Newsgroups: sci.space.shuttle
Path: utzoo!henry
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: Propellant velocity
Message-ID: <1991May22.164754.22298@zoo.toronto.edu>
Date: Wed, 22 May 1991 16:47:54 GMT
References: <12344@uwm.edu>
Organization: U of Toronto Zoology

In article <12344@uwm.edu> markh@csd4.csd.uwm.edu (Mark William Hopkins) writes:
>   What is the velocity of the fuel propellant relative to the ship, in the
>case of (1) fuel from the booster during boost, and (2) fuel from the ship
>itself during orbital flight?

Boost vs. orbital flight makes no difference; engine technology, and to
some extent ambient atmospheric pressure, do.  Chemical-rocket exhaust
velocities are typically a few thousands of meters per second.  3000-3500
is good for a non-hydrogen system, 4500 is good for hydrogen.  You won't
get large improvements on the latter with chemical fuels.

>   How fast can NASA-generated technology expel propellant?

If you mean technology that is available for production use now, numbers
on the order of the above are it.  If you mean technology that NASA was
investigating 20-30 years ago, an improvement of several orders of
magnitude should be possible if you're willing to fund development.
Thrusts will not be high enough, mostly, for use in launch to orbit,
but 25-year-old technology would be ample for huge improvements in
maneuvering once in orbit.

>   What does the latest research on this issue have to say?

What latest research?  There is only the barest dribble of research,
and no development of flight-worthy hardware to speak of.
-- 
And the bean-counter replied,           | Henry Spencer @ U of Toronto Zoology
"beans are more important".             |  henry@zoo.toronto.edu  utzoo!henry
