Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/18/84; site rochester.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!allegra!bellcore!decvax!genrad!panda!talcott!harvard!seismo!rochester!sher
From: sher@rochester.UUCP (David Sher)
Newsgroups: net.space,net.physics
Subject: Re: ultralight probes
Message-ID: <9883@rochester.UUCP>
Date: Mon, 27-May-85 10:17:05 EDT
Article-I.D.: rocheste.9883
Posted: Mon May 27 10:17:05 1985
Date-Received: Thu, 30-May-85 00:44:28 EDT
References: <5630@utzoo.UUCP>
Reply-To: sher@rochester.UUCP (David Sher)
Organization: U. of Rochester, CS Dept.
Lines: 15
Keywords: light sail photoelectric
Xref: watmath net.space:4046 net.physics:2518
Summary: Building a lightsail out of photo electric material

In response to the article on the possibility an ultra-light space probe moved
by a light sail, has anyone considerred the possibility of building
a lightsail out of photo-electric material?  I know that thin film
processes are already well advanced (as shown by the common light
powered pocket calculator).  I suspect that a light-sail can be made
out of anything (except neutronium :-) as long as its thin.  
This would solve the problem of a power source for the probe,  
a few thousand square meters is probably sufficient power collection area
for most purposes.  It might just be possible to use the ion bombardment
as a power source since that should cause a charge differential between
a lighted and shaded object in space.  The main problem would be 
grounding and the behavior of circuitry in highly charged environments.
The max efficiency loss due to photoelectric effect on a light sail is
50%.  Enuf thoughts, any comments?
-David