Path: utzoo!utgpu!watmath!clyde!att!pacbell!ames!vsi1!daver!mfgfoc!mike
From: mike@mfgfoc.uucp (Mike Thompson)
Newsgroups: sci.space.shuttle
Subject: Re: QUESTION: Shuttle round trips to the moon?
Message-ID: <524@mfgfoc.uucp>
Date: 10 Jan 89 21:31:16 GMT
References: <14549@oberon.USC.EDU>
Organization: Focus Semiconductor Sys, Sunnyvale
Lines: 42

From article <14549@oberon.USC.EDU>, by annala@neuro.usc.edu (A J Annala):
> Can the shuttle fly to the moon, land, and take off again to return
> to the earth.  Keep in mind the moon has 1/6 the gravitational pull
> of the earth.  Let's assume for the moment that there is adequate
> solid flat landing surface prepared on the moon for the landing.

Assuming we could get the shuttle out of earth orbit, the main problem would
be slowing the craft from some 20,000 mile per hour to a few hundred mph. 
The shuttle uses atmospheric friction to slow down from orbital speeds by 
converting its kenetic energy into thermal energy.  This is why the heat 
tiles on the shuttle are so important during descent from orbit.  On the
moon, there is virtually no atmosphere so a shuttle like craft would have
to rely solely on retro-rockets to land.  Even on the moon, it would take
a tremendous amount of fuel to soft land something the mass of the shuttle
on it.  

Now Mars is a different story.  Because of the design and weight of the
shuttle, it will never get further than a few hundred miles from Earth, 
but a shuttle type device could be used to explore Mars.  In fact, I have
read that NASA has done studies and built small prototypes of robot 
planes which could be dropped into the Martian atmosphere and would be 
capable of flying around for several days (weeks?) taking detailed pictures
of the surface of the planet.  Pictures of the plane looked somewhat like
a U2 spyplane with a propeller on the back.  Yes, a propeller which was 
connected to a type of internal combustion engine which did not require 
oxygen to run.  I think it used Hydrazaline (sp?) as its fuel.  Radio control
prototypes were actually made and tested out at high altitudes on Earth to
simulate the thin Martian atmosphere.  I think I read about this type
of craft in a Popular Science article some 10 years ago.  I would think that
such a mission would be very exciting, to bad our congressmen don't agree.

Hope this helps answer your question of why the shuttle can't land on the
moon.  If it could just make it to lunar orbit would be great, but it simply
weighs to much to be sent higher than a few hundred miles.

Mike Thompson

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Michael P. Thompson                      FOCUS Semiconductor Systems, Inc.
net: (sun!daver!mfgfoc!mike)             570 Maude Court
att: (408) 738-0600 ext 370              Sunnyvale, CA  94086 USA
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