NetNews Usenet Archive 1993 #1/NN_1993_1.iso/spool/sci/space/18884

Text File | 1993-01-07 | 4.6 KB | 98 lines

Newsgroups: sci.space
Path: sparky!uunet!elroy.jpl.nasa.gov!usc!wupost!udel!rochester!cantaloupe.srv.cs.cmu.edu!crabapple.srv.cs.cmu.edu![e-mail]
From: [e-mail] (John Roberts)
Subject: Re: DC cost estimates
Message-ID: <[e-mail]>
X-Added: Forwarded by Space Digest
Sender: [e-mail]
Organization: National Institute of Standards and Technology formerly National Bureau of Standards
Original-Sender: [e-mail]
Distribution: sci
Date: Thu, 7 Jan 1993 05:48:54 GMT
Approved: bboard-news_gateway
Lines: 83


-From: [e-mail] (Allen W. Sherzer)
-Subject: Re: DC cost estimates
-Date: 4 Jan 93 03:06:42 GMT

-In article <[e-mail]> [e-mail] (John Roberts) writes:
->I hope you understand what I mean by the economic term "opportunity cost".

-Sure I know what opportunity cost is. But I always assumed that the
-higher opportunity cost was by using Shuttle. I admit I haven't worked
-out the details but I suspect that for a years Shuttle costs we could
-could find a way to use Mir for the locker experiments and redesign the
-few payloads which MUST fly on Shuttle. That would allow us to switch to
-far cheaper expendables if DC fails and still save money.

I think cooperative ventures with the CIS space program are a good idea, but
I don't think we should rely exclusively on Russian manned launch services
while DC is being developed. There's a difference between carpooling with
your next door neighbor Fred to save money and selling your car and relying on
Fred to drive you to work for the next five years. Fred might get sick, or
get mad at you, or his car might break down.

With reference to your posts on adapting Soyuz to fit on US launchers,
bear in mind that this might take nearly as long as getting DC-1 operational.
So that's still several years without US manned launch capability (assuming
the Shuttle were terminated immediately), and if DC lives up to its optimistic
expectations, it will immediately kill the interim launch system. So all
of that money and effort would be expended to get an interim system that's
likely to be used for perhaps as little as a year or two.

->the fact that it's in use indicates that
->those who pay for it (NASA, the government in general, and the public in
->general) get get some value out of it.

-But what is that value and is it worth the money spent? NASA's highest
-priority is to keep its centers funded. To government, Shuttle is a jobs
-program.

If that's their main goal, then they're not doing a very good job of it -
the social program people seem to be much better at it. :-)  I'm inclined to
believe that most of the people involved in the NASA programs are there
largely because they think what they're doing is worthwhile.

->There are in fact a considerable
->number of missions scheduled over the next few years. If the Shuttle program
->were cancelled today, those missions would also have to be cancelled, or at
->least deferred.

-Sure, but are those missions being conducted in the most cost effective
-way? To date, nobody has been able to show that they have been.

Probably not. But that's not the only valid criterion. One would hope that
the "total value" of conducting these missions at the time they're conducted
is greater than the cost.

In planning a mission, one of the cost features that must be included
is the uncertainties involved. If it is not certain that a given utility
will be available at the planned time of the mission, then the risk to
the timely accomplishment of the mission must be considered as a cost.

-However, this is all moot. Shuttle cannot be killed; it has too big a
-constituency. All we can do is hope it doesn't drag us all down with it.

Then trying to emphasize that DC is primarily a way of killing the Shuttle
(and further, that the Shuttle should be killed before DC is even proven
to work and available for use) does no good to the DC program, and could
cause considerable political harm to the DC effort.

->One question I'm not sure has been addressed before: is the DC-1 expected to
->provide for a "shirtsleeve" environment access tube to the cargo bay, like
->the Shuttle? In other words, would a "mini-Spacelab" be a viable option for
->a DC-1 payload?

-A mini-spacelab would be viable. In fact, the DC design allows for delta-V,
-and duration tradeoffs which make it attractive. there may or may not be
-access however, between the flight crew and cargo bay (but there is no
-reason there couldn't be).

If DC-1 wants to replace the Shuttle, it had *better* have an access tube.

John Roberts
[e-mail]