HDTenEightyP/NetNews huggingface dataset:
From: gary@ke4zv.uucp (Gary Coffman)
Newsgroups: sci.space
Subject: Re: satellite costs etc.
Date: 31 Dec 92 00:41:06 GMT
Reply-To: gary@ke4zv.UUCP (Gary Coffman)
Organization: Destructive Testing Systems

In article <1992Dec27.202714.20889@iti.org> aws@iti.org (Allen W. Sherzer) writes:
>In article <1992Dec27.163935.20473@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes:
>
>>I wasn't aware that DC was planned to have a GEO capability, or a large
>>enough cargo bay to retrieve a major comsat.
>
>Why do you always limit your thinking so Gary? First of all, the DC-Y
>payload bay is almost the same size as Atlas. A production DC would have
>a payload bay of whatever size the market needs. Second of all, you aren't
>thinking of how lower costs will affect operations. Maybe a modified
>DC-1 is used as an OTV to get payloads where they are returned to LEO for
>repair (and not brought back to Earth). Maybe you use lower costs to fly
>redundant satellites, each less relaible. When one breaks, it uses a
>high efficiency electric engine to come back to LEO where it is repaired,
>refueled, and returned. Maybe we abandon comsats in GEO and place them in
>LEO. I can think of lots of alternatives.

I can too, but they all cost money and require developments beyond
a simple SSTO to LEO. Without costing them out, including them in
SSTO mission cost profiles against more conventional systems is bogus.
Without costing them out, there is no assurance at all that they will
lower systems costs. It's like saying that a Pinto is cheaper to develop,
buy, and operate than a unit train so we should deliver coal to power 
plants in the trunks of millions of Pintos.

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
From: Bruce_Dunn@mindlink.bc.ca (Bruce Dunn)
Subject: Re: Aluminum as rocket fuel?
Organization: MIND LINK! - British Columbia, Canada
Date: Thu, 31 Dec 1992 20:09:09 GMT

> Nick Janow writes:
> Pumping is simple, since aluminum is highly conductive.  Just use
> electromagnetic fields to thrust it through a pipe.  There's no moving
> parts
> to worry about.  I think this is being used in sodium reactor research, so
> it
> isn't an untested technology.


        I think the fundamental problem with this is where to get the large
amounts of power needed.  Even moderate sized rocket engines use turbopumps
generating several thousand kilowatts of power.

        Paul Deitz has pointed out in E-mail to me that molten aluminum would
be an ideal candidate for pressure feeding.  Relative to normal fuels such as
hydrogen (density 70 kg/m^3) and RP-1 (density 800 kg/m^3), aluminum with a
density of about 2700 kg/m^3 will require small tanks.  The tanks are very
hot, meaning that little mass of pressurization gas will be needed.  A useful
technique might be to have the molten aluminum stored in a spherical steel
tank pressurized by injecting liquid nitrogen into the tank (which because of
the heat will immediately vaporize).  Is nitrogen available from the moon?



--
Bruce Dunn    Vancouver, Canada   Bruce_Dunn@mindlink.bc.ca
Newsgroups: sci.space
From: Nick_Janow@mindlink.bc.ca (Nick Janow)
Subject: Re: Aluminum as rocket fuel?
Organization: MIND LINK! - British Columbia, Canada
Date: Wed, 30 Dec 1992 06:56:04 GMT

roberts@cmr.ncsl.nist.gov (John Roberts) writes:

> For final injection, it occurs to me that using gaseous oxygen to "blow"
> the powdered aluminum in might be an option.

That might work.  The aluminum could be formed as microfine droplets, and
then coated with another material to protect it from the oxygen until it
reaches the high-temperature reaction area.

What are the problems with using molten aluminum sprayed into the reaction
area?  Keeping the aluminum molten in a vacuum should be relatively easy.

--

Nick_Janow@mindlink.bc.ca
Newsgroups: sci.space
From: ewright@convex.com (Edward V. Wright)
Subject: Re: Terminal Velocity of DCX? (was Re: Shuttle ...)
Date: Tue, 22 Dec 1992 21:40:24 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 <1992Dec20.195520.3587@ke4zv.uucp> gary@ke4zv.uucp (Gary Coffman) writes:

>I hope the DC program all works and we get cheap and frequent access
>to LEO, but I don't think it'll operate at airliner costs or schedules,

Gary, 50 years ago you would've been telling us that jet aircraft
will never at what you now blithely dismiss as "airliner costs and
schedules."  Hundreds of flights a day in and out of Dallas-Fort 
Worth?  Planes carrying hundreds of passengers each?  Ridiculous!
Do you know how much it would cost to build just one runway for a
plane like that?  A single airport would cost billions of dollars.
There just isn't that much money in aviation -- not in the whole
country. 

>It'll still be more cost effective to assemble and test
>the bulk of space payloads on the ground and boost them to orbit
>on larger capacity launchers, especially if some effort is put into
>designing a heavy lifter for low labor costs.

Just as it's more cost-effective to assemble and test
office buildings at a central factory, then ship them
to the worksite.  Especially if some effort is put into
designing a heavy freighter for low costs. ;-)
From: rbw3q@rayleigh.mech.Virginia.EDU (Brad Whitehurst)
Newsgroups: sci.space
Subject: Re: Aerospike engines/SSTO/DC-?
Date: 21 Dec 92 15:15:39 GMT
Organization: University of Virginia

In article <1992Dec20.011900.4635@titan.ksc.nasa.gov> waterman@titan.ksc.nasa.gov writes:
>On the subject of DC-? , SSTO and Aerospike Engines the following
>observation could be made to the question Why Aerospike Engines
>are not used.
>
>Lets make an assumtion here that the military has a super secret
>spy plan (Aurora?) that can go (atleast) mach 8 to 10.  
>An engine such as this would need to be built to support a SSTO
>vehicle. The military could not have some non classified project
>stumble on their working design. What then is the goal of the
>military as it comes to SSTO research?
>
>The military will oversee the research in this area. Any designs
>which could work (or would lead to the program developing the
>same engine) will be discouraged or lobbied as non workable
>designs. In short the objectives of the military is to assure
>that this country does not have a working civilian SSTO craft.
>
>or atleast thats how I see it
>
>Bob
>
	Actually, right conspiracy theory, wrong engine! :-)
	IF there is an Aurora (decent bet), there's no reason for it
to be powered by an aerospike rocket.  It is almost certainly an
airbreathing engine.  The two most likely candidates are either a
pulsed detonation wave engine (PDWE--the "doughnut on a rope"
contrail) or a SCRAMjet, in combination with a turbine engine to get
it up and going.  The likelihood of it being a SSTO is slim--at Mach
5-8, it can get anywhere it wants in a hell of a hurry, and it'll be
plenty high--certainly (?) over 100,000 feet.  I'd bet that they've
flown both kinds of engines, and may use some sort of variable-cycle
engine.  Lastly, while I doubt that there would be an active
conspiracy to suppress SCRAMjet/aerospike/SSTO research--Congress does
a good enough job anyway--it is disappointing that there is a
potential research bonanza squirrelled away while we're spending more
$$$$$ reinventing the wheel.  Hopefully, it will be a better wheel!
-- 

Brad Whitehurst    |   Aerospace Research Lab
rbw3q@Virginia.EDU |   We like it hot...and fast.
From: prb@access.digex.com (Pat)
Newsgroups: sci.space
Subject: Re: Let's be more specific (was: Stupid Shut Cost arguements)
Date: 1 Jan 1993 23:56:42 GMT
Organization: UDSI
NNTP-Posting-Host: access.digex.com

In article <1993Jan1.030602.21051@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes:
>
>If DC flies with anything like the performance and costs that are
>projected, it will be a big commercial success. I think those 
>numbers are still optimistic and that the program risks are still
>large, however. Shuttle was a cheap $300 a pound launcher when it
>was a paper airplane too. Even with a 3X stretchout of development time, 
>and a 3X increase in projected costs, it'll beat government run Shuttle
>costs, but would have trouble against actual Shuttle costs if Shuttle 
>were run under comparable commercial rules. What I'm saying in a nutshell 
>is that the proposed DC is expected to be cheaper than the operating Shuttle 
>because they are required to operate in different manners by law and by 
>government and corporate culture.  Thus your Shuttle bashing rightfully 
>should be government operating methods bashing. I'll happily join you in 
>*that*. Government can't do anything as efficiently as the private sector.
>



Gary,

	The operating methods of any stackable vehicle are going to
	significantly different from a recoverable single stage vehicle.

	You keep arguing that the russians have high costs for their
	stackables, and that ariane has high costs subsidized by the government.

	I know you believe that cheap stackables can be done,  but those
	are the same paper designs you condemn DC for.  

	Shuttle could have lower costs then  NASA currently has,
	but it still needs a tremendous infrastructure.  The OPF,
	the VAB, Tilting bay,  the crawler/transporter.  Launch towers.

	The DC  will not need much more infrastructure, then a 
	airline hangar.  Henry, alan and I all believe that eliminating
	all this structure and cost  will make up for any lower
	vehicle lift capacity.  

	Please demonstrate how Lockheed could eliminate all these costs
	from commercial shuttle operations.

pat
Newsgroups: sci.space
From: aws@iti.org (Allen W. Sherzer)
Subject: Re: SSTO vs 2 stage
Organization: Evil Geniuses for a Better Tomorrow
Distribution: sci
Date: Thu, 31 Dec 1992 18:28:43 GMT

In article <ewright.725820847@convex.convex.com> ewright@convex.com (Edward V. Wright) writes:

>Now, please point out to me where my analogy is flawed.

I do't think it is flawed so much as missing the point. The point is to
reduce the cost of access to LEO. Bruce's ideas to me seem well thought out
and practical. It cuts costs and reduces risk which is all that matters.

I agree with you that SSTO will eventually be the solution (at least the
way it looks now). That doesn't preclude other options which cut costs and
reduce risk as stepping stones leading in that direction.

    Allen

-- 
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  aws@iti.org     |  nothing undone"                                       |
+----------------------114 DAYS TO FIRST FLIGHT OF DCX----------------------+
Newsgroups: sci.space
From: sbooth@lonestar.utsa.edu (Simon E. Booth)
Subject: Re: Apollo 13 book
Organization: University of Texas at San Antonio
Date: Mon, 21 Dec 1992 09:23:01 GMT


There's a book called 'Thirteen: The Flight That Failed" but I forgot the name
of the author.

Simon

Newsgroups: sci.space
From: ewright@convex.com (Edward V. Wright)
Subject: Re: Comparative $/lb to LEO (Was: Stupid Shuttle Cost Arguments)
Date: Wed, 30 Dec 1992 17:24:16 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 <C01E43.JIJ@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes:

>It's somewhat more common for the shuttle [to fly with less than maximum
>payload] only because most shuttle missions are to low orbit

Don't forget the Rogers Commission, and the payload-weight restrictions
it imposed for safety reasons.
From: n4hy@wahoo.UUCP (Bob McGwier)
Newsgroups: sci.space
Subject: Re: cryptocraft photography, Re: Aurora
Date: 21 Dec 92 17:02:46 GMT
	<1go2tvINNhlj@uwm.edu> <1992Dec17.040911.15524@mnemosyne.cs.du.edu>
	<1992Dec19.005254.1@stsci.edu>
Distribution: sci,na
Organization: IDA Center for Communications Research
In-reply-to: hathaway@stsci.edu's message of 19 Dec 92 05:52:54 GMT

>  Identification: It had all the familiar steady motion of an 
>                  Earth satellite, but _not_ in a common Direct orbit from 
>                  West to East.  Motion actually more like from NE by N to 
>                  SW by S.  If a satellite, it was in a near-polar orbit, but 
>                  Retrograde.  



From NE by N down to SW by S is <NOT> retrograde.  This is the descending
half of a normal orbit with inclination less than ninety degrees.  Remember
that in June, the north pole is in continuous sunlight.  We could figure out
the EXACT height from your observations since we KNOW where the satellite
will enter the `umbra' of its eclipse given by your observations.  If I have
time, I will do this computation if not, given this someone else should be
able to do the simple calculation.

BMc

Newsgroups: sci.space
From: shafer@rigel.dfrf.nasa.gov (Mary Shafer)
Subject: Re: Aurora
Organization: NASA Dryden, Edwards, Cal.
Distribution: sci
Date: Tue, 22 Dec 1992 15:47:36 GMT

On 22 Dec 92 14:54:42 GMT, PHARABOD@FRCPN11.IN2P3.FR said:

JP> In answer to John Roberts (Tue, 22 Dec 92 00:27:14 EST):

>I suspect the misunderstanding is due to one of those words that's
>nearly the same in two languages, but which has slightly different
>connotation. Doesn't the French verb "chasser" mean "to hunt"?

JP> Yes, "chasser" means "to hunt", and it is very agressive. What we
JP> call an "avion de chasse" is what you call a "fighter". According
JP> to the dictionary, "to chase" seems indeed a little less agressive,
JP> and may be translated by "chasser" but also by "poursuivre" (= "to
JP> pursue"), so there is some ambiguity.
JP> However, a F-16 is a fighter, and I still find a little disturbing
JP> that US fighters chase US "deep black" planes.

Traditionally, we have always chased high, fast aircraft with
high-performance aircraft (fighters).  Here at Dryden, we've used
F-104s, T-38s, F-18s, F-100s, T-33s, and other high-performance
aircraft.  

High-performance aircraft have the best flight envelope to stay with
the test plane if it's got any kind of envelope at all.  Plus, they're
mature technology, so your chase won't break and cancel the mission.
(Well, not often--we had a problem yesterday with the second flight of
the HARV, when the chase F-18 had a problem on the ramp and the HARV
had to hold until they got the chase fixed, but it only took twenty
minutes or so.)

After all, the French chased Concorde with Mirages.

I don't understand why you find this "disturbing".  The chase planes
don't carry missiles or anything; they just fly safety chase.  They're
not there to shoot down the test airplane or launch missiles at
traffic.  They're just there if there's a problem.  They take the
radio calls, watch the position in the restricted area, look for
traffic, and keep an eye on the test plane for things like leaks.  We
had a USAF chase pilot in an F-4 catch a hydraulic leak in the
AFTI/F-111 very early.  The AFTI/F-111 RTBed immediately and ran out
of hydraulic pressure on the taxiway; we may well have lost the test
aircraft if chase hadn't noticed the thin stream of fluid\ coming off
the plane.

Perhaps you're confused by the fact that high-performance aircraft are
designated as fighters?  Many of these aircraft are dedicated to the
chase role; the USAF's T-38 pacers (used for airspeed and altitude
calibrations) are a good example.

What were you planning on chasing a supersonic/hypersonic plane with?
A Cessna 172?  We chased our hypersonic airplane, the X-15, with
F-104s.
--
Mary Shafer  DoD #0362 KotFR NASA Dryden Flight Research Facility, Edwards, CA
shafer@rigel.dfrf.nasa.gov                    Of course I don't speak for NASA
 "A MiG at your six is better than no MiG at all."  Unknown US fighter pilot
Newsgroups: sci.space
From: roberts@cmr.ncsl.nist.gov (John Roberts)
Subject: Re: Asteroids, minor planets
X-Added: Forwarded by Space Digest
Organization: National Institute of Standards and Technology formerly National Bureau of Standards
Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU
Distribution: sci
Date: Thu, 24 Dec 1992 04:58:50 GMT


-From: billn@hpcvaac.cv.hp.com (bill nelson)
-Subject: Re: asteroids beyond Jupiter
-Date: 23 Dec 92 20:35:36 GMT
-Organization: Hewlett-Packard Company, Corvallis, Oregon USA

-gwc@csd4.csd.uwm.edu (Greg F Walz Chojnacki) writes:
-: 
-: Although it might seem like I'm paying out rope here, I'm curious about the
-: usage of the terms "asteroid" and "planetoid." Bill, since yours is the first
-: time I saw the distinction made, care to define these? (I hope it's more than
-: asteroids being those things that lie where asteroids were first discovered.)

-Nope, that is the distinction I use. Whether it is currently the accepted
-definition is another matter. I define an asteroid to be a body that 
-originated in the asteroid belt - others are planetoids or "minor bodies"
-or comets etc.

"Of the many thousands of minor planets, the vast majority appear 
telescopically like stars - that is, as small points of light. The term
*asteroid* (meaning "starlike") is therefore often applied to these tiny
worlds. Another synonym is *planetoid*. The term *minor planet*, preferred
by the International Astronomical Union, is used in this text."

 from "Exploration of the Universe", by George O. Abell, C. 1964, 1969, 1975.

Actually, I prefer the term *asteroid*. You're welcome to set your own
definition, then point out that the only things that fit your definition
are the things that fit your definition, but I don't know how useful
such a statement is. :-)

There is evidence that some of the things we call asteroids used to be
comets.

John Roberts
roberts@cmr.ncsl.nist.gov
From: dietz@cs.rochester.edu (Paul Dietz)
Subject: Re: Breeder reactors
Followup-To: sci.energy
Organization: University of Rochester
Distribution: sci
Date: Tue, 22 Dec 1992 15:29:34 GMT

In article <BznFpx.93v.1@cs.cmu.edu> roberts@cmr.ncsl.nist.gov (John Roberts) writes:

> One concern I've heard concerning at least some of the breeder cycles is that
> the fuel produced is more easily converted to bomb-grade material than is the
> U238-U235 mix traditionally used in commercial reactors. At the moment, it's
> difficult to guarantee that nobody can steal or divert a sufficient quantity
> of such a material (if it's widely used) to cause trouble. I believe I've
> heard proposals such as deliberately contaminating the fuel with high-level
> waste to make it too dangerous for thieves to handle. Do you have any more
> information on this aspect? And are there designs where the breeder itself
> consumes the fuel it generates?

(I've redirected followups to sci.energy.)

Let me preface this by observing that in a world where countries are
getting richer and more productive, the only long term way to keep
countries from making bombs is to have them not want to make bombs.
This is true even if our energy sources are non-nuclear.  Nuclear
terrorism, I think, is overrated; chemical terrorism is much easier,
after all, and as deadly, but has not yet occured.

There are nuclear fuel cycles that make the fuel less easily diverted
(although none is completely safe.)  The pyrometallurgical process for
reprocessing spent fuel developed at ANL leaves the reprocessed
actinides contaminated with sufficient high level waste to make
diverting them difficult.  This process is pretty simple (just 3 or 4
basic steps) and could be done on-site.

Thorium-based cycles would make U-233.  This could be spiked
with U-232, which would make the fuel a fairly strong gamma emitter.
This would make its diversion difficult and easily detectable.

Since this discussion was in the context of space resources, do
remember that to make a significant impact on terrestrial resource
demands, space industry would involve the manipulation of billions of
tons of material per year.  A 60,000 ton object dropped on the earth
hits with a yield of at least a megaton.

	Paul F. Dietz
	dietz@cs.rochester.edu
From: lindsay+@cs.cmu.edu (Donald Lindsay)
Newsgroups: sci.space
Subject: Re: Stupid Shut Cost arguements
Date: 28 Dec 92 22:35:35 GMT
Article-I.D.: cs.BzzqrC.3BK.2
Organization: School of Computer Science, Carnegie Mellon


aws@iti.org (Allen W. Sherzer) writes:
>Can you name a product ever made by a successful company which DIDN'T
>keep track of product development costs (as opposed to pure research)
>and assign those costs to the product? Outside government, you won't.

Hmmm. I remember hearing that Xerox bought SDS for a billion dollars
- this would be about 1970. I heard later that Xerox had paid about
twice what it was worth. Apparently SDS had been taking R&D costs and
writing them into the books as assets, ie as if it had purchased
capital equipment with the money.
-- 
Don		D.C.Lindsay	Carnegie Mellon Computer Science
From: kirby@xerox.com (Mike Kirby)
Newsgroups: sci.space
Subject: Re: Justification for the Space Program
Date: 29 Dec 92 21:01:29 GMT
Reply-To: kirby@xerox.com
Organization: Xerox Corporation, Webster NY

In article 13239@cs.rochester.edu, dietz@cs.rochester.edu (Paul Dietz) writes:
>In article <JMC.92Dec28192905@SAIL.Stanford.EDU> jmc@cs.Stanford.EDU writes:
>
>> Let me add to the previous post the estimate that the total amount of
>> matter humanity has processed in its history is less than 10^12 tons.
>
>Some interesting facts:
>
>Estimated mass of manganese nodules on the ocean floors:  ~ 10^12 tons.
>
>Average concentration of metals in nodules (percent)
>
>	Element		World Average	Pacific Clarion-Clipperton Zone
>	--------------------------------------------------------------
>	  Mn		   18.6			25.4
>	  Fe		   12.47		 6.66
>	  Ni		     .66		 1.27
>	  Cu		     .45		 (not listed, > .45)
>	  Co		     .27		 1.02
>
>
>World-wide, nodules are estimated to contain billions of tons of
>copper and nickel, and enough manganese to supply current mine demand
>for that element for roughly 10,000 years.  Additional sources of
>metals (such as copper and cobalt) are available as crusts on the sea
>floor, and in massive sulfides deposited at mid-ocean ridges and then
>carried away by plate motion.
>
>	Paul F. Dietz
>	dietz@cs.rochester.edu


This is great except that companies are limited to mining only nodules that
occur withing their territorial waters.  All other nodules are considered
"property of the earth" and are to be shared by all nations equally.  Needless
to say this removes much of the profit motive for sea bed mining.

There is a U.N. Treaty that covers undersea resources. (with the possible exception
of oil).  Does anyone know what the treaty precisely says?

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