Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v11_0/v11_073.txt

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Date: Fri, 23 Feb 90 01:33:49 -0500 (EST)
Subject: SPACE Digest V11 #73

SPACE Digest                                      Volume 11 : Issue 73

Today's Topics:
       Re: Fun Space Fact #1: Launcher Development Costs (long)
           Re: Why we would need a planet.
      Re: Fun Space Fact #1: Launcher Development Costs
        Re: New private home satellite network
              Re: Voyager and relativity
          New private home satellite network
       Re: Did SEASAT See More Than It Was Supposed To?
       Re: Fun Space Fact #1: Launcher Development Costs (long)
               Re: Spacecraft on Venus
            Re: metric vs. imperial units
       Re: Fun Space Fact #1: Launcher Development Costs (long)
----------------------------------------------------------------------

Date: 21 Feb 90 16:06:50 GMT
From: pacific.mps.ohio-state.edu!zaphod.mps.ohio-state.edu!rpi!crdgw1!sixhub![e-mail]  (Wm E. Davidsen Jr)
Subject: Re: Fun Space Fact #1: Launcher Development Costs (long)

In article <[e-mail]> [e-mail] (Henry Spencer) writes:

| "Many hundreds"?  Where do you get "many hundreds"?  It doesn't take
| that many 2000-pound launches to equal the entire capacity of the
| current shuttle fleet (which is, optimistically, ten 40000-pound
| launches per year).  That's about a launch a day, which is not that
| far from what the Soviets can do now if pushed.

  It's not clear what the overhead of doing physically large (not just
heavy) things like LDEF would be. Since we have limited experience in
building large and complex things in space, I don't trust approximations
of how much overhead would be added to do assembly.

  I hope that we will soon have some light launch capability outside of
NASA, I just wish I could believe that we will have a heavy lauch
capability.
--
bill davidsen - [e-mail] (uunet!crdgw1!sixhub!davidsen)
    sysop *IX BBS and Public Access UNIX
    moderator of comp.binaries.ibm.pc
"Getting old is bad, but it beats the hell out of the alternative" -anon

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

Date: 22 Feb 90 18:41:44 GMT
From: zephyr.ens.tek.com!wrgate!mrloog![e-mail]  (Dan Tilque)
Subject: Re: Why we would need a planet.

[e-mail] (Jonathan Leech) writes:
>
>    So strip off the outer kilometer of the planet, move it to the
>inside of a cylinder, and spin it up to 1 G.

Is this an attempt to make Mercator projections accurate?  Or maybe the
orange peel maps?  Do we stretch the higher latitudes or leave gaps?

---
Dan Tilque    --    [e-mail]

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

Date: Thu, 22 Feb 90 13:58:11 CST
From: [e-mail]
Subject: Re: Fun Space Fact #1: Launcher Development Costs

>> is "agate![e-mail] (William Baxter)"

>> In article <[e-mail]>, mccall@skvax1 (Constitutional
>> rights? We don't need no stinking Constitutional rights!) writes:
>> >                    the Shuttle "doesn't work very well".
>> >What this really means, of course, is that the Shuttle isn't what it
>> >was billed as when the money for it was justified to Congress.  But
>> >then, it was Congress that kept cutting back the funding for it,
>> >wasn't it?

>> This is one of the myths that constantly circulates among space
>> pacifists.  If only Congress gave NASA enough money everything would be
>> fine.

Except, of course, that that isn't what I said.  I do think,
however, that ignoring the impact of the budgetary process on what
we finally wound up with in the way of a Shuttle is a particular
form of self-imposed blindness for some people.  As is, it would
appear, assuming that any disagreement with their opinions
automatically means that the person disagreeing must have whatever
their particular generalized stereotype for the attitudes of 'the
enemy' is.

>> The reason this myth persists is that too many people accept this
>> statement as fact without checking the facts.  Go read the congressional
>> record around the time of the original shuttle appropriations.  In
>> particular, look for questions by Rep. Karch from Minnesota.  NASA made
>> absurd predictions about what the shuttle would do and how much it would
>> cost.  (they are recycling some of their original claims in support of
>> NASP)

Yes, and if one really looks one can also find things about what
NASA originally wanted to build, which has been mentioned by both
Henry Spencer and myself.  Why do you suppose that that original
system wasn't built, Mr. Baxter?  Because NASA is a bunch of evil
people who just want to rip off the American taxpayer?  Hardly seems
credible, to me.

Ignoring the impacts of the budgetary process on plans and desires
is also one of those interesting blind spots.  Other than that, of
course, and the remarks which I assume are intended to chastise me
for having the temerity to disagree with his disciple and himself,
I pretty much agree with what Mr. Baxter says here.

This sort of behaviour, taking what can be gotten and stretching
justifications, schedules, costs, etc.  via overly optimistic
projections in order to get it is a lamentable failing of the way
business is done, but the problem hardly originated with NASA, nor is
it restricted to them.  It's caused by the way the budgetary process
works (or doesn't work).

It will also not be solved by just 'bashing' them for it.  If you
want to do something to correct it, start at the top where such
attitudes are engendered, and that means starting with the Congress
and the way the budgetary process is run (or not run) from the top.

>> Check your facts *before* you post.  You might even need to read an
>> article twice: first to find out what it says, and again to respond
>> *after* going away to check the facts.  This is of course contrary to
>> the spirit of newsgroup reading, which is normally an exercise in
>> eye-hand coordination bypassing the remainder of the brain.

Good advice, which it seems that Mr. Baxter should perhaps have
considered following himself.

>> William Baxter
>>
>> ARPA: web@{garnet,brahms,math}.Berkeley.EDU
>> UUCP: {sun,dual,decwrl,decvax,hplabs,...}!ucbvax!garnet!web


==============================================================================
| Fred McCall  ([e-mail]) | My boss doesn't agree with anything  |
| Military Computer Systems           | I say, so I don't think the company  |
| Defense Systems & Electronics Group | does, either.  That must mean I'm    |
| Texas Instruments, Inc.             | stuck with any opinions stated here. |
==============================================================================

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

Date: 22 Feb 90 16:14:12 GMT
From: shlump.nac.dec.com![e-mail]  (Gary Hughes - VMS Development)
Subject: Re: New private home satellite network

In article <[e-mail]>, [e-mail] (Brad Templeton) writes...
>NBC and some other cable/media companies are launching a home satellite
>network.  Private 18 inch dish which is easy to install, 102 channels,
    .
    .
>What if a private concern, based on some lax-law island, were to get
>together $300 million an launch one of these things?   They could start
>completely uncensored, unregulated TV -- assuming they got somebody
>(the Chinese?) to launch it.

In a sense this has already happened, with Rupert Murdoch's DBS plans for the
UK. This will use Astra and is therefore not under control of the UK
broadcasting authorities. Rupert has promised to be a good boy.

Interestingly, Murdoch was part of the Sky Cable announcement, as was Hughes
Communication. My guess is that it will be considered a US domestic comsat,
subject to US law.

Gary Hughes
hughes @star.dec.com

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

Date: 22 Feb 90 16:49:43 GMT
From: elroy.jpl.nasa.gov!usc!cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Voyager and relativity

In article <[e-mail]> [e-mail] (Peter G. Ford) writes:
>Just for fun, here is a partial list of some of the phenomena that
>are modeled in a high-quality space tracking program:

Folks who are interested in this sort of thing might want to hit your local
technical library and read the Oct 1985 issue of the Journal of the British
Interplanetary Society, which was a special issue on mission operations --
navigation, communications, software, etc. -- full of papers from JPL.
--
"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: 22 Feb 90 07:52:02 GMT
From: maytag!looking![e-mail]  (Brad Templeton)
Subject: New private home satellite network

NBC and some other cable/media companies are launching a home satellite
network.  Private 18 inch dish which is easy to install, 102 channels,
all digital, HDTV and more -- cost around $300/year, plus $250 for
dish.

In other words, cable is dealt a serious blow.  A totally new network
with none of the old trappings.

It's all done with a rather expensive, very high power comsat.

Many writers have talked about private TV that is completely beyond the
reach of governments.  This could make it a serious reality.  Satellite
reception in just about any home.

What if a private concern, based on some lax-law island, were to get
together $300 million an launch one of these things?   They could start
completely uncensored, unregulated TV -- assuming they got somebody
(the Chinese?) to launch it.

What would happen?  Would governments let it be?  Would they try to jam
it?  Shoot it down?  Is there any sort of space law or space treaty that
would govern something like this?

Of course, space in geosync orbit is limited.  There may be one light second
of circumference out there, but it's really only 2PI radians, and in
particular, much less within view of North America.  This is a resource
that will soon become scarce.  I wonder what people will do about it?
--
Brad Templeton, ClariNet Communications Corp. -- Waterloo, Ontario 519/884-7473

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

Date: 21 Feb 90 18:30:16 GMT
From: zaphod.mps.ohio-state.edu!samsung!aplcen!aplvax.jhuapl.edu![e-mail]  (Jim Meritt)
Subject: Re: Did SEASAT See More Than It Was Supposed To?

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
}In article <[e-mail]> [e-mail] (John A. Weeks III) writes:
}>    ... it showed things in the world's oceans
}>    that the Navy neither expected nor wanted to
}>    have shown."
}>
}>Does anyone know exactly what is being alluded to here?

To make a guess from unclassified, public data I'd guess Kelvin wakes.
Note:  I have not looked at any information directly concerning SEASAT
that is classified and relates to this conclusion.

}Seasat radar images definitely showed detailed features of the sea bottom
}in shallow areas.  This was thought to be the result of bottom features
}affecting the shape of the sea surface -- the radar beam definitely does
}not penetrate seawater to any significant extent, last I heard.  The
}question is, can you find a submerged submarine that way?  There has
}been much speculation, but as far as I know there has been no definitive
}answer from people in a position to know.

Henry, the shaping of the geoid (outlining the bottom contours on the
surface shape) has nothing to do with the depth.  Works nicely everywhere.
Trenches look neat.  However, I see no way for that mechanism to be used
to detect neutrally boyant objects.

That that is is that that is. That that is not is that that is not.
That that is is not that that is not.  That that is not is not that that is.
And that includes these opinions, which are solely mine!
[e-mail]  - or - [e-mail]  - or - meritt%aplvm.BITNET

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

Date: 22 Feb 90 00:05:18 GMT
From: [e-mail]  (SERRE GLENN)
Subject: Re: Fun Space Fact #1: Launcher Development Costs (long)

In article <[e-mail]> [e-mail] (bill davidsen) writes:

>  I hope that we will soon have some light launch capability outside of
>NASA, I just wish I could believe that we will have a heavy lauch
>capability.
>--
>bill davidsen - [e-mail] (uunet!crdgw1!sixhub!davidsen)

So what are Titan IV and Commercial Titan, chopped liver?  They both have
payload weights that are just a little lighter than the shuttle.  Future
enhancements (currently in te developement stage for Titan IV, at least) will
boost those weights to more than the shuttle's.  Further, Titan
can launch Centaurs.

--Glenn Serre
[e-mail]

--PS, this is not meant to imply that I consider the shuttle payload
capability to be particularly heavy.  The Saturn V was able to launch
?265,000lbs.? into LEO.

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

Date: 21 Feb 90 16:45:44 GMT
From: cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Spacecraft on Venus

In article <[e-mail]> [e-mail] (N = R*fgfpneflfifaL 20-Feb-1990 1302) writes:
>        What would it take - in terms of alloys, etc. - for a manned
>    spacecraft to survive on the planet Venus?  ...

The chemical problems are manageable.  The real problem is not alloys,
but building the most ferociously capable heat-pump system you ever saw,
to pump heat out faster than it can leak in.  Not impossible, but a major
engineering challenge.
--
"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: 21 Feb 90 15:39:03 GMT
From: snorkelwacker!usc!zaphod.mps.ohio-state.edu!rpi!crdgw1!sixhub![e-mail]  (Wm E. Davidsen Jr)
Subject: Re: metric vs. imperial units

In article <[e-mail]> [e-mail] (Mike Peltier) writes:

| When you start getting funky numbers going into a calculation, such
| as 5280, 12, 212, 32, etc, instead of 1000, 10, 100, 0, etc, you start
| introducting the potential for computational errors caused by the facts
| that computers can only represent numbers with limited significance,
| and use mantissa/exponent notation.

  And since powers of ten aren't powers of two, in a binary computer
they are approximated, too.

  The only good thing about metric is that you don't have to memorize
the ten or so numbers which convert units in imperial. The bad thing is
that even people who grew up with it occasionally say centimeter when
they mean milimeter. I have never seen that with inch and foot, or yard,
or mile. They *sound* similar, and somehow that seems to lead to a slip
of the tongue.
--
bill davidsen - [e-mail] (uunet!crdgw1!sixhub!davidsen)
    sysop *IX BBS and Public Access UNIX
    moderator of comp.binaries.ibm.pc
"Getting old is bad, but it beats the hell out of the alternative" -anon

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

Date: 22 Feb 90 23:01:22 GMT
From: cs.utexas.edu!usc!elroy.jpl.nasa.gov!turnkey!orchard.la.locus.com!prodnet.la.locus.com![e-mail]  (Todd Johnson)
Subject: Re: Fun Space Fact #1: Launcher Development Costs (long)

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>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.

Henry, what were the anticipated spacecraft loads with the laser
launcher? Very high g loads would require a greater structural
mass although this trades off against lower launch costs. At
some point it gets more expensive to use a high g launcher than
even the Shuttle.

>Actually, not much.  It is verifiably easy to launch modest payloads
>with 1950s technology.
> The technologies that really matter, notably propulsion, have
>been just about completely stagnant.  And Amroc (and the other small
>launch companies) by and large are not using leading-edge technology,
>because that's a good way to spend billions.

NASA's brief for many areas is to push technology. They do it with
aircraft (where we get all those lovely NACA/NASA airfoils) and they
did it with rocketry (from the start to the present). Many people
have built rockets with lessons learned from NASA (Buran does look
strangely familiar).

I would argue also that slush hydrogen, resistojets, arc-jets, ion
propulsion, high density matter and the aerospace plane are all
new technologies since the '50's and NASA has had some positive
impact on all of them.

I don't really think that propulsion technology has stagnated in
the States, it's just become more classified.

NASA's biggest and continuing problem is that its space organization
has been forced to meet conflicting goals on minimal budgets: perform
scientific exploration; push technological limits; be cost effective;
turn a profit; do it in zero time. Those problems have built within
the space part of the organization a certain battle-weary bureaucracy
that has been taught by the Pavlovian application of political indifference
to be conservative in all areas. NASA's current and future condition
is solely due to the American people. I also think that NASA of all the
space agencies extant (Japan's, Russia's, Europe's, China's) is the
one most affected by its nation's populace.
--
lcc![e-mail]
{randvax,sdcrdcf,ucbvax}!ucla-se!lcc!todd
{gryphon,turnkey,attunix,oblio}!lcc!todd

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

End of SPACE Digest V11 #73
*******************