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From: dls@mtgzz.UUCP (d.l.skran)
Newsgroups: net.space
Subject: Re: Nuclear Rockets
Message-ID: <994@mtgzz.UUCP>
Date: Tue, 30-Jul-85 23:34:46 EDT
Article-I.D.: mtgzz.994
Posted: Tue Jul 30 23:34:46 1985
Date-Received: Thu, 1-Aug-85 21:35:41 EDT
References: <1839@mordor.UUCP>, <939@teddy.UUCP>
Organization: AT&T Information Systems Labs, Middletown NJ
Lines: 35


Why projects were canceled:

My understanding is as follows:

Orion: 1)testing would violate test-ban treaty
       2)MORE IMPORTANT: no clear mission requirement for aircraft carrier
         size rockets. Military decided they didn't need one.

Nerva: 1)insufficient advantage over chemical rockets to
         compenstate for all the extra trouble.

	Note: Nerva was not a "low thrust" program. Its thrust was
      	quite similar to chemical rockets. I believe you are confusing
	ion & plasma rockets(which are low thrust) with nuclear rockets.
	Frequently, an ion/plasma rocket design might call for a nuclear
	reactor to produce electricity, but other power sources could
	have been used. 

Why not today:

Nerva: same reason, insufficient advantage for all the trouble.

Orion: the smaller the explosions, the higher the efficiency. Hence,
       many people are working on particle/laser beam induced fusion
       which could be used to create a rocket an order of magnitude better
       than orion.
  
       Really, though, we've got no guts, no reason to build Orion.
      

Read Niven & Pournelle's new novel Footfall for some idea of what an
Orion ship might be like and how it could be used.

Dale