From: strider@clotho.acm.rpi.edu (Greg Moore)
Subject: Re: DC vs Shuttle capabilities
Organization: The Voice of Fate
Date: Thu, 17 Dec 1992 03:21:07 GMT

In article <ewright.724354656@convex.convex.com> ewright@convex.com (Edward V. Wright) writes:
>In <g9g2v_p@rpi.edu> strider@clotho.acm.rpi.edu (Greg Moore) writes:
>
>>	You missed my point.  If your crew compartment is in the cargo
>>bay, where do you put the satellite?
>
>If your cargo bay is full of troops, where do you put the transport 
>vehicles? 
>
>Answer: In the other airplane.
>

	Gee, thanks for the snide answer.  Now, my original point was
on rendezvous and repair.  So, now we have to get 3 objects in close
proximity to each other.  You've just made the problem at least 50%
tougher.  And now you have to transfer between craft.  More 
difficuly.

>
>>	Granted, but that's not what I meant.  Will you have enough time
>>to rendevous and capture the satelite?  It took what 3 days for the
>>shuttle to capture Intelsat VI? That's aday more than DC-?.
>>Also, what type of fuel margin would DC-1 have for IN-orbit
>>manevours?
>
>That's what tankers are for.
>
	Again, another craft.

>
>>	Use it yes, but use it for what it can be used for economically.
>>Let's see, we've added an airlock, an arm, additional on-orbit capacity.
>>Hmm, that adds up, and add complexity.  Yes, let's ok at possibilities,
>>but not claim t they are definites.
>
>Take a look at the C-130 Hercules.  How many variants are flying,
>in both military and commercial service?  Hint:  It's a lot more
>than four.
>

	Hint, they are flying.  You are talking about a paper=airplane
and saying it will do all this and more.  I'm saying, build it, fly it,
and see what happens.

>
>>	I have a question about this.  EOT and LM should require roughly
>>the same amount of fuel, no? (as I recall, the energy to get into lunar
>>orbit is about the same as GEO? I'm ignoring landing here).  But how
>>economical is it to transport that fuel TO orbit?  Am I correct in 
>>remembering you saying about 10 DC-1 flights?
>
>Depends on your assumptions.  I've done some back-of-the-envelope
>calculations.  If you can set up an oxygen-extraction plant on the
>Moon, your costs go way down if you land the DC with its LOX tank
>dry.  (This would allow the DC to carry extra cargo, probably
>using external attach points.)  It might even be advantageous
>to put payloads into GEO from the Moon instead of directly from
>the Earth.
>
	Right, that works fine once you've built your power-plant
on the moon.  I'm talking at first.  It seems to me that someone
here is forgetting the middle step of testing and flying the thing.

>
>>What about thermal protection.  LM won't require any to land on 
>>the moon, but what about reentering earth orbit or earth landing?
>
>But the DC-LM will require periodic maintenance and, until you
>have a fully equipped service station on the Moon, that will
>require bringing it back to Earth.
>
	Right, but what are your thermal protection requirements?
Are they higher? If so, will the current system work?  If not,
what?  Gee, don't want to use shuttle tiles... that would
affect your turn-around. :-)
 
>
>


Xref: sparky sci.space:17817 sci.astro:13246