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From: henry@utzoo.UUCP (Henry Spencer)
Newsgroups: net.space
Subject: Re: sail with holes
Message-ID: <5196@utzoo.UUCP>
Date: Sat, 9-Mar-85 20:41:19 EST
Article-I.D.: utzoo.5196
Posted: Sat Mar  9 20:41:19 1985
Date-Received: Sat, 9-Mar-85 20:41:19 EST
References: <221@npois.UUCP>
Organization: U of Toronto Zoology
Lines: 13

> 	Clearly holes under a quarter wave length could work to reduce
> weight and drag, while not altering reflectiveness much. I have trouble
> imagining the process by which this stuff is made. How could a few square
> miles of this stuff be cheap ?

That's precisely the hard part.  Ultrathin aluminum is not hard to make
by vapor deposition in vacuum, but punching lots of submicroscopic
holes in it isn't simple.  Perhaps a photolithographic process like
that used in ICs, using shortwave ultraviolet so the holes are small
by visible-light standards?  But how to make it fast and cheap...?
-- 
				Henry Spencer @ U of Toronto Zoology
				{allegra,ihnp4,linus,decvax}!utzoo!henry