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 dadla.UUCP
Path: utzoo!linus!philabs!cmcl2!seismo!harvard!talcott!panda!genrad!decvax!tektronix!teklds!dadla!jamesp
From: jamesp@dadla.UUCP (Jim Perkins)
Newsgroups: net.space
Subject: Re: Nuclear Rockets
Message-ID: <333@dadla.UUCP>
Date: Tue, 23-Jul-85 11:44:20 EDT
Article-I.D.: dadla.333
Posted: Tue Jul 23 11:44:20 1985
Date-Received: Fri, 26-Jul-85 04:18:27 EDT
References: <1839@mordor.UUCP> <939@teddy.UUCP>
Reply-To: jamesp@dadla.UUCP (Jim Perkins)
Organization: Tektronix, Beaverton OR
Lines: 35

In article <939@teddy.UUCP> rdp@teddy.UUCP (Richard D. Pierce) writes:
>In article <1839@mordor.UUCP> @S1-A.ARPA,@MIT-MC:jheimann@bbnccy writes:
>>From: John H. Heimann <jheimann@BBNCCY.ARPA>
>>
>>
>>	Back in the 'sixties, there were a number of programs (funded, I think,
>>by NASA and what was then AEC) to develop nuclear powered space propulsion
>>schemes.... 
>
>The use of nuclear propulsion tended (in the case of the non-explosive
>technique) to result in extremely high exhaust velocities and very high
>efficiencies, but extremely low thrusts. I recall hearing of thrusts in the
>neighborhood of ounces! Such propulsion methods are useful when you can
>tolerate long durations of firings (months or years) and do not need
>tremendous accelerations. For near-earth and earth-moon manned missions, and
>the like, what was needed was lots of thrust over short periods of time, the
>kinf of things chemical rockets are good at.


Quite true.  I believe you are talking about some sort of nuclear/ion
engine... wasn't there some type that used a hot reactor to heat, say,
hydrogen gas that produced respectible thrust?  The method as I understood it
had a an inner and an outer fissile cylinder, and the reaction mass was passed
between them, heated, and expelled to the exterior.  Other methods used
gaseous(?) fissile materials, and used a helical mixing method and centrifugal
reaction chambers where the fissioning gas was concentrated on the exterior of
the reaction chamber.  All these methods were of course theoretical.  I
wonder how much research has been done on these and what the results were...

===============================================================================
|  James T. Perkins | uucp: ...!decvax!tektronix!dadla!jamesp | "Roads?! Where
|	\ | /	    | \@_ (snail):	4635 SW Hillside Dr.  | we're going we
|      -- O --	    |			Portland, OR 97221    | don't NEED 
|	/ | \	    | Bell: 		(503)292-4614	      | roads..."
===============================================================================