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Date: Thu, 31 Dec 92 05:00:10
From: Space Digest maintainer <digests@isu.isunet.edu>
Reply-To: Space-request@isu.isunet.edu
Subject: Space Digest V15 #613
To: Space Digest Readers
Precedence: bulk
Space Digest Thu, 31 Dec 92 Volume 15 : Issue 613
Today's Topics:
Acceleration
Aluminum as Rocket Fuel?
Astro FTP list - December issue
averting doom (2 msgs)
DC vs Shuttle capabilities
Justification for the Space Program
Moral Justification (2 msgs)
Saturn lift capabilities
Space List Flame Wars
Stupid Shut Cost arguements (was Re: Terminal Velocity (2 msgs)
Welcome to the Space Digest!! Please send your messages to
"space@isu.isunet.edu", and (un)subscription requests of the form
"Subscribe Space <your name>" to one of these addresses: listserv@uga
(BITNET), rice::boyle (SPAN/NSInet), utadnx::utspan::rice::boyle
(THENET), or space-REQUEST@isu.isunet.edu (Internet).
----------------------------------------------------------------------
Date: Wed, 30 Dec 92 08:47:52 EST
From: John Roberts <roberts@cmr.ncsl.nist.gov>
Subject: Acceleration
-From: gene@wucs1.wustl.edu (_Floor_)
-Subject: Re: Acceleration
-Date: 29 Dec 92 16:22:35 GMT
-In article <C00wHv.HK7.1@cs.cmu.edu> roberts@cmr.ncsl.nist.gov (John Roberts) writes:
-] -Small force? I think they said the probe would feel an acceleration of 350 g's.
-] ------------
-] -It's receiving a force 350 times that of Earth's gravity at the surface of
-] -the Earth. That's quite a bit of force if you ask most people.
-] -----
-]
-] - Gene Van Buren, Kzoo Crew(Floor), Washington U. in St. Lou - #1 in Volleyball
-]
-] Acceleration and force are not the same thing. In this case, acceleration
-] is force *per unit mass*. If you can keep the mass down on any given
-] component, then the force isn't too great, even under high acceleration.
-F=ma, right? So if the mass is the same, then an acceleration 350 times
-that experienced on earth is due to a force 350 times that on earth, right?
That's right. So if you can make "m" small enough, then you can keep "F"
manageable even if "a" is large. Of course, strength also decreases with
decreasing mass, but not linearly - I believe strength per unit mass generally
increases with decreasing size [2]. So if you scaled an ant or daddy longlegs
spider up to a mass of ten tons, the poor critter wouldn't be able to move
(numerous science fiction films notwithstanding). If you dropped Big Ben
onto a concrete surface, it probably wouldn't fare as well as a wristwatch
subjected to similar acceleration. :-)
[2] There are at least two relevant factors - the square-cube law, and
surface effects.
John Roberts
roberts@cmr.ncsl.nist.gov
------------------------------
Date: 30 Dec 92 15:41:48 GMT
From: John Thompson Reynolds <juan@nuala.hal.COM>
Subject: Aluminum as Rocket Fuel?
Newsgroups: sci.space
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
------------------------------
Date: Wed, 30 Dec 1992 09:56:59 GMT
From: M{kel{ Veikko <pvtmakela@hylkn1.Helsinki.FI>
Subject: Astro FTP list - December issue
Newsgroups: sci.astro,sci.space
#
# A S T R O - F T P L I S T
# Updated 28.12.1992
#
# This is a short description of anonymous-ftp file servers containing
# astronomy and space research related material. I have included only those
# servers where there are special subdirectories for astro stuff or much
# material included into a general directories. This list is not a complete
# data set of possible places, so I would be very happy of all kind of notices
# and information depending on this listing.
#
# The newest version of this file is available via anonymous-ftp as:
#
# nic.funet.fi:/pub/astro/general/astroftp.txt
#
# There are also many mirror (copy) archives for simtel-20.army.mil (PC) and
# sumex-aim.stanford.edu (Mac) which are not included into this list. Only some
# of mirroring sites are listed.
#
#
# Veikko Makela
# Veikko.Makela@Helsinki.FI
# *Computing Centre of Univ. Helsinki*
# *Ursa Astronomical Association*
# Server, IP # Contents
# Directories
akiu.gw.tohoku.ac.jp images
130.34.8.9
/pub/gif/astro
/pub/gif/nasa
ames.arc.nasa.gov spacecraf data and news,images,NASA data,
128.102.18.3 Spacelink texts,VICAR software,FAQ,files
/pub/SPACE from mandarin.mit.edu
atari.archive.umich.edu Atari
141.211.164.8
/atari/applications/astronomy
archive.afit.af.mil Satellite software,documents,elements
129.92.1.66
/pub/space
baboon.cv.nrao.edu AIPS document and patches,radioastronomy
192.33.115.103 image processing,FITS test images
/pub/aips
c.scs.uiuc.edu ROSAT,Starchart(PC)
128.174.90.3
/pub
capella.eetech.mcgill.ca garbo.uwasa.fi c.,archive.umich.edu c.,
132.206.1.17 other mirrors
/wuarchive/mirrors3/
ccu1.aukuni.ac.nz PC
130.216.1.5
/msdos/astronomy (*) overseas connections refused
chara.gsu.edu Electronical Journal of ASA
131.96.5.10
/asa
daisy.learning.cs.cmu.edu Space technology texts
128.2.218.26
/public/space-tech
explorer.arc.nasa.gov Magellan, Viking and Voyager CDROMs
128.102.32.18
/cdrom
epona.physics.ucg.ie Some software,predictions,images
140.203.1.3
/pub/astro
/pub/space/pics
fits.cv.nrao.edu FITS documents, OS support, sample data,
192.33.115.8 test files, sci.astro.fits archive
/FITS
ftp.cco.caltech.edu Astronomy magazine index 1991
131.215.48.200
/pub/misc
ftp.cs.tu-berlin.de PC,Amiga,general
130.149.17.7
/pub/astro
ftp.funet.fi PC,Mac,CP/M,Atari,Amiga,databases,Unix,
128.214.6.100 HP48,OS/2,texts,News,solar reports,images,
/pub/astro Satellite elements,FAQ
ftp.uni-kl.de iauc,Vista image reduction,asteroids
131.246.9.95
/pub/astro
garbo.uwasa.fi PC
128.214.87.1
/pc/astronomy
gipsy.vmars.tuwien.ac.at images
128.130.39.16
/pub/spacegifs
hanauma.stanford.edu Unix, satellite program
36.51.0.16
/pub/astro
ics.uci.edu images
128.195.1.1
/astro
idlastro.gsfc.nasa.gov IDL routines
128.183.57.82
/
iear.arts.rpi.edu images
128.113.6.10
/pub/graphics/astro
iraf.noao.edu IRAF Software
140.252.1.1
/iraf
iris1.ucis.dal.ca images
129.173.18.107
/pub/gif
julius.cs.qub.ac.uk Space Digest
143.117.5.6
/pub/SpaceDigestArchive
kauri.vuw.ac.nz Astrophysical software
130.195.11.3
/pub/astrophys
kilroy.jpl.nasa.gov Satellite elements,spacecraft info
128.149.1.165
/pub/space
lowell.edu Vista image reduction
192.103.11.2
/pub/vista
mandarin.mit.edu Comets,asteroids,SAC,databases,Ephem,PC
18.82.0.21 (*) unavailable since December 1992,
/astro no information about the future
minnehaha.rhrk.uni-kl.de Starchart,iauc index
131.246.9.116
/pub/astro
mcshh.hanse.de PC
192.76.134.1
/pub/msdos/astronom
ns3.hq.eso.org Test images
134.171.11.4
/pub/testimages
nssdca.gsfc.nasa.gov HST,IUE,Astro-1,NSSDCA info,Spacewarn,
128.183.36.23 FITS standard
/
osgate0.mei.co.jp images
132.182.49.2
/free/others/SPACE
pioneer.unm.edu spacecraf data,catalogs,image processing
129.24.9.217
/
plaza.aarnet.edu.au images,docs,garbo.uwasa.fi c.
139.130.4.6
/graphics/graphics/astro
/micros/pc/garbo/astronomy
pomona.claremont.edu Yale Bright Star Catalog
134.173.4.160
/YALE_BSC
puffin.doc.ic.ac.uk archive.umich.edu c.,other mirrors
146.169.3.7
/mac/umich/graphics/astronomy
ra.nrl.navy.mil Mac
128.60.0.21
/MacSciTech/astro
rascal.ics.utexas.edu Mac
128.83.138.20
/mac
rigel.acs.oakland.edu PC
141.210.10.117
/pub/msdos/astronomy
rusmv1.rus.uni-stuttgart.de Atari
129.69.1.12
/soft/atari/applications/astronomy
scavengerhunt.rs.itd.umich.edu Mac
141.211.164.153
/mac/graphics/astronomy
simtel20.army.mil PC,CP/M
192.88.110.20
/msdos/educ
/cpm
sol.deakin.oz.au garbo.uwasa.fi c.
128.184.1.1
/pub/PC/chyde/astronomy
sola.fcit.monash.edu.au HP48
130.194.224.224
/HP48/seq/astronomy
/HP48/seq/misc
solar.stanford.edu Solar reports
36.10.0.4
/pub
solbourne.solbourne.com some PC programs
141.138.2.2
/pub/rp/as-is/astro
stardent.arc.nasa.gov Martian map
128.102.21.44
/pub
stsci.edu HSTMap(Mac),HST info
130.167.1.2
/Software
sumex.stanford.edu Mac
36.44.0.6
/info-mac/app
sun0.urz.uni-heidelberg.de PC,misc
129.206.100.126
/pub/msdos/astronomy
tetra.gsfc.nasa.gov FITSIO subroutines
128.183.8.77
/pub/fitsio
unbmvs1.csd.unb.ca Space geodesy,solar activity info
131.202.1.2
pub.canspace
vab02.larc.nasa.gov images
128.155.23.47
/gifs/space
vmd.cso.uiuc.edu Weather satellite images
128.174.5.98
/wx
xi.uleth.ca Solar reports,auroral activity forecast
142.66.3.29 maps,solar images,x-ray plot,coronal
/pub/solar emission plots
# Some abbreviations:
#
# c = copy (mirror) of other archive
# -----
# My other e-communication projects:
# * E-mail contact addresses of interest groups in amateur astronomy
# * European astronomy and space-related bulletin boards
# * E-mail catalogue of Finnish amateur astronomers
------------------------------
Date: 30 Dec 92 13:54:55 GMT
From: Andrew - Palfreyman <lordSnooty@cup.portal.com>
Subject: averting doom
Newsgroups: sci.astro,sci.space,sci.physics,sci.environment
I like the simplicity of this idea (moving the Earth instead of
trying to shield it), but what the heck's all this "elastic
collisions" stuff? Surely you're not serious about the "broken
Kepler" business?
Instead, I'd use the "tame asteroid" in a resonant slingshot
configuration between (say) Mars and Earth, in order to bring
Mars "down" and Earth "up" the Sun's gravitational potential
well. Hell, use a string of 'em to speed things up.....
--------------------------------------------------------------------------
| lord snooty @the giant | Would You Like Space Potatoes With That? |
| poisoned electric head | andrew_-_palfreyman@cup.portal.com |
--------------------------------------------------------------------------
------------------------------
Date: 30 Dec 92 14:10:19 GMT
From: Len Evens <len@schur.math.nwu.edu>
Subject: averting doom
Newsgroups: sci.astro,sci.space,sci.physics,sci.environment
In article <JMC.92Dec29211051@SAIL.Stanford.EDU> jmc@cs.Stanford.EDU writes:
>from a U.P. story
[Some very interesting speculation about the possibility of moving the
planet to avoid the consequences over hundreds of millions of years
---the last estimate I saw in a news story was just under a billion---
of the gradual heating of the sun.]
>
>
>By the way, it seems to me that if the above idea is sound, it settles
>the question of the stability of the solar system - in the negative.
If you don't mind a quibble from a mathematician, the mathematical question
of stability refers to whether a dynamical system following Newton's
laws and which is an idealization of the solar system stays bounded
for all time (or some related question of this type). McCarthy's
speculation proposes the use of nuclear explosions to deflect an
asteroid. This takes us out of the realm of dynamics. If we depart
from that realm, it is perfectly obvious that the solar system is
not a stable system. For example, what is likely to happen if the
the sun goes nova?
>Very likely an asteroid could be tamed over a sufficiently long time
>with as small an expenditure of delta-v as might be desired. Once
>tamed it could be used with infinitesimal external force to expel a
>planet from the system. This tells us that the current trajectory of
>the solar system is arbitarily close to one in which a planet is
>expelled. Of course, the probability that a planet actually would be
You would need a whole lot more mathematics than the rough estimates
made in McCarthy's exposition to establish this. I suspect the
clever people studying celestial mechanics have looked into
all the obvious small perturbations of this kind long ago, but
perhaps not. I will ask my local expert.
>expelled by this mechanism in some particular finite time is extremely
>low, because maintaining the required sequence of encounters requires
>an improbable precision in the initial conditions. I suppose a lower
>bound on the probability could be computed and from it an expected
>upper bound on the gravitational lifetime of the solar system could be
>obtained.
>
>Criticism and comments are welcome. For a certain reason, I even
>welcome comments, however uninformed, to the effect that the whole
>idea is preposterous. I prefer such comments to be postings rather
>than email.
>
It seems to me that this type of speculation takes us a bit beyond
science but perhaps not inexcusably. Those interested in the earth's
history, particularly future history, certainly can't propose experiments
or observations which will directly confirm such predictions over
what is often called deep time. McCarthy's point is basically that
the existence of intelligence may have profound effects. This point has
been made before. For example, Dyson proposed that advanced civilizations
might move all the mass in a star system into a sphere surrounding
the star thus capturing all its radiation and living on the inside
of the sphere. As Steven Jay Gould has pointed out, this may be
a limited perspective. We tend to think of evolution as an upward
process leading to us where it more or less stops. In fact, it is quite
possible that intelligence is an evolutionary side show which will shortly
disappear. There may be no ancestors around to engage in planetary
engineering when the time comes.
>What would be most welcome is a collaborator on a paper that could
>be published in _Nature_.
>--
>John McCarthy, Computer Science Department, Stanford, CA 94305
>*
>He who refuses to do arithmetic is doomed to talk nonsense.
>
I think the analysis needs a lot more mathematics than arithmetic.
Unforutnately, I don't know enough of the right kind to help, but
I will pass this idea on to my colleagues who do.
Leonard Evens len@math.nwu.edu 708-491-5537
Dept. of Mathematics, Northwestern Univ., Evanston, IL 60208
------------------------------
Date: 30 Dec 92 04:15:57 GMT
From: Rich Kolker <rkolker@nuchat.sccsi.com>
Subject: DC vs Shuttle capabilities
Newsgroups: sci.space
In article <ewright.725671037@convex.convex.com> ewright@convex.com (Edward V. Wright) writes:
>In <1992Dec29.202546.12526@aio.jsc.nasa.gov> hack@arabia.uucp (Edmund Hack) writes:
>
>>5. The weight margins on the vehicle are very tight, a historical source
>>of problems in spacecraft and aircraft design.
>
On the contrary, the weight margins are quite generous. They include not
only a "dry weight" margin, but a margin for lower isp than expected and
a couple of things I don't remember (i'll be getting the report I read soon).
The 10,000 lb to polar orbit, or 24,800 to LEO are based on worst
case of all these margins. If they turn out better (i.e. if expected
values are reached) the payload increases.
-------------------------------------------------------------------
rich kolker rkolker@nuchat.sccsi.com
< Do Not Write In This Space>
--------------------------------------------------------------------
------------------------------
Date: 30 Dec 92 16:01:58 GMT
From: Josh Diamond <jmd@bear.com>
Subject: Justification for the Space Program
Newsgroups: talk.politics.space,sci.space,alt.rush-limbaugh
In article <1992Dec29.232413.25117@cs.rochester.edu> dietz@cs.rochester.edu (Paul Dietz) writes:
(2) Estimates of the metal content of the Gorda Ridge polymetallic
sulfides -- which are in the US economic exclusion zone -- range
up to 10^9 tons (although noone knows for sure, as they are not
economical at this time.) These deposits are somewhat different
from nodules, containing significant silver and gold.
Also, some of the Pacific nodules are within 200 miles of various
island nations, so only those nations, not the UN/etc., must be
dealt with the exploit those resources.
Did it ever occur to anyone out there to consider the environmental
impact of large scale disruption of the sea floor? I could result in
severe problems with algal blooms and plankton die-offs, with effects
all the way up the food chain...
Spidey!!!
--
You don't hunt ducks with a turnip!
/\ \ / /\ Josh Diamond jmd@bear.com
//\\ .. //\\ AKA Spidey!!! ...!ctr.columbia.edu!ursa!jmd
//\(( ))/\\
/ < `' > \ Do whatever it takes.
------------------------------
Date: Wed, 30 Dec 1992 14:32:34 GMT
From: Hartmut Frommert <phfrom@nyx.uni-konstanz.de>
Subject: Moral Justification
Newsgroups: sci.space
18084TM@msu.edu (Tom) writes:
[stuff deleted]
>Sorry. Valuable, perhaps, but not moral.
>1) If it has such a good return, why do we need the gov. to pay for it?
Who needs a gov ? :-))
>2) How do you convince that factory worker that lost his job to a robot
> that his money should be spent to help put him on the street?
If I'm not totally misinformed there are at least as many jobs created by
modern technology as go lost to robots. At least in Europe there was a debate
on the dangers of the computer in the late 70s: many people feared that they
could destroy their jobs, and that the government could introduce a "Great
Brother" system supervising and controling them. Now everybody has a PC which
often changed the job but in no way destroyed it, and there are extra jobs
that are now possible and could not be done w/o comp. The problem for the
worker will probably be (on longer terms) that he must qualify again for a
new job, and some people will fail, since hightech usually requires more
skilled workers.
Hartmut Frommert <phfrom@nyx.uni-konstanz.de>
Dept of Physics, Univ of Constance, P.O.Box 55 60, D-W-7750 Konstanz, Germany
-- Eat whale killers, not whales --
------------------------------
Date: Wed, 30 Dec 1992 16:43:30 GMT
From: gawne@stsci.edu
Subject: Moral Justification
Newsgroups: sci.space
> 18084TM@msu.edu (Tom) asks:
>
>>2) How do you convince that factory worker that lost his job to a robot
>> that his money should be spent to help put him on the street?
I guess there are two issues here. First is the question of "fair"
use of tax revenues and second is the question of automation.
While I agree that governments often spend tax revenues foolishly,
I think that subsidies to industry can be good. If the subsidy is
in some part funded by revenues obtained by taxing those who
become unemployed as a result then it is in the interest of both
the taxing authority (govt) and industry to provide new employment
opportunities. If the source of revenue (the taxpayer) stops paying
taxes then what?
As for the second implicit point, that of a worker being replaced
because of change, it sort of reminds me of the story of the
farrier who went to court to try to get automobiles outlawed in
his town because it threatned his horseshoeing business.
Or as my grandmother used to say, "Time and tide wait for
no-one." You can either change along with the world or
let it leave you behind.
-Bill Gawne, Space Telescope Science Institute
------------------------------
Date: 30 Dec 1992 16:24:49 GMT
From: Pat <prb@access.digex.com>
Subject: Saturn lift capabilities
Newsgroups: sci.space
Henry.
Given the opinion of the science community on ASTP,
why didn't we have the ASTP mission meet at Skylab?
Then a Full-up CSM could have been used to give
skylab a push, the vehicle could have been flown
fora fourth mission, and the soviets could have
docked on the other end.
Was skylabs orbit too low in inclination for them to hit it?
------------------------------
Date: Wed, 30 Dec 92 08:42:00
From: <KitchenRN@ssd0.laafb.af.mil>
Subject: Space List Flame Wars
I subscribed to this list in order to try to inform myself about the latest
news about US and other coutnries' space programs. I thought that this would
be a list of technical discussions, not a religious debate that has turned
into ad hominem attacks and flame wars as virulent as any I've seen in the
religious news groups. Then I see things like this, from Herman Rubin:
>Let those who want to support research decide. But get the governments
>out of the way, including out of levying taxes on money going to research.
>If the government was not involved in the business of vainly trying to
>manage charity, which it does in such a way as to make it financially
>advantageous for at least many of those on welfare to do nothing about
>the problem, and in the business of keeping our children very poorly
>educated, and in general making it expensive to do anything of which
>the government diasapproves, there would be the money for space activities.
and this from Henry Spencer:
>We'll be mining in space long before we exploit any of the sea-bottom
>resources. The socialists rule the oceans and don't want any dirty
>capitalist mining venture making money off the "common property of
>mankind". The US State Department was on the brink of giving them the
>rest of the universe too, but the L5 Society (may it rest in peace)
>managed to block Senate ratification of the infamous Moon Treaty.
Such political ranting belongs in the alt.talk.politics or alt.religion
groups. Could we please take them out of the space list?
In addition, there is much too much signal to noise ratio in the flame wars
and the ad hominem attacks. Could we move them out of the list and into
private emails? There is too much heat and not enough light coming out
of them.
I know that I have now left myself wide open to being attacked from all
sides, but I just thought that, considering the size of the mailings that I'm
getting, there is too much of this stuff to wade through to get to anything
worth reading.
------------------------------
Date: 30 Dec 92 13:43:00 GMT
From: "Allen W. Sherzer" <aws@iti.org>
Subject: Stupid Shut Cost arguements (was Re: Terminal Velocity
Newsgroups: sci.space
In article <JMC.92Dec29222737@SAIL.Stanford.EDU> jmc@cs.Stanford.EDU writes:
>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.
DC-X is being built so that the answer can be evaluated experimentally.
Allen
--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves |
| aws@iti.org | nothing undone" |
+----------------------115 DAYS TO FIRST FLIGHT OF DCX----------------------+
------------------------------
Date: 30 Dec 92 14:53:49 GMT
From: "Allen W. Sherzer" <aws@iti.org>
Subject: Stupid Shut Cost arguements (was Re: Terminal Velocity
Newsgroups: sci.space
In article <72596@cup.portal.com> BrianT@cup.portal.com (Brian Stuart Thorn) writes:
>>Sorry for the misunderstanding. No, I suspect 10 flights a year is possible.
>>I doubt 12 can be done without MAJOR changes.
>>But given the very poor record of Shuttle performance to schedule, I assert
>>the burden of proof is on you to show 12 can be done. I'll accept any two
>>consecutive calendar years with 24 launches.
> One year doesn't go a long way statistically, but 1992 had a pretty
> good record.
For eight flights. That doesn't mean an increase of 25 to 50 percent is
easy.
> Agreed, the proof is in the pudding. Alas, political pressures being
> what they are, NASA is unlikely to get the chance to prove it.
What exactly are these pressures you are talking about? As to wether
these pressures exist or not is not relevant. The bottom line is that
Shuttle can't fly (for whatever reason) much more than it is now.
> Will sixteen launches in two years at least give you some cause
> to believe that Shuttle is not yet working at maximum capacity?
That's why I said ten flights.
> By the way,
> if Endeavour flies on January 13, that will be nine launches in a
> twelve month period.
Means nothing.
>>A DC is simple and reliable enough that 50 flights a year is reasonable
> Essentially the same thing was said in 1972 regarding Shuttle.
True enough. So what are we to do? In these situations I like to look
at the design of the vehicle, not worry about claims made by dis-similar
vehicles in the past. When one builds a complex vehicle which pushes the
technology everywhere, it comes as no suprise that it doesn't work very
well. But when one looks at a simple vehicle which makes maximum use
of exsiting technology it is a lot easier to expect success.
> It wasn't true then, but this is the first time I've ever seen
> you use the phrase "if DC works".
Then you aren't reading my postings very carefully.
> Heretofor it has been "there's no reason it won't work.
I also say that. Both are true statements. To date nobody has proposed
any real show stoppers to SSTO. Not you, not gary not NASA. Your matra
of 'shuttle failed so DC will fail' simply isn't a good technical
arguement.
Now it you do want to see a good arguement against SSTO, see John
Roberts recent posting. There he does a good job of identifying
the risk areas and showing the technical problems.
> As you just said, ten per year is 100% of Shuttle's capacity without
> raising costs. So why is Shuttle flying only eight times per year?
You need to ask NASA for the final answer. It could well be that I am
wrong and 8 is the max flight rate.
> That is the argument used to justify cancellation of all manned
> space activities. Is that what you are suggesting, Allen?
Manned space has a reputation for being horendously expensive. Currently
it is but need not always be expensive. By blindly supporting vehicles
which are so hugely expensive simply because they are manned we:
1. Give ammunition to our enemies who can point to Shuttle and argue that
manned space is too expensive.
2. Stifle efforts to reduce costs.
3. Lure us into a false sense of complacency by thinking that progress
is being made when in fact it isn't.
I am a strong supporter of manned space and the current stagnation we
are seeing distresses me. Seeing other supporters working to maintain
that stagnation is even more distressing.
> Your claims as to DC's performance before the thing ever flies
> doesn't wow the public, either.
I disagree. I was recently interviewed for an upcoming article on
DC in a British newspaper. I have received requests from other
papers as well. I know of other media interested in covering the
DCX tests. Hundered of people have volunteered to meet with their
representatives on this. These are not the actions of disinterested
people.
> I pointed out four recent high
> tech space programs that failed to meet their goals.
so what? You cannot conclude from that anything about any future
program. Pick your favorite future effort. Do you think it will
fail just because some past efforts failed?
> unless we go buy Soyuz from Russia, what options do we have?
I think that's a hell of a good option. It saves money and promotes
commercial space. What more do we want?
>>There isn't a payload in existance today which can't go up on either.
> Some people say GRO and Hubble are examples, I'm not sure.
The USAF has a Titan IV faring which is fully Shuttle compatible.
> into LEO. Then you can dig up Delta facts and figures and justify
> its construction.
Sure.
>>More of the same; I'll bet you $50 that it starts flying regularly. Well?
> I'm sure it will too, my point is that it wasn't easy getting there.
No disagreement. It may also be hard for DC. Let's find out.
Allen
--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves |
| aws@iti.org | nothing undone" |
+----------------------115 DAYS TO FIRST FLIGHT OF DCX----------------------+
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End of Space Digest Volume 15 : Issue 613
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