Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!rochester!dietz
From: dietz@cs.rochester.edu (Paul Dietz)
Newsgroups: sci.space
Subject: Re: Solid State Fusion for Launchers
Message-ID: <1989Apr2.133451.27254@cs.rochester.edu>
Date: 2 Apr 89 17:34:51 GMT
References: <1989Mar31.163051.5961@cs.rochester.edu> <1989Apr1.224916.22484@utzoo.uucp>
Reply-To: dietz@cs.rochester.edu (Paul Dietz)
Organization: U of Rochester, CS Dept, Rochester, NY
Lines: 34

henry@utzoo.uucp (Henry Spencer) writes:

>>The second possibility is to use a smaller fusion reactor to preheat
>>fuel and/or oxidizer before injection into a conventional chemical
>>engine.
>
>I doubt the practicality of this.  Existing oxyhydrogen rockets already
>run fuel-rich partly to *cool* the exhaust a bit (and thus reduce thermal
>dissociation of water into oxygen and hydrogen).

So, a fusion preheated chemical rocket would be even more fuel rich.
In the limit, no oxygen is used at all, and the system is a purely nuclear
rocket.

I can also imagine a nuclear scramrocket.  A fusion NERVA rocket is used
as a fuel injector into a supersonic airstream, which serves as a thrust
augmentor.  This might be a better use of a nuclear rocket, since
peak power required is lower.

>If the power densities
>stay low, the big use will probably be as a power source for electrical
>propulsion in space.

I have a feelin that power densities can be increased markedly.  For
example, go to thinner pieces of Pd.  If lithium is involved in the
reaction, use purified Li6 (boosts the power density by a factor of
5).  Boost the amount of deuterium in the lattice by upping the
current density.  Try DT instead of D.

I've heard a report that the reaction doesn't work at high enough
temperatures, though.  Time to look for a better metal.

	Paul F. Dietz
	dietz@cs.rochester.edu