HDTenEightyP/NetNews huggingface dataset:
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: satellite costs etc.
Date: Wed, 23 Dec 1992 20:35:51 GMT
Organization: U of Toronto Zoology

In article <1992Dec23.111923.22269@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes:
>... A ten year life zero defects
>GEO comsat like K2 is much cheaper than a 1 year life package
>that costs 20 times less. That's because most of the investment is
>not in the satellite, it's in the Earth based terminals that use it.

I don't grasp this argument.  It's the same Earth-based terminals either way.
If you're providing a service, you plan to do so over more than one satellite
lifetime, either way.  Twenty years of service is cheaper with mass-produced
short-life satellites, even with your (fairly unfavorable) assumptions.

>... Since the satellite represents a single point failure node...

This is your assumption, not a self-evident fact.  Communications networks
normally have redundancy to cover predictable single-point failures.
Even today's gold-plated satellite networks do, despite the expense.

>... and since for most orbits
>the satellites aren't retrievable or repairable, and DC won't change
>that...

Again, your assumption, not a self-evident fact.  Cheap launches change
almost everything, including the feasibility of retrieval and repair.
-- 
"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
       -Gene Cernan, the Moon, Dec 1972 |  henry@zoo.toronto.edu  utzoo!henry
Newsgroups: sci.space
From: ewright@convex.com (Edward V. Wright)
Subject: Re: aerospikes
Date: Wed, 23 Dec 1992 19:59:12 GMT
Organization: Engineering, CONVEX Computer Corp., Richardson, Tx., USA
X-Disclaimer: This message was written by a user at CONVEX Computer
              Corp. The opinions expressed are those of the user and
              not necessarily those of CONVEX.

In <1992Dec21.193604.28757@eng.umd.edu> sysmgr@king.eng.umd.edu (Doug Mohney) writes:

>Contrast this with one (or more) flights out of Nevada or White Sands which may
>or may not be significant (helps if you've been running up and back to LEO for
>a while as a regular habit) and kicking out the sat on one of those runs. 

Well, if they (whoever "they are") don't know your flight is "significant"
enough to shoot down, why are you in a hurry to reenter?


>The cheap-sat may be in a predictable orbit, but you are now faced with
>detecting it without the benefit of CNN coverage. 

If they can't detect a cheapsat without CNN coverage, how can they detect 
the launch vehicle?  


>Now, unless you have information from umm.. SPACETRACK? in NORAD, you have to
>pick cheap-sat out of all the other man-made objects in orbit via some optical
>means (hope it's not a cloudy night, but that cuts both ways) or with radar.

Anyone who has an operational ASAT must, by definition, have some means
of targeting.


Newsgroups: sci.space,talk.politics.space
From: DRPORTER@SUVM.SYR.EDU (Brad Porter)
Subject: University standards (esp. Purdue)
Organization: Syracuse University
Date: Sat, 26 Dec 92 22:45:15 EST

In article <Bztt8t.9L8@mentor.cc.purdue.edu>
hrubin@pop.stat.purdue.edu (Herman Rubin) writes:
 
>The
>universities are giving in to the almost illiterate (at least in
>mathematics and the sciences) high school preparation of the students,
>and contributing to the demise of our academic and research capabilities.
I'm digressing a bit, but I felt I had to respond to this statement by
asking if you truly believe this?  Do you believe that's true of all public
schools, or just the schools in Indian, from which the majority of Purdue's
students come?  I tend to feel it's the univerity's standards that are lower,
not those of the public schools.  If the professors at Purdue have this
low of an opinion of the students, I'm going to have to reconsider Purdue
as a possible school for me (I've been accepted into Freshman Engineering).
                              -Brad Porter
Skaneateles, New York
DRPORTER@SUVM
Newsgroups: sci.space
From: aws@iti.org (Allen W. Sherzer)
Subject: Re: Why have both manned and auto capability on DC-[XY1] & Buran?
Organization: Evil Geniuses for a Better Tomorrow
Date: Tue, 22 Dec 1992 16:24:36 GMT

In article <1992Dec18.011309.12639@bby.com.au> gnb@baby.bby.com.au (Gregory N. Bond) writes:

>Given that the thing can fly automatically, why add pilots?

For the exact same reason airliners (which can also fly automatically)
have pilots: to deal with emergency situations.

  Allen

-- 
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  aws@iti.org     |  nothing undone"                                       |
+----------------------123 DAYS TO FIRST FLIGHT OF DCX----------------------+
From: gary@ke4zv.uucp (Gary Coffman)
Newsgroups: sci.space
Subject: Re: Latest Pegasus news?
Date: 27 Dec 92 16:42:47 GMT
Reply-To: gary@ke4zv.UUCP (Gary Coffman)
Organization: Destructive Testing Systems

In article <BzqMxr.MuH@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes:
>In article <1992Dec23.201155.29373@microsoft.com> steveha@microsoft.com (Steve Hastings) writes:
>>What are the Pegasus folks up to right now?
>
>The third launch is slated for January.  If that works out okay, they hope
>to ramp things up very quickly in 1993.  There's a backlog of payloads
>waiting for the second-launch problems to be solved.
>
>(Yes, problems plural:  apparently they had both a first/second-stage
>separation problem, and a fairing-separation problem.)  (Yet more proof
>that God did not mean us to build rockets that shed parts on the way up. :-))

And to think, it was only last year that Pegasus was the net's darling
that was going to bring the cost of space travel down to nil. These
bandwagons are not only crowded, they also seem to be short lived. It's
funny that the flaws only show up when something actually flies.

Gary

-- 
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary      
Lawrenceville, GA 30244     |                     | emory!ke4zv!gary@gatech.edu
Xref: sparky sci.space:18512 talk.politics.space:1653
From: dietz@cs.rochester.edu (Paul Dietz)
Newsgroups: sci.space,talk.politics.space
Subject: Public support for the space program
Date: 31 Dec 92 18:46:56 GMT
Organization: University of Rochester

In article <1992Dec30.230013.4102@aio.jsc.nasa.gov> Dr. Norman J. LaFave <lafave@ial4.jsc.nasa.gov> writes:

>> The *relative* support of the space program is not very high.

> Another Dietz assertion-without-proof... Please
> provide data which shows the relative support.


Okay!

From Gallup Report #289, October 1989, pages 4-10.

This poll asked 1,234 Americans what categories of public spending
they would like to see increased.  The results:

	Education			76%
	Drugs				75
	Homeless			71
	Health Care			67
	Pollution			59
	AIDS				59
	Job Training & Placement	56
	Help low-income families	56
	Aid farmers			48
	Health insurance		48
	Aid college students		44
	Child care services		41
	First-time home buyers		37
	Space exploration		21
	Defense spending		17

When a subgroup was asked if they were willing to pay additional taxes
to increase federal spending for an item, suport for space exploration
was also next to last, at 13% (the top 4 categories in the list
remained above 50%).

Another poll conducted July 1990 (The Gallup Poll Monthly, Sept. 1990,
pages 44-45) showed a decline in support for the space program.
In response to the question

   "On the whole, do you feel our investment
   in space research is worthwhile or do you think it would be better
   spent on domestic programs such as health care and education?",

the response was:

	Year		Worthwhile	Domestic	No opinion
	1989		   43%		  52		  5
	1990		   39		  57		  4

In response to the question

  "I am going to ask you a question about government spending.
   In answering, please bear in mind that sooner or later all
   government spending has to be taken out of the taxes that you
   and other Americans pay.  Thinking about the US space program,
   tell me whether the amount of money now being spent for that purpose
   should be increased, kept at the present level, reduced, or ended
   altogether?"

	Year		Increase       Same   Reduce   End    No Opinion
	1984		   21%		48	23	5	3
	1986		   26		50	14	5	5
	1989		   27		42	22	4	5
	1990		   17		37	32     10	4

I imagine the jump in 1986 was a result of the Challenger disaster.

The polling data does show that the public favors manned (48%) over
unmanned (34%) programs.

	Paul F. Dietz
	dietz@cs.rochester.edu
Newsgroups: sci.space
From: mccreary@sword.eng.hou.compaq.com (Ed McCreary)
Subject: Re: Sea floor Planetary Protection really.
Organization: Compaq Computer Corp.
Distribution: sci
Date: Thu, 31 Dec 1992 20:48:38 GMT

In article <1hvg8sINNppt@mirror.digex.com> prb@access.digex.com (Pat) writes:
>NASA  has adopted the COSPAR guidelines on planetary protection and i believe
>even has an office for this.  They are concerned about contamination in
>both ways.  They reccomend, heat sterilization, radiation,  gas and chemicals.
>
>The big concern now is not so much establishing earth organisms on foreign
>bodies, but destroyin/contaminating archaeology studies of exo-biology.
>
>I know the Mars Observer orbit was constrained under planetary protection
>guidelines to stay off the surface for X thousand years.

True.  After it's mission is finished, MO will be raised to a high
enough orbit to prevent it's re-entry for X thousand years.

On a related note, the designers of Viking were worried that
the Soviets would land a probe on Mars before their landing without
following strict sterilization procedures.  This, they felt, might
contaminate Viking's biological results.  Luckily, the soviets decided
to follow similar guidlines. 

--
Ed McCreary                                               ,__o
mccreary@sword.eng.hou.compaq.com                       _-\_<,
"If it were not for laughter, there would be no Tao."  (*)/'(*)
Newsgroups: sci.space
From: kirby@xerox.com (Mike Kirby)
Subject: Re: Justification for the Space Program
Reply-To: kirby.roch803@xerox.com
Organization: Xerox Corporation, Webster NY
Date: Mon, 28 Dec 1992 19:09:41 GMT

In article 1305@cs.rochester.edu, dietz@cs.rochester.edu (Paul Dietz) writes:
>In article <1992Dec28.152258.23834@aio.jsc.nasa.gov> Dr. Norman J. LaFave <lafave@ial4.jsc.nasa.gov> writes:
>>In article <1992Dec27.205945.25241@cs.rochester.edu> Paul Dietz,
>>dietz@cs.rochester.edu writes:
>
>
>The differences between the age of exploration and today are
>considerable.  The raw mineral and agricultural products (and slaves)
>that profited the explorers of that age are a much smaller fraction of
>GDPs today.
>
>More generally, arguments by analogy are essentially circular.  You
>have to assume that the analogy is valid to believe the argument.  I
>don't see any reason to do that here.  There are contrary analogies:
>for example, exploration of Antarctica has been of little practical
>benefit to the exploring countries (although it has been of scientific
>benefit to humanity as a whole).
>
>	Paul F. Dietz
>	dietz@cs.rochester.edu


It seems that a reasonable justification for space exploration is simply that.
It is there.  Your analogy of Antarctica is very relevant.  Although it has not
been a great financial success, it has been of scientific benefit.

By that same argument exploration of space could give us the same scientific benifit.

Similarly, exploration of the deep seas is of little economic benifit, but scientifically it allows us to learn more about our planet.

So.  The original question was should we spend tax-payer money to explore space.  I 
think paul has given us the answer.  That answer is yes.  We can spend taxpayer money
to explore for scientific research.  However, taxpayer money should not be spent
to help to government extract economic advantages from space.  (which is reasonable,
that is what private industry is supposed to do).

Perhaps we should form a government agency that is responsible for the development
and exploration of the scientific aspects of space.  Gasp, Could that be NASA?
But aren't they a commercial satellite launch company?  

In all seriousness, it does seem that NASA has strayed a little from what their
charter was originally intended to provide.  Perhaps a manned space station is a 
good thing to have, but its sole purpose should be technical innovation and research
and development.  Not Economic development.

Mike Kirby
Xerox Corp
E-mail: kirby.roch803@xerox.com


Newsgroups: sci.space
From: BrianT@cup.portal.com (Brian Stuart Thorn)
Newsgroups: sci.space
Subject: Re: How many flights are Orbiters designed for?
Date: Fri,  1 Jan 93 17:03:34 PST
Organization: The Portal System (TM)
  <neff.14.725817375@iaiowa.physics.uiowa.edu>
  <ewright.725822222@convex.convex.com>

>In <neff.14.725817375@iaiowa.physics.uiowa.edu> neff@iaiowa.physics.uiowa.edu 
(
>John S. Neff) writes:
>
>>I recall an estimate of 50 flights by a NASA spokesman.
>
>The politically (but not necessarily technically) correct line
>is now that "the Shuttle orbiters will last for longer than their
>original 100-mission design life."
>

   That came from the Rockwell engineers who upgraded Columbia in
   1991-1992. Columbia is the oldest and second-most-flown Shuttle
   and they said there was no reason from an engineering standpoint
   that the Shuttle could not fly 100 or more missions.
   
   Keep in mind that the Shuttles have been down for heavy maintenance
   twice in the eleven year history of the program: 1986-88 and
   1991-1993 (with each Orbiter being down six to nine months at some
   point in this period.)
   
   Hopefully, we'll have a DC-1 or better system to replace Shuttle
   long before any hits one hundred missions.
   
   -Brian
  

-------------------------------------------------------------------------
Brian S. Thorn                                    "If ignorance is bliss,
BrianT@cup.portal.com                               this must be heaven."
                                                -Diane Chambers, "Cheers"
-------------------------------------------------------------------------
From: MUNIZB%RWTMS2.decnet@rockwell.com ("RWTMS2::MUNIZB")
Newsgroups: sci.space
Subject: Aerospike Engines... what are they?
Date: 2 Jan 93 22:37:23 GMT
Distribution: sci
Organization: [via International Space University]
X-Added: Forwarded by Space Digest
Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU

On Date: Fri,  1 Jan 93 17:02:56 PST, Brian Stuart Thorn <BrianT@cup.
portal.com> writes:
>   Much has been said recently about aerospike engines, specifically
>   in regard to potential use on the DC-1. I've never heard of them
>   before, can someone give me (and anyone else in the dark) a brief
>   description of what an Aerospike Engine is?
 
Briefly, an aerospike engine uses an exhaust nozzle that can be thought
of as a conventional bell shaped nozzle turned inside-out.  The aerospike 
nozzle is a truncated version of an ideal spike;

       Bell           Ideal Spike           Aerospike

       ||||         |------------|       |------------|
      /    \         \          /         \          /
    /        \        \        /           \        /
  /            \       \      /             \______/
                        \    /
                         \  /
                          \/         

                               (| indicates the combustion location).

In a bell nozzle combustion gas flow expands outward from the centerline 
along the diverging walls.  This is a point design with optimum 
performance at one specific ambient pressure (altitude).  Careful design 
is needed to achieve desired high altitude performance while avoiding 
flow separation at low altitudes which can result in structural damage.  
Movable nozzle extentions can provide altitude compensation (larger 
exit/throat area ratio at higher altitudes) to overcome some of the 
compromise in design.

In an spike nozzle the opposite takes place and the gas flow is directed 
inward from an annulus at some diameter away from the centerline.  This 
flow is directly exposed to ambient pressure and its expansion is thus 
directly coupled to the external environment (continuous altitude 
compensation with no moving parts).  Truncating the ideal spike to save 
weight results in a bubble of flow at the base which has some performance 
loss.  This can be offset by pumping secondary flow (about 1% of primary) 
into the base region to elongate the bubble which then forms an 
aerodynamic countour similar to the truncated structure (hence the name 
"aerospike").

In an earlier post I discussed Rocketdyne's testing of aerospike engines 
and compared its efficiency with bell nozzles.

Disclaimer: Opinions stated are solely my own (unless I change my mind).
Ben Muniz, Rocketdyne, SSF Dynamics | "Man will not fly for fifty years"
munizb@rocket.rdyne.rockwell.com    |     Wilbur to Orville Wright, 1901
Newsgroups: sci.space
From: hack@arabia.uucp (Edmund Hack)
Subject: Re: Stupid Shut Cost arguements (was Re: Terminal Velocity of DCX?
Summary: Be careful in wording.
Organization: Lockheed ESC, Houston
Date: Tue, 29 Dec 1992 20:04:44 GMT

In article <ewright.725647230@convex.convex.com> ewright@convex.com (Edward V. Wright) writes:
>In <1992Dec28.172953.26161@ke4zv.uucp> gary@ke4zv.uucp (Gary Coffman) writes:
>
>>Shuttle's costs were all accounted for too. The customer, the US
>>taxpayer, wanted R&D done to develop a reusable spacecraft. NASA
>>did it, and that public domain database of technologies is what
>>the taxpayer got for his money, not bent metal. 

[flamage deleted]
> 
>Furthermore, you are wrong in stating that the information is
>in the public domain.  It is the property of the United States
>Government.  Any taxpayer who wants to use this information has
>to pay (again) for the privilege.

How do they have to pay except for copying costs?  Certain parts of the
shuttle design may be either classified (i.e. the comm crypto gear) or
proprietary (some of the COTS equipment), but the bulk is available for
copying costs.  If I want a copy of the schematics, I find a copying
cost charge reasonable.
>
>>NASA is not supposed to be in the fabrication business.
>
>You're right.  So why do you support NASA being in a business
>that it is illegal for them to be in?
            ^^^^^^^
Please cite the _exact_ basis for this statement, i.e. the part of the
U.S. Code or the appropriations laws that make it illegal to fabricate
things.  Either that or be more careful in your flaming.  Accusing NASA
of illegal acts without basis is impolite at the minimum.

Also, this thread has gone about as far as it can go.  Please save
bandwidth and disk wear and tear and _drop it_.  Please.

-- 
Edmund Hack - Lockheed Engineering & Sciences Co. - Houston, TX
hack@aio.jsc.nasa.gov - I speak only for myself, unless blah, blah..
"You know, I think we're all Bozos on this bus."
"Detail Dress Circuits" "Belt: Above A, Below B" "Close B ClothesMode"
Newsgroups: sci.space
From: polish@cs.columbia.edu (Nathaniel Polish)
Subject: Re: Biosphere 2 update
Organization: Columbia University Department of Computer Science
Distribution: sci
Date: Tue, 22 Dec 1992 16:07:12 GMT

I realize that there has been much debate concerning the seriousness of the
science of Biosphere 2.  However the problems posed are still fascinating.
If indeed this is to be viewed as a prototype space colony then I have a 
problem with the review just posted from a crewmember.

There was much made of the wide variation in sunlight causing variation of
CO2 uptake by plants.  Further we have all seen discussions of the somewhat
uncomfortable drop in O2 level.  I would presume that any space colony would 
have a reasonably abundant source of electric power (nuke or solor collectors).
This renders the issue of variable sunlight level moot as light is one thing
that we can easily create.  Also, one would not expect the sunlight levels 
in Tuscon to be available on other planets.  So the real question is: to what
extent are the questions asked and circumstances created intended as a space
colony prototype?

Obviously, a Biosphere 2 crewmember would be the ideal respondant.

Thanks


Newsgroups: sci.space
From: jmc@SAIL.Stanford.EDU (John McCarthy)
Subject: Re: Stupid Shut Cost arguements (was Re: Terminal Velocity
Reply-To: jmc@cs.Stanford.EDU
Organization: Computer Science Department, Stanford University
	<1992Dec29.191524.2413@iti.org> <72597@cup.portal.com>
Date: 29 Dec 92 22:27:37

The reason Shuttle costs are so much more than projected is that the
Shuttle requires this army to maintain it between flights.  Hydrogen
isn't much more expensive than expected, and I doubt the solid fuel
is either.  When the Shuttle was first proposed, the idea of operating
it like an airline was part of the plan from the beginning.  It
turned out that the Shuttle operated too close to the limits of the
materials and structures of which it was made.  That's why it needs
so much maintenance.

If someone proposes a new reusable vehicle for going to earth orbit,
it is reasonable to ask why its maintenance costs can be expected to
be a lot less than those of the Shuttle.  Any answer you get needs to
be evaluated skeptically.
--
John McCarthy, Computer Science Department, Stanford, CA 94305
*
He who refuses to do arithmetic is doomed to talk nonsense.

Newsgroups: sci.space
From: borden@sol.UVic.CA (Ross Borden)
Subject: LEI financing
Organization: University of Victoria, Victoria, B.C. CANADA
Date: Tue, 22 Dec 92 08:38:08 GMT

	I read the information that LEI has posted at ames.  Very interesting
stuff.  It's a worthwhile idea and should be supported.
	However, I have a problem with funding by donation.  I would be willing
to donate ~$100.  But, if I had a reasonable expectation of getting my money
back, I would be willing to invest several $1000.  I wouldn't be greedy about
it either.  I would be satisfied to get the principle back at the end of the
mission.  Call it a 3-4 year no interest loan.
	I suspect that there would be many other space enthusiasts who would
be willing to 'loan' sizable pieces of change on this basis.
	Of course, I realize that making a mission like this even a break-even
proposition is not easy.  How much thought has gone into marketing the resource
map that will be produced?  Could you talk NASA into buying the whole thing for
,say, $20M ?  (I recall a proposed bill called something like "Lunar Resources
Information Purchasing Act" by which the US government would require NASA to 
purchase the first available lunar resource map.  What happened to it?  Did it
die, or is there still a chance of passing it?)
	How about copyrighting the map and selling copies to universities,
governments etc. for $500.  (Hmmmm... $16,000,000/$500 = 32,000.  Well, maybe.)
Or even a student rate of $50 ;-)
	How about selling exclusive information from small areas to
'prospectors'?  (Yeah, you'd need pretty far-sighted prospectors.)
	The problem is the fundamental obstacle to getting all of us
out there, where we belong: not launch costs, or new technology, but
making it *pay*  Until it does, we're stuck here.

_______________________________________________________________________________
|                   .sig?  I don't need no stinking .sig!                     |
|                           rborden@ra.uvic.ca                                |
-------------------------------------------------------------------------------
Newsgroups: sci.space