Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 (Tek) 9/28/84 based on 9/17/84; site azure.UUCP Path: utzoo!watmath!clyde!burl!ulysses!allegra!bellcore!decvax!tektronix!teklds!azure!philipl From: philipl@azure.UUCP (Philip Lantz) Newsgroups: net.space Subject: Re: Light Sails with holes Message-ID: <133@azure.UUCP> Date: Sat, 2-Mar-85 15:40:33 EST Article-I.D.: azure.133 Posted: Sat Mar 2 15:40:33 1985 Date-Received: Tue, 5-Mar-85 02:19:28 EST References: <595@mordor.UUCP> <5095@utzoo.UUCP> Organization: Tektronix, Beaverton OR Lines: 18 > 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