Newsgroups: sci.space.shuttle
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: shuttle escape systems
Message-ID: <1989Oct18.174154.23242@utzoo.uucp>
Organization: U of Toronto Zoology
References: <538.252A3A3B@mamab.FIDONET.ORG> <34577@srcsip.UUCP> <126311@sun.Eng.Sun.COM> <1307@accuvax.nwu.edu> <15596@netnews.upenn.edu> <1321@accuvax.nwu.edu>
Date: Wed, 18 Oct 89 17:41:54 GMT

In article <1321@accuvax.nwu.edu> phil@delta.eecs.nwu.edu (William LeFebvre) writes:
>I am of the impression that solid fuel gives greater force for the
>weight than liquid fuel does.  Is that not true?

In general, correct.  For one thing, it's easier to build solid motors
in large sizes (i.e. high thrusts).  For another, the average molecular 
weight of the exhaust is higher, which is bad for getting maximum velocity
but good for getting maximum thrust.

This is why they're so popular as strap-on boosters.
-- 
A bit of tolerance is worth a  |     Henry Spencer at U of Toronto Zoology
megabyte of flaming.           | uunet!attcan!utzoo!henry henry@zoo.toronto.edu