75% air-drag reduction. Wouldn't holes "significantly smaller than a wavelength of light" also be significantly smaller than air molecules? Punching holes to reduce weight sounds like a good idea, but I'm not convinced it would reduce the drag any. Showing my ignorance, Philip Lantz tektronix!bronze!philipl
henry@utzoo.UUCP (Henry Spencer) (03/06/85)
> Wouldn't holes "significantly smaller than a wavelength of light" also > be significantly smaller than air molecules? Punching holes to reduce > weight sounds like a good idea, but I'm not convinced it would reduce > the drag any. Air molecules are several orders of magnitude smaller than the wavelength of visible light, so it does indeed work. -- Henry Spencer @ U of Toronto Zoology {allegra,ihnp4,linus,decvax}!utzoo!henry