HDTenEightyP/NetNews huggingface dataset:
From: ewright@convex.com (Edward V. Wright)
Newsgroups: sci.space
Subject: Re: Pilots must be stupid? (Re: DC vs Shuttle capabilities
Date: 23 Dec 92 17:02:55 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 <gjt2v-d@rpi.edu> strider@clotho.acm.rpi.edu (Greg Moore) writes:

>>You can walk from one place to another carrying a four-ton
>>cargo container?  On Earth?  I doubt it.

>	Carry it while walking? no, but I can drive it.

If you have a flat tire?

See, for every "greater difficulty" you can think of in
space, I can think of one on Earth.


>	Again, I think I see were we are differing.  See my other
>post on timeframes.  But to recap, I agree, after a couple thousand
>more hours of EVA time, we'll have a lot more down.

If the cost of putting one man into space was $50,000, instead
of $5,000,000, you'd be able to rack up a thousand man-hours
of EVA time pretty fast.


>A diver can swim back.  Or, with enough air (which they should
>always have) resurface.  

Not if they're SEALs in a combat zone.  Or cave divers.  Or
under ice.  Or working in an underground sewer system.  All 
of which are done routinely today.


>>What makes you think a DC-1 can't accomplish a hard docking.
>>
>	I wasn't aware that it could.  This I understand would
>have to be an added capability?  HOw does it dock? through the
>nose? or along the side?

The McDAC illustration shows it docked alongside.  I'm sure
the docking adapter would be an added capability, carried in
the cargo bay.  Why carry it along on flights where you don't
need it?  

If you consider this a problem, well, the Shuttle's docking
adapter works the same way.
From: juan@nuala.hal.COM (John Thompson Reynolds)
Newsgroups: sci.space
Subject: Re: Aluminum as Rocket Fuel?
Date: 30 Dec 92 15:41:48 GMT
Distribution: sci
Organization: HaL Computer Systems, Inc.


In article <C01vE9.HsF.1@cs.cmu.edu>, 0004244402@mcimail.com (Karl Dishaw) writes:
|> I dug into my notes from Aero/Astro project lab, we tried to make a 
|> fuel feeder for an aluminum/oxygen rocket:
|> 
|> Isp = 118 sec (after accounting for loss due to solid particles)
|> Must run oxidizer-rich since Al2O3 is a solid.
|> Main hazard--oxygen getting into Al storage tank.
|> 
|> I'd love to see some info on the Wickman project.  The Isp is too low to 
|> be really useful, but it would be great for circularizing orbits on mass 
|> driver-launched payloads, or maybe cheap transport on the lunar 
|> surface.

Thanks for the info.

My thoughts were along the line of constructing a hollow cylinder of
powdered aluminum, into which you would pump LOX at a controlled rate.
The Aluminum particles might need to be held in some sort of a matrix
material, both to keep them in place, and to prevent the buildup of an 
Aluminum Oxide casing.  I wonder what the effective Isp of Aluminum laced
epoxy is?

I seem to remember a somewhat similar design which pumps LOX into a tube of 
rubber?  To stop the "engine", stop the flow of LOX.

Obviously such a design would only be useful in a vacuum, and is probably
no more reusable than an SRB.

John Reynolds
Newsgroups: sci.space
From: henry@zoo.toronto.edu (Henry Spencer)
Subject: Re: SSTO vs 2 stage
Date: Sun, 3 Jan 1993 22:45:41 GMT
Organization: U of Toronto Zoology

In article <1993Jan3.104049.2581@ringer.cs.utsa.edu> sbooth@lonestar.utsa.edu (Simon E. Booth) writes:
>The idea of a 2 stage DC configuration seems technically sound, but how
>would it be compatible with the launch facilities designed around the
>intended DC-vehicle (single stage)?

It wouldn't be, basically.  It would be a special configuration for
special needs, and would require special launch facilities.

>Could the service gantries and launch pads be designed to accomodate
>different spacecraft configurations?

It can be done, but it runs up the price, so it isn't done unnecessarily.
-- 
"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
       -Gene Cernan, the Moon, Dec 1972 |  henry@zoo.toronto.edu  utzoo!henry
From: gary@ke4zv.uucp (Gary Coffman)
Newsgroups: sci.space
Subject: Re: GEO satellites as electrical vehicles
Date: 31 Dec 92 01:00:09 GMT
Reply-To: gary@ke4zv.UUCP (Gary Coffman)
Organization: Destructive Testing Systems

In article <18949@mindlink.bc.ca> Bruce_Dunn@mindlink.bc.ca (Bruce Dunn) writes:
>Regarding Geosynchronous satellites launched from a DC-1
>
>        An interesting idea.  Modern comsats have several kilowatts of power,
>enough to run an ion or arcjet engine.  An electric engine running off a few
>kilowatts has a mass of only a few kg, so could easily be carried on the
>vehicle.  The same ion engine could be used for station keeping - all that
>would be required is a larger propellant supply to allow for return to LEO.
>A major problem would probably be radiation damage due to having to spend
>some months in the Van Allen belts as the satellite spirals down to LEO.
>This damages solar cells, but if the array is replacable, this might not be
>too bad.  Other electronics might have to be replaced because of radiation
>damage, but during servicing it might be desirable to replace them anyway for
>updating and extension of service life.

After you discard the solar cells and electronics, what do you have left
but some aluminum framing and a bit of plumbing? It hardly seems worth the 
bother when you consider that you've lost the use of the system for several
months. Transponder time is $400 an hour. For a 24 transponder bird, a
downtime of 3 months equals $20.7 million in lost revenue. You still have
to produce most of the expensive satellite system replacement parts, do an 
LEO launch, EVA servicing requiring major systems overhaul, and reinsertion 
into Clarke orbit. Can you do all that for $20.7 million less than just 
launching a whole new bird with a newly fabricated aluminum frame?

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: roberts@cmr.ncsl.nist.gov (John Roberts)
Newsgroups: sci.space
Subject: Re: SSTO vs 2 stage
Date: 30 Dec 92 05:58:38 GMT
Article-I.D.: cs.C025yp.A1.1
Distribution: sci
Organization: National Institute of Standards and Technology formerly National Bureau of Standards
X-Added: Forwarded by Space Digest
Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU


-From: ewright@convex.com (Edward V. Wright)
-Subject: Re: SSTO vs. 2 Stage
-Date: 29 Dec 92 19:46:24 GMT
-Organization: Engineering, CONVEX Computer Corp., Richardson, Tx., USA

-In <18892@mindlink.bc.ca> Bruce_Dunn@mindlink.bc.ca (Bruce Dunn) writes:
->        We have been launching staged rockets for nearly half a century.  I
->think the problems of staging, if not trivial, are solvable.  Certainly,
->historical evidence indicates that staging is less of a technical challenge
->than SSTO operation.

-You simply do not understand the difference between a converted
-artillery rocket, which we have been launching for nearly half
-a century, and a single-stage-to-orbit *spaceship*.

-Saying that launch vehicles should be multistaged like ICBMs
-makes as much sense as saying that airplanes should be shaped 
-like cannonballs. 

There's a very good argument for multistage rockets - it makes the mass
ratio much simpler to manage (see some of the books by Willy Ley).
Unfortunately, it also adds to the complexity and reliability problems of
the launcher, which is why we'd like to go to SSTO if we can. Thanks to
advances in technology, it may now be practical, and DC will be a great
breakthrough if it works. But that doesn't mean designers were foolish to
use multistage systems in the past - and some applications, such as direct
flight to the moon without refueling, will probably remain unattainable by
SSTO for a long time.

What Bruce is proposing is in part a way to save the situation if SSTO DC
turns out to be *not quite* practical, or if at some point we want to use
DC hardware to put large payloads into orbit without building a large DC.
His argument *supports* further development of DC.

John Roberts
roberts@cmr.ncsl.nist.gov
From: pgf@srl03.cacs.usl.edu ("Phil G. Fraering")
Newsgroups: sci.space
Subject: Re: Aluminum as rocket fuel
Date: 4 Jan 93 03:21:12 GMT
Distribution: sci
Organization: [via International Space University]
X-Added: Forwarded by Space Digest
Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU

\A note of caution:  you're assuming that nitrogen is an inert gas.  This
/isn't necessarily true when hot metals are involved.  I'm not sure about
\aluminum, but I know titanium will burn fiercely in nitrogen (in fact,
/the ash from titanium burning in air is about 80% titanium nitride).
\Without an ignition source, the combination might be stable enough.
/-- 
\"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
/       -Gene Cernan, the Moon, Dec 1972 |  henry@zoo.toronto.edu  utzoo!henry

Titanium nitride... is that Ti N
                              x y
or something along the lines of     Ti N O   ?
                                      x y z 

In short, is this something that will happen without oxygen whatsoever?
-- 
Phil Fraering
"...drag them, kicking and screaming, into the Century of the Fruitbat."
<<- Terry Pratchett, _Reaper Man_
PGP key available if and when I ever get around to compiling PGP...
Newsgroups: sci.space
From: aws@iti.org (Allen W. Sherzer)
Subject: Let's be more specific (was: Stupid Shut Cost arguements)
Organization: Evil Geniuses for a Better Tomorrow
Date: Mon, 28 Dec 1992 20:29:20 GMT

In article <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.

OK Gary you win. I'll accept that there is nothing wrong with Governement
engaging in activities which would get you or I put in jail. It's OK for
NASA to spend $34 billion and then pretend they didn't.

Under these rules, let's look at the costs. The follwoing cost are
from a spreadsheet I put together to evaluate these costs. We get:


                                Shuttle       SSTO
1. Launches per year [1]:         10           10
2. Amortization years [2]:        30           10
3. Development costs [3]:          0         $3,000M
4. Production costs [4]:        $1,500M      $  333M
5. Amortization costs:          $   66M      $   58M
6. Launch costs [6]:            $  550M      $   20M
7. Total launch cost (5 + 6):   $  616M      $   78M
8. Cost per pound to LEO:       $10,272      $  1304

So even ignoring $34 billion in Shuttle costs AND doubling SSTO
costs, SSTO comes out ahead. Even if you doubled Shuttle flight
rates (which not even NASA pretends any more) and quadrupled
all SSTO costs, SSTO still wins.

[1] I used the number of Shuttle launches scheduled for this year and next.
    Doubling this number will not change the end result. For SSTO, I assume
    it takes 80% the domestic MLV market and that the market doesn't grow.
    I think both of these assumptions are unrealistic but it makes SSTO
    look worse.

[2] Amortization happens over 30 years for Shuttle vs 10 years for SSTO.
    SSTO must recoup costs faster since competitors can be expected. Allowing
    SSTO more time will greatly reduce its costs.

[3] Shuttle gets a free ride here. To keep Gary happy we won't worry about
    the $34 billion Shuttle development costs. To also keep Gary happy, we
    WILL amortize SSTO development costs and double those costs just in
    case.

[4] Again, we use Gary's number for the cost of an orbiter. I have doubled
    the cost of an SSTO to add margin for error.

[6] SSTO launch costs are again, double the estimated costs to add a margin.

    Allen
-- 
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  aws@iti.org     |  nothing undone"                                       |
+----------------------117 DAYS TO FIRST FLIGHT OF DCX----------------------+
From: gary@ke4zv.uucp (Gary Coffman)
Newsgroups: sci.space
Subject: Re: Stupid Shut Cost arguements (was Re: Terminal Velocity of DCX?
Date: 31 Dec 92 00:48:31 GMT
Reply-To: gary@ke4zv.UUCP (Gary Coffman)
Organization: Destructive Testing Systems

In article <1992Dec27.205005.22184@iti.org> aws@iti.org (Allen W. Sherzer) writes:
>In article <1992Dec25.014627.4982@ke4zv.uucp> gary@ke4zv.UUCP (Gary Coffman) writes:
>
>>In military procurement, the development costs are charged against
>>the prototypes, X, Y, etc, and the operational vehicles of the procurement 
>>are charged at "flyaway" cost. 
>
>Which I suspect is done largely to hide the true cost. I point out that if
>the contractors in question ran their accounts this way they would all be
>in jail and out of buisness.
>
>>Following this model, Enterprise ate the 
>>development costs, and it's retired. Current Orbiters are only liable for 
>>their $1.5 billion flyaway cost and their operational costs. 
>
>But why should we follow that model? Hiding costs like you advocate only
>encourages waste and inefficiency. How can we possibly make access to space
>cheap if we make it impossible to identify those costs and reduce them?

These costs aren't hidden. They are published and charged to a different
mission, that of R&D. NASA is a R&D operation by charter. Whether the
fruits of that R&D ever flies is a totally separate matter.

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
Newsgroups: sci.space
From: pgf@srl03.cacs.usl.edu ("Phil G. Fraering")
Subject: Acceleration, cats...
X-Added: Forwarded by Space Digest
Organization: [via International Space University]
Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU
Distribution: sci
Date: Wed, 23 Dec 1992 05:09:14 GMT


My last post for a while... btw, thanks to whoever I'm stealing
the neat indenting from ;-)

In article <BznC82.74x.1@cs.cmu.edu> roberts@cmr.ncsl.nist.gov (John Roberts) writes:
] That applies to things that are somewhat resiliant (like humans with their
] limbs not locked), because if deformation continues throughout the period
] of acceleration, then the entire body is not really subjected to the full
] acceleration. (For another example, putting rubber feet or a springy internal
] suspension in a piece of equipment can greatly reduce the maximum shock if
] you drop it.)

Anyone here seen that special they did on TV a while back, about
how some cats have fallen from ten or twenty stories and sometimes
survived (don't try this at home! don't try it with a cat! and especially,
it doesn't work well with humans!)?

What I want to know is, how the ability to fall from 100-150 feet
up was _selected for_ by evolution. It implies that they went through
a period of development where cats that could do that were outcompeting
cats that weren't, to the extent that a large number of cats today can
do it.

Especially since this isn't something that can be done gradually:
the adaptations don't help in falls of 30-60 feet, or much higher than
somewhere around 100 feet (I think)...


Phil

Newsgroups: sci.space
From: 0004244402@mcimail.com (Karl Dishaw)
Subject: Aluminum as Rocket Fuel?
X-Added: Forwarded by Space Digest
Organization: [via International Space University]
Original-Sender: isu@VACATION.VENARI.CS.CMU.EDU
Distribution: sci
Date: Wed, 30 Dec 1992 02:10:48 GMT

I dug into my notes from Aero/Astro project lab, we tried to make a 
fuel feeder for an aluminum/oxygen rocket:

Isp = 118 sec (after accounting for loss due to solid particles)
Must run oxidizer-rich since Al2O3 is a solid.
Main hazard--oxygen getting into Al storage tank.

I'd love to see some info on the Wickman project.  The Isp is too low to 
be really useful, but it would be great for circularizing orbits on mass 
driver-launched payloads, or maybe cheap transport on the lunar 
surface.


Karl
sold my soul to Uncle Sam . . . now marked down for resale.

Newsgroups: sci.space,alt.folklore.urban
From: billn@hpcvaac.cv.hp.com (bill nelson)
Subject: Re: asteroids beyond Jupiter
Organization: Hewlett-Packard Company, Corvallis, Oregon USA
Date: Thu, 24 Dec 1992 19:33:42 GMT

jfurr@polaris.async.vt.edu (J. Furr) writes:
: 
: I post this whole mess to sci.space and say "help" because it seems that
: one side in a.f.u. is arguing as follows: _all_ asteroids occur between
: the orbits of Mars and Jupiter.  Therefore Neptune, Pluto, etc. could not
: possibly have captured asteroids because asteroids don't go out that far.

Not quite. My definition of asteriod is: any body that orginated in the
"asteriod belt" (between Mars and Jupiter). I have made no claim as to  
where they can orbit. Jupiter is large enough to cause significant perturbation
to their orbits.

However, it is a long way from Jupiter to Neptune. I am waiting for someone
to post a reference that states that there are asteriods (by my definition)
that orbit that far out.

Bill
From: David.Anderman@ofa123.fidonet.org
Newsgroups: sci.space
Subject: Re: LEI financing
X-Sender: newtout 0.02 Nov 17 1992
Date: 22 Dec 92  23:33:22

Henry, based on past performance, I would agree that the chances of passage of 
the Lunar Resources Data Purchase Act were low. However, several things have
occurred this year that make it a better chance than in the past:
 
Daniel Goldin. Under his administration, NASA is saying and doing things that 
would have been hard to imagine years ago. Their Procurement office is talking 
about not only purchasing lunar, but also Martian, data as well. It is
possible that the LRDPA (what an acronym) may become obsolete next year, as
NASA may decide, through the President, to request funding for purchase of
lunar data.
 
 
Congress. This organization did pass the Launch Services Purchase Act, and did 
extend it last year in certain areas. There is interest in the right places
for this type of legislative initiative.
 
I wouldn't say that passage of the Back to the Moon bill is a snap, but I will 
say that the enemy of the Bill is not NASA, the Congress, or the lunar science 
community - the enemy is apathy.

--- Maximus 2.01wb
Newsgroups: sci.space
From: gary@ke4zv.uucp (Gary Coffman)
Subject: Re: Terminal Velocity of DCX? (was Re: Shuttle ...)
Reply-To: gary@ke4zv.UUCP (Gary Coffman)
Organization: Destructive Testing Systems
Date: Thu, 31 Dec 1992 00:19:42 GMT

In article <1hfqr6INN387@mirror.digex.com> prb@access.digex.com (Pat) writes:
>Consider that the russians/CIS/USSR  built a major space program with
>the GNP the size of France.   And by the Way,  unlike the germans, or chinese
>i dont believe the russians have ever been charged with using slave
>labor.  Now the russians had a strange command economy,  but things still
>cost, but there were major problems in distribution.  the russian/SU
>economy was sorta like massachusetts meets new york via sweden.
>
>high taxes,  severe rent control and social provision of major services.
>
>SUre,  they didnt pay their scientists what we paid them here,  but they
>provided them with housing, medicine, etc.   Also,  the motivation of most
>russian space workers was so great,  that they didn't mind the bad conditions.
>
>the problems within the russian system, were of productivity,  design cycle,
>and provision of consumer goods.
>
>The chinese use slave labor,  and then sell it over here.  the russians
>paid their workers poorly,  and the workers pretended to work.
>
>the gulags were not used as factories to my knowledge.

I agree with all of this. My point was that all those social services,
which in our system are paid out of worker salaries, were paid out of
a different account that wasn't charged against their space program. 
So using their numbers is an invalid comparison with numbers from a
differently organized economy because many of their costs are "hidden"
in other government accounts. That looks like it's changing, and we
may soon discover that Russian costs *aren't* really much lower than 
ours for similar launchers.

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:18497 talk.politics.space:1652
From: lafave@ial4.jsc.nasa.gov (Dr. Norman J. LaFave)
Newsgroups: sci.space,talk.politics.space
Subject: Re: Government-run programs  Was: Re: Justification for the Space Program
Date: 31 Dec 92 15:56:18 GMT
Organization: Lockheed Engineering & Sciences Company
X-Xxdate: Thu, 31 Dec 92 09:52:36 GMT
X-Useragent: Nuntius v1.1.1d12

In article <1992Dec31.015903.15161@cs.rochester.edu> Paul Dietz,
dietz@cs.rochester.edu writes:
>Well, Doc, I can't, because I do not recall where or just when this
>poll was conducted (it was some years ago).

Here's a clue Paul, the results of polls change with time and not all
polls are accurate.

>However, if you wish to
>call me a liar about it, I shall try to cope.

I'm not calling you a liar Paul. However I am a scientist, and as a
scientist,
I like to make my own judgements.

Norman

Dr. Norman J. LaFave
Senior Engineer
Lockheed Engineering and Sciences Company




When the going gets weird, the weird turn pro
                               Hunter Thompson
From: nsmca@acad3.alaska.edu
Newsgroups: sci.space
Subject: Alaska, Poker Flats
Date: 23 Dec 92 23:34:12 GMT
Article-I.D.: acad3.1992Dec23.153412.1
Organization: University of Alaska Fairbanks

Does anyone know anything about the University of Alaska Fairbanks Poker Flats
space program..
Michael Adams alias Ghost Wheel/Morgoth NSMCA@acad3.alaska.edu
Newsgroups: sci.space