Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v11_0/v11_082.txt

Internet Message Format | 1991-07-08 | 20KB

Return-path: <[e-mail]>
X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson
Received: from beak.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr11/tm2b/space/[e-mail] (->+dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl) (->ota+space.digests)
          ID </afs/andrew.cmu.edu/usr1/ota/Mailbox/sZuAlTu00VcJICoU53>;
          Mon, 26 Feb 90 01:27:44 -0500 (EST)
Message-ID: <[e-mail]>
Reply-To: [e-mail]
From: [e-mail]
To: [e-mail]
Date: Mon, 26 Feb 90 01:27:20 -0500 (EST)
Subject: SPACE Digest V11 #82

SPACE Digest                                      Volume 11 : Issue 82

Today's Topics:
              NASA Prediction Bulletins
      Re: Fun Space Fact #1: Launcher Development Costs
         Wanted: images of craters or other surfaces
         Wanted: images of craters or other surfaces
            Re: NASA Prediction Bulletins
        Re: New private home satellite network
       Re: Fun Space Fact #1: Launcher Development Costs (long)
       Re: Fun Space Fact #1: Launcher Development Costs (long)
----------------------------------------------------------------------

Date: 25 Feb 90 05:40:21 GMT
From: pasteur!helios.ee.lbl.gov!ncis.tis.llnl.gov!blackbird![e-mail]  (TS Kelso)
Subject: NASA Prediction Bulletins


The most current orbital elements from the NASA Prediction Bulletins are
carried on the Celestial RCP/M, [phone], and are updated several times
weekly.  Documentation and tracking software are also available on this
system.  As a service to the satellite user community, the most current of
these elements are uploaded weekly to sci.space.  This week's elements are
provided below.  The Celestial RCP/M may be accessed 24 hours/day at 300,
1200, or 2400 baud using 8 data bits, 1 stop bit, no parity.

- Current NASA Prediction Bulletins #651 -
Alouette 1
1 00424U 62B-A  1 90 49.50739522  .00000176  00000-0  20256-3 0  2608
2 00424  80.4611  43.0727 0022273 216.2518 143.7103 13.67294553366476
ATS 1
1 02608U 66110  A 90 51.86237162 -.00000204  00000-0  99999-4 0  1099
2 02608  13.4436  14.6802 0005843 255.4378 104.5483  1.00389060  1388
ATS 3
1 03029U 67111  A 90 50.93793706 -.00000075  00000-0  99999-4 0  2937
2 03029  13.0578  22.1730 0032036 199.6822 160.3072  1.00272408 81626
Cosmos 398
1 04966U 71 16  A 90 50.98395242  .00025172  16803-4  15495-3 0  5785
2 04966  51.5381 168.5227 2366861 289.7650  46.4367 10.85690858578853
Starlette
1 07646U 75010  A 90 50.72287824 -.00000054  00000-0  53998-5 0   125
2 07646  49.8251 261.9714 0206474 163.2409 197.5440 13.82130281759530
LAGEOS
1 08820U 76039  A 90 49.41237959  .00000003  00000-0  00000 0 0    55
2 08820 109.8635 314.4459 0044679 263.5566  96.0061  6.38664448 66356
GOES 2
1 10061U 77048  A 90 46.00000000 -.00000258  00000-0  99999-4 0  3633
2 10061   7.7624  65.4409 0000805 193.4731 191.6728  1.00264670  7811
GPS-0001
1 10684U 78020  A 90 49.26722362  .00000008  00000-0  99999-4 0  3270
2 10684  63.6543  93.2278 0116277 199.2899 160.3272  2.00557131 73465
GPS-0002
1 10893U 78 47  A 90 50.23356658 -.00000026  00000-0  00000 0 0   987
2 10893  64.4379 334.0603 0162021  25.7076 335.1238  2.00549132 86302
GOES 3
1 10953U 78062  A 90 47.14404981  .00000086  00000-0  99999-4 0  8163
2 10953   6.6425  67.9654 0006417 253.8525 106.2050  1.00280854  3384
SeaSat 1
1 10967U 78064  A 90 49.02606463  .00000472  00000-0  20749-3 0  2358
2 10967 108.0197  74.3019 0002501 239.1761 120.9161 14.35417458609357
GPS-0003
1 11054U 78093  A 90 45.04811199 -.00000025  00000-0  00000 0 0  1640
2 11054  63.9829 330.5682 0056165 117.6506 242.9586  2.00565837 83212
Nimbus 7
1 11080U 78098  A 90 46.23034806  .00000060  00000-0  70472-4 0  6321
2 11080  99.2026 313.8734 0009779  51.5494 308.6557 13.83395456571171
GPS-0004
1 11141U 78112  A 90 50.62866880  .00000008  00000-0  00000 0 0  2692
2 11141  63.6819  93.0923 0059436 316.8517  42.7533  2.00563227 82020
NOAA 6
1 11416U 79 57  A 90 49.10834964  .00000623  00000-0  27425-3 0  9712
2 11416  98.5208  44.3455 0012777 108.8469 251.4077 14.26480011552951
GPS-0005
1 11690U 80 11  A 90 50.26876934  .00000010  00000-0  00000 0 0  9064
2 11690  64.1330  95.0999 0144366 198.4554 160.9414  2.00555588 87870
GPS-0006
1 11783U 80 32  A 90 49.08682440 -.00000025  00000-0  00000 0 0   423
2 11783  63.7583 330.0205 0146556  60.4186 301.0606  2.00573439 71938
GOES 4
1 11964U 80 74  A 90 46.73288440 -.00000050  00000-0  00000 0 0  1341
2 11964   6.1256  70.6580 0030373 107.7644 252.7270  0.99231736  4441
GOES 5
1 12472U 81049  A 90 48.99247081 -.00000242  00000-0  99999-4 0  8244
2 12472   3.1761  77.2953 0001376 222.5361 137.7015  1.002

------------------------------

Date: 24 Feb 90 23:35:03 GMT
From: attcan!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Fun Space Fact #1: Launcher Development Costs

In article <[e-mail]> [e-mail] (Nick Watkins) writes:
>>[Boisjoly]
>>But before you weep too hard for him, read the Rogers Commission report,
>>noticing what he did and didn't (mostly didn't) do at the time...
>
>I *did* read it (Vol 1 anyway, to which I assume you refer), obviously I
>need to read it again...

I recommend it.  Note particularly the part where the teleconference,
including Boisjoly, resumes, and after some discussion, the question is
asked [roughly] "does anybody have any problems with launching tomorrow?",
and there is silence on the line.

>... However, a system in
>which people are penalised for honesty (even if only after the fact)
>does not augur well for the future of NASA or the contractors, at least
>in terms of achieving the goals you'd like to see them achieve...

Very true, alas.  Likewise a system that rewards people for their complicity
in the disaster.  What, you thought Morton Thiokol was *penalized* for what
they did?  Ho ho, not so.  They got umpty-million dollars to fix the SRB
problems, and the notion of an alternate source for SRBs was shelved for
years.  Isn't that a *wonderful* example for the next time some engineer
tries to convince his management that they should do the right thing?
--
"The N in NFS stands for Not, |     Henry Spencer at U of Toronto Zoology
or Need, or perhaps Nightmare"| uunet!attcan!utzoo!henry [e-mail]

------------------------------

Date: 25 Feb 90 04:17:34 GMT
From: mcgill-vision!clyde.concordia.ca!sherlock![e-mail]  (SCATTOLIN patrice)
Subject: Wanted: images of craters or other surfaces


Hi,

 I am currently taking an image processing course and have a project
on the "shape from shading" method of recovering surfaces. It is my
understanding that this method works well with images of craters or
other such things with hole and hills that are made on one material.

   I am looking for GRAY LEVEL images that would loosly fit the
above description. I would like to know where I could get such images
(ftp or e-mail I don't have too much time).  I have no access to
a CD-ROM and I only want few images (only a class project not a thesis).

   Please reply via e-mail to

    [e-mail]





------------------------------------------------------------------------
Patrice Scattolin            [e-mail]
Concordia University            Montreal, Canada
"I live so far north that Santa lives two blocks from me"

------------------------------

Date: 25 Feb 90 04:17:34 GMT
From: mcgill-vision!clyde.concordia.ca!sherlock![e-mail]  (SCATTOLIN patrice)
Subject: Wanted: images of craters or other surfaces


Hi,

 I am currently taking an image processing course and have a project
on the "shape from shading" method of recovering surfaces. It is my
understanding that this method works well with images of craters or
other such things with hole and hills that are made on one material.

   I am looking for GRAY LEVEL images that would loosly fit the
above description. I would like to know where I could get such images
(ftp or e-mail I don't have too much time).  I have no access to
a CD-ROM and I only want few images (only a class project not a thesis).

   Please reply via e-mail to

    [e-mail]





------------------------------------------------------------------------
Patrice Scattolin            [e-mail]
Concordia University            Montreal, Canada
"I live so far north that Santa lives two blocks from me"

------------------------------

Date: 25 Feb 90 10:30:46 GMT
From: unmvax!nmtsun![e-mail]  (Daniel Briggs)
Subject: Re: NASA Prediction Bulletins

In article <[e-mail]> [e-mail] (TS Kelso) writes:
>lots of orbital element stuff

Here's a question for all you statellite jockeys:  What programs do you use
to reduce your NASA orbital elements into local azimuth & elevation for
pointing a telescope?

A while ago, I had to find a geosynchronous communications satellite for the
purpose of measuring a beam shape.  I poked around a bit for such a program
and didn't find one, so I wrote my own.  Since then, I have come across a
couple of others, all written by people much like myself.  That is, I tried
to take most of the obvious first order effects into account, (like a standard
geoid for the earth surface, etc.), but there is no telling if I got them
right.  In any event, my code worked well enough for me to find my satellite,
so I was happy.  The problem is that all of these "casual" orbital element
programs disagree among each other to the tune of tens of arc minutes or more.
I would really like to get my hands on one that eats NASA elements and spits
out local az & el, and that was written by a real professional in the field.
Ideally it would use a fairly accurate earth model, and at least a first
order approximation to a dry atmosphere.  That sort of a program shouldn't
have any difficulty in predicting to under an arc minute, I should think.
(Then again, I don't know how accurately the orbital elements are measured in
the first place.  Any one else know?)  This sort of accuracy is in fact fairly
useful to me, since the telescope in question has a beam of less than an
arc minute at its highest frequencies.  It would be convenient to hit a
satellite without having to hunt for it first.

(As you can tell, we are not often interested in finding satellites.  Most
often we are interested in avoiding them ;-)

-----
This is a shared guest account, please send replies to
[e-mail] (Internet)
Dan Briggs / NRAO / P.O. Box O / Socorro, NM / 87801  (U.S. Snail)

------------------------------

Date: 25 Feb 90 20:33:19 GMT
From: snorkelwacker!usc!cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!watserv1!watdragon!watyew![e-mail]  (Brian or James)
Subject: Re: New private home satellite network


 I could see some governments having *no* problem at all using
'immoral' broadcasts from within sovereign nations as a justification
for invasion. Actually, it could be a political treasure for the
invading government, since any opposition to the act would have to
risk appearing to be in favour of the 'immoral' broadcasts in question,
whether or not the primary motive for invasion had *anything* to do with
the broadcasts (I'm thinking mainly of the issue of drugs in the recent
US invasion of Panama, since there are nations that export a far larger
tonnage of illicit chemicals to the US whose governments have not irritated
the US politically, and haven't been invaded recently, either. Drugs
make an even better justification for intervention than Communism did,
since while some people will willingly identify themselves with the
'Left', no-one wants to be seen defending drug use). Were I paranoid,
I could even see various governments setting up the offending broadcasters
in the first place, just to have an acceptable reason to intervene abroad.
Of course, that's silly, since it would be like dressing corpses in the
uniform of a neighboring country and claiming they are causualties in a
sneak attack on the Homeland, or sinking a naval vessel in a foreign port.
                                           JDN

------------------------------

Date: 24 Feb 90 23:27:48 GMT
From: attcan!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Fun Space Fact #1: Launcher Development Costs (long)

In article <[e-mail]> [e-mail] (Todd Johnson) writes:
>> [laser launchers]
>> ... Payload to orbit was something like 20kg...
>
>20 kg? If that's not a typo, such a low load would probably require
>on orbit assembly (worse, tugging stuff up to GEO or higher orbits
>would probably be required which means either a refuellable tug
>or a throwaway transfer vehicle). It's not clear to me that you've
>saved anything with such a low payload. Are you sure it wasn't more
>like 20,000 kg? or 2,000 kg?

It was 20 kg.  Laser-launcher size, hassle, and capital costs are directly
proportional to the size of the payload and almost completely independent
of launch frequency, which strongly encourages lots of small payloads
rather than a few large ones.  On-orbit assembly is thus a requirement;
what's so bad about that?  It's probably possible to build a 20kg assembly
tug that can do much of the work, last I heard.

And yes, moving stuff up to higher orbits requires a tug or upper stage
of some kind, but that's the sensible way of doing things anyway.  Remember
that a laser system which can put payloads into orbit may be able to do
much of the work of boosting stuff into higher orbits.  (Depending on the
orbit, it may not be able to do the apogee burn, but the perigee burn is the
big one anyway.)

As for what you've saved, to put it bluntly:  lots of money.  The added
complexity is swamped by the lower launch costs.
--
"The N in NFS stands for Not, |     Henry Spencer at U of Toronto Zoology
or Need, or perhaps Nightmare"| uunet!attcan!utzoo!henry [e-mail]

------------------------------

Date: 26 Feb 90 02:50:52 GMT
From: cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Fun Space Fact #1: Launcher Development Costs (long)

In article <[e-mail]> [e-mail] writes:
>>> The USAF's demands for a bigger orbiter with more cross range
>>> increased the size of the bird considerably but didn't affect
>>> complexity much.
>
>A much bigger and more capable bird (at least in theory) built at
>the same degree of sophistication would seem to me to indicate a
>much more 'complex' vehicle, with a commensurate increase in
>processing time between flights.  After all, NASA couldn't just make
>all the parts bigger.

No, but they could build much the same thing on a slightly larger scale.
Things like the electronics wouldn't have to be scaled at all.  There
is no inherent reason why a bigger vehicle has to be more complex.

>And even if it were possible to just scale up everything (which I've
>been assured is almost never the case), you're still greatly
>increasing the stresses on the parts, and it would still require
>much more processing.

I must have missed something here -- why does being bigger automatically
imply operating with smaller safety margins, nearer the limits of the
parts?  If it doesn't, why "greatly increasing the stresses" and "much
more processing"?  You'll have to explain this one.

>...mention something about it being much easier to design, build, and
>maintain smaller liquid hydrogen engines than it was larger ones,
>which was why one usually saw hydrogen fueled stages appear as the
>smaller upper stages of boosters first.

Um, you've misunderstood what I said (it was me).  The reason why people
start small with hydrogen engines is the same reason why engineers start
small in almost any new technology:  smaller hardware is cheaper to build
and debug, so you try to make your learning-phase mistakes on a small
scale.  There is no inherent complexity gain as the engines get bigger.

>I guess we're just going to have to disagree on this one.  Seems to
>me that servicing a smaller vehicle with fewer parts taking less
>stress would reduce it significantly...

I have no quarrel with that, but you haven't justified your assertions
that smaller size means fewer parts and less stress.

>>> promises have been scaled back again and again to "match" the available
>>> funding, and NASA hasn't been able to meet them, ever.  The problem is
>>> fundamental, not an accident of a funding shortage at a particular time.
>
>Welcome to the 'real world' of cost estimating, budget and schedule
>projection, and marketing...

Actually, welcome to the "real world" of agencies that have been in
business too long.  The problem is *not* fundamental to the budgetary
process, given competent people who are motivated to deal with it
well, as witness some of the things that are occasionally accomplished
under the current budgetary process (notably by SDI, which hasn't had
time for its arteries to harden).  The problem *is* fundamental to today's
NASA, and nothing short of massive reform is going to cure it, I'm afraid.

>... If something is scheduled to take 9 man-months when worked on
>by an individual, you can't finish it in a month by throwing 9
>people at it.  Neither can you replace the payloads of 10 40,000
>pound launches with 200 launches of 2,000 pound payloads, unless
>your sole yardstick is the amount of mass in orbit...

Certainly not; you have to rethink the payload design around splitting
it up into pieces (bad) and not requiring the connections to survive
launch stresses (good).  As I've said before, people who have studied
this tradeoff closely tend to conclude that the split is a net win.
This is emphatically true if the small launches cost a whole lot less.

>>> I dimly recall a design sketch from Jordin Kare's group for a laser
>>> launcher costing about half a billion dollars that could launch more
>>> than the entire shuttle fleet, for that matter.
>
>Great!  Let's build it!

Sounds like a great idea to me, and probably to Jordin.  Are *you* going
to provide the money?

>>> It takes *one* of those 2000-pound launches to add a human to the
>>> collection of payloads comprising a mission.
>
>And how long is your man-in-a-can's life support good for?  ...

Mercury, using 1950s technology, got several days (with never-realized
plans to extend it to a week or more) for one man with 3000 pounds.
I'd hope we could do a little better today.

>>> Be generous and add one more for a little tug to bring the pieces
>>> together (there are tug designs a lot smaller than 2000 pounds).
>
>Maybe you'd better be a little more generous, and add more than one
>human and more than one tug, along with rather more extended
>life-support and some fuel to chase the pieces with...

Why do we need multiple tugs and multiple people?  And I was figuring
2000 pounds fully fueled, by the way, so no need to budget extra for
that.

>Now add enough propellent and life-support for your single man to
>chase down 20 pieces and push them all together, fasten them, etc.

Why does he have to do the chasing?  We do that in advance, from the
ground, with remote control for the tug.  All he has to do is assembly.
He's got several days to plug 20 pieces together.  Sounds manageable.

>I remember when the 'conventional wisdom' was that it took at least
>3 stages to get a reasonable payload to orbit.  And I'm not that
>old...

Um, Grandpa, that was disproven decisively in 1961, when the first orbital
Mercury launch went up on a 1.5-stage Atlas.  (Possibly earlier, this is
the first major Atlas payload I know of -- small ones went up starting
in 1958, but I'm not sure when the heavy loads started.)  How old did you
say you were? :-)  NASA ran a wide spectrum of orbital and planetary
missions in the early-mid 1960s using two-stage boosters (Titan II,
Atlas-Agena, Atlas-Centaur).  Only one US manned Earth-orbit flight has
ever used three stages, and that was because an Apollo with LM was a bit
too heavy to use a Saturn IB for Apollo 9.
--
"The N in NFS stands for Not, |     Henry Spencer at U of Toronto Zoology
or Need, or perhaps Nightmare"| uunet!attcan!utzoo!henry [e-mail]

------------------------------

End of SPACE Digest V11 #82
*******************