Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V13_3/V13_355.TXT

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Subject: SPACE Digest V13 #355

SPACE Digest                                     Volume 13 : Issue 355

Today's Topics:
                Re: Mt. Venus
                Re: "Follies"
             This Nuclear Rocket Thing...
            SPACE Digest V13 #349
                Re: Mt. Venus
     Re: Chemical rocket complexities (was Re: "Follies")
              Re: More cost/lb. follies
              Re: More cost/lb. follies
             Increasing value/lb.

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

Date: 4 Apr 91 02:07:15 GMT
From: prism![e-mail]  (Matthew DeLuca)
Subject: Re: Mt. Venus

In article <[e-mail]> [e-mail] writes:
>
>Last night I watched a show about Venus that got me thinking.  Now as all of us
>know the pressure on Venus is incredible (90 times that of earth) and the
>temperature is nearly as bad (900F).  The show mentioned that Venus had a
>mountain that was 30,000ft tall (1.5 times as tall as Mt. Everest).

Just to be picky, Mt Everest is 29,029ft tall.  I believe the largest mountain
on earth, measured from base to summit, is Mauna Kea, in Hawaii, at some
33,000ft.

--
Matthew DeLuca
Georgia Institute of Technology      "I'd hire the Dorsai, if I knew their
Office of Information Technology      P.O. box."  - Zebadiah Carter,
Internet: [e-mail]    _The Number of the Beast_

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

Date: Wed, 3 Apr 91 08:30:33 -0500
From: "Allen W. Sherzer" <[e-mail]>
Subject: Re: "Follies"
Newsgroups: sci.space
Cc:

In article <[e-mail]> Henry Spencer writes:
>ALS's biggest problem, though, is the same one that bedevils any big-launcher
>project right now:  where's the market?

That is a big problem but look at it another way: maybe the existance of
a cheap launcher of any type (SSX or HLV) will stimulate a market. Von Braun
began development of the F-1s long before the call to go to the moon. He
said to himself 'someday we will need a BIG engine'. Had he not done that,
Apollo wouldn't have made it's end-of-decade deadline.

Now I don't think ALS is that launcher but between HL Delta, Titan V, and
new F-1s we see that it can be built. Would it create new markets? Not for
a while. What it would do would be to undercut Arianspace and help the US
regain market share. Eventually the factor of three reduction would open
new markets.

The key however is to use what we have today and procure commercially.

  Allen

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

Date: 3 Apr 91 20:32:42 GMT
From: mojo![e-mail]  (Doug Mohney)
Subject: This Nuclear Rocket Thing...

Most amusing! I think NASA would take a serious look at it (well, *is* taking a
serious look at it). Av. Week had a wonderful article a couple of weeks back on
various proposals for a nuclear engine. It could cut travel time to Mars by
anywhere from 1/3 to 2/3s the time and having that power there allows for MUCH
more flexable abort options.

Major thrust of the article was to use nuclear energy to <ha!> cut down on the
exposure of astronauts to background radiation during their travels to/from
Mars. One Solar Flare could ruin your whole day...

            DM


     Signature envy: quality of some people to put 24+ lines in their .sigs
  -- >                  [e-mail]                        < --

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

ReSent-Message-ID: <[e-mail]>
Resent-Date:  Wed, 03 Apr 91 12:09:47 EST
Resent-From: Tom McWilliams <[e-mail]>
Resent-To: [e-mail]
Date:         Wed, 3 Apr 91 03:17:07 EST
Reply-To: [e-mail]
From: [e-mail]
Subject:      SPACE Digest V13 #349
Comments: To: [e-mail]
To: david polito <[e-mail]>, Tom McWilliams <[e-mail]>

Re: Eclipses

>>Has the sun's corona been observed above the Earth's atmosphere?  If not,
>>isn't possible that it is merely an atmospheric phenomenon, just light
>>scatering and refracting around the edges of the moon.

>No the Corona is a real part of the sun caused by light emitted and reflected
>by particles that are continuously streaming away from the sun.
>(refracting around the sun ? HOW?)

I think the mechanism was supposed to be diffraction, not refraction.
But the answer is still no.

Also, the corona has been observed by the creation of fake eclipses.

Tommy Mac       "Is he insulating his office with magazines?"
18084tm@msu          -my girlfriend, after seeing where my boss works.
Acknowledge-To: <18084TM@MSU>

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

Date: 4 Apr 91 03:00:31 GMT
From: sun-barr!newstop!exodus!concertina.Eng.Sun.COM![e-mail]  (Steve Hix)
Subject: Re: Mt. Venus

In article <[e-mail]> [e-mail] (Matthew DeLuca) writes:
>In article <[e-mail]> [e-mail] writes:
>>
>>Last night I watched a show about Venus that got me thinking.  Now as all of us
>>know the pressure on Venus is incredible (90 times that of earth) and the
>>temperature is nearly as bad (900F).  The show mentioned that Venus had a
>>mountain that was 30,000ft tall (1.5 times as tall as Mt. Everest).
>
>Just to be picky, Mt Everest is 29,029ft tall.  I believe the largest mountain
>on earth, measured from base to summit, is Mauna Kea, in Hawaii, at some
>33,000ft.

But Everest (Chomlungma?) cheats! It sits on on a 14,000' plateau.  Mt. Denali in
Alaska is higher, base-to-peak, sitting nearly at sea level.




--
------------
  The only drawback with morning is that it comes
    at such an inconvenient time of day.
------------

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

Date: 1 Apr 91 22:05:31 GMT
From: unisoft!fai!sequent!crg5![e-mail]  (Nick Szabo)
Subject: Re: Chemical rocket complexities (was Re: "Follies")

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>
>The big one is not technical but organizational:  they all (even Pegasus,
>although not to quite the same extent) are built based on military missile
>technology by missile-technology organizations,

Shuttle?  Delta?  Scout?  Ariane?  H-1?

Of course, chemical rockets _are_, when all is said and done, military
missile technology -- this has been the dominant use in their 1,000+ year
history.   They are quite suitable as missiles, and have proven only
marginally suitable for orbital launches, at high costs and very low
reliability.  While we're changing the organization, let's also try
changing the technology to something that has been fundamentally designed
for the task, instead of crudely retrofitted.


>...to whom cost is no object...the current customer base sees nothing
>wrong with that. They are complex and costly because nobody has seriously
>tried to build one simple and cheap.  Nobody has tried because the customers
>haven't asked for it.

Listen to yourself, Henry.  I suppose you always shop for
gas at the highest-price station, and throw in a tip to boot?
You accept whatever price the car salesman offers, and let's throw
in _all_ the options, thank you so much.  Sheesh.

Yes, Henry, it's true: NASA, DoD, and satcom operators have been
yelling as loud as space fans for years for lower launch costs, with
the same end effect.   Shuttle, ALS, Ariane, H-1, all designed from
scratch, both technologically and organizationally, to lower cost/lb.,
all failed or failing miserably at this goal, because they used the
same old chem rocket technology.


>The customers haven't asked because their payloads
>cost far more than the launches,

This is sort of like expecting truck customers to ship sand instead
of machinery, in the hope that trucking costs will go lower.  The
payload/transport cost ratios for launchers (1/1-5/1) are as low as
they get for a transportation system.  A more normal range is
10/1-100/1.  Payload/transport cost ratios are already as low as they are,
due to the incredible unreliability of rockets and the accompanying
insurance rates.

This sort of thinking really demonstrates just how stretched and
desparate the rocket launch cost situation really is.  If there really
was room for technological or organizational improvement, we would be
working on that instead of placing such incredible blame on customers
that have already bent themselves way out of shape to live with the
idiosynchricies of chem rockets.


>so launch costs are relatively unimportant
>and reliability (that is, use of well-proven existing launchers) is vital.

Since when has transportation reliability ever been unimportant?
Please, study up on, and think about, the economics of transportation
systems before coming up with these wild theories of payload costs,
customer motivation, and organizations.  Of course, rocket fans get really
pissed when the question of reliability comes up, because chem rockets
simply cannot deliver the reliability of a normal transportation system, at
any price.  Thus the outrageous insurance premiums, and the emphasis
of customers on reliability as well as cost/lb. and other factors all
important to a true transporation system.

This blame the customer routine will only hasten the demise of
chemical rockets, since no customer is willing to put up with such a
perverse attitude for long.  Customers will start looking for choices --
EML, gas gun, and laser launch will start looking worth the R&D, even over
the short term.  Even high up-front costs (although lower than the costs
of the larger chem rocket projects) are preferable to people who don't
understand your needs and have such a narrow view of what constitutes
a transportation system. Anybody who really cares about getting their
payloads into space, be you astronomer or satcom operator or would-be
space colonist, take careful heed of the rocket community's definition
of "transporation".  It is time to start looking for a truly efficient,
truly reliable way to get into space.



--
Nick Szabo            [e-mail]
"If you want oil, drill lots of wells" -- J. Paul Getty
The above opinions are my own and not related to those of any
organization I may be affiliated with.

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

Date: 3 Apr 91 00:27:32 GMT
From: mips!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!emory!wa4mei!ke4zv![e-mail]  (Gary Coffman)
Subject: Re: More cost/lb. follies

In article <[e-mail]> [e-mail] ("Allen W. Sherzer") writes:
>
>In article <[e-mail]> Nick Szabo writes:
>>First, this configuration has not flown yet.
>Come now Mr. Szabo, this is a conservative use of a well understood
>technology. Using those numbers is perfectly valid.

Well this well understood technology just went blooey on the test stand.
Nice pictures on CNN.

Gary

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

Date: Wed, 3 Apr 91 09:15:05 -0500
From: "Allen W. Sherzer" <[e-mail]>
Subject: Re: More cost/lb. follies
Newsgroups: sci.space
Cc:

In article <[e-mail]>:

>>>First, this configuration has not flown yet.
>>Come now Mr. Szabo, this is a conservative use of a well understood
>>technology. Using those numbers is perfectly valid.

>Well this well understood technology just went blooey on the test stand.

Every now and then any technology goes blooey. I'll bet money that this
accident has only minor impact on the program schedule.

We have been building solid motors for a long time and it is well understood.

  Allen

--
+-----------------------------------------------------------------------------+
|Allen W. Sherzer | If you love something, let it go. If it doesn't come back |
|   [e-mail]   | to you, hunt it down and kill it.                         |
+-----------------------------------------------------------------------------+

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

Date: 1 Apr 91 20:37:31 GMT
From: unisoft!fai!sequent!crg5![e-mail]  (Nick Szabo)
Subject: Increasing value/lb.

In article <[e-mail]> [e-mail] (Tommy Mac) writes:

>If the goal is building a space-mining-infrastructure (a very GOOD goal, IMHO)

Space mining & manufacturing are indeed the critical path technologies of
exporting space industries and space colonization.


>then it should be obvious that SOME kind of rocket will be needed in large
>volume.  At least for crew carrying, if nothing else.

Not necesarilly.   The alternative to costly, environmentally damaging
high volumes is increasing value/lb.  In fact, we have been making much
more progress increasing value/lb. than decreasing cost/lb, even though
the space community has placed less emphasis on this important variable.
It has taken new technolgoy and cleverness, and it will take quite a bit
more, but there is no shortage of these when we let our minds take in the
whole picture instead of focusing on a single narrow variable.  The
following technologies/knowledge sets are progressing much more rapidly
than chem rocket launch costs:

* astronomy:

Knowledge of what & where resource are.   As recently as the 70's,
we were stuck thinking the Moon was the only convenient resource.  Now,
through orbital mechanics and the observations of a handful of
astronomers,  we know that asteroids and comets can give us an order of
magnitude or more improvement in convenience and variety over the lunar
surface.   Despite lack of attention and funding, we are rapidly discovering
more, and devising was to retreive these resources by letting the solar
system do the work for us (eg gravity maneuvers, aerobraking, solar power,
etc.) The more I get into the details of space colonization, the more I
realize the massive gains to be made simply from increasing our knowledge of
where it is we intend to go.

* robotics

Japan has gone from a few dozen specialized robots to tens of thousands in
little over a decade, with the West reluctantly following suit.  However,
MIT is devising a new generation of "insect robots" that will obsolete
the previous generation.   Where labor is expensive (eg space, where it
costs $1,000,000/hr.), we will soon have automation to the point where
most mining and manufacturing tasks can be performed by automated and
teleoperated facilities.

* teleoperation

JPL has demonstrated the ability to perform complex maneuvers
even across several hours of round-trip light-time.  Meanwhile, more
real-time teleoperation has made great strides, for example in deep-ocean
exploration and salvaging.  Virtual reality has gone from nothing to very
convincing prototypes in ten years, and will soon be hooked up to sea-
and space-borne teleoperators.

* computation

Both robotics and teleoperation have benefitted greatly from the
c. 3 orders of magnitude improvement in computation since Apollo,
and this pace continues, with the end nowhere in sight (cf. new
50 MIPS computer from HP, and multiprocessing).

* communications

The bandwith of the DSN system has quadrupled in a decade, and this with
no new antennas, merely retrofitting the old technology.   New radio
bands and optical bands have the potential for 5 or more orders
of magnitude improvement.  These advances are also opening up brand new
markets, such as the phone cell satellite market being developed by Iridium.
Circuit density on satcoms is doubling every decade.

* microdevices/nanotechnology

Custom VLSI, atom-by-atom writing, and hair-sized motors were
inconceivable even well after Apollo.  By early in the next century,
these will be commonplace for spacecraft.

* thin-film vapor deposition

Civil engineering in free space is a whole new beast.  Throw out all
the rules of structure based on gravity; space structures can do the
spider one better.   Many of the strucutures we will need, including
mirrors, shades, and even pressure hulls, can be vapor deposited using
techniques borrowed from earth-side vacuum chambers, but scaled up
many orders of magnitude in the limitless vacuum of space.  Large,
kilometer-sized structures can handle amazing amounts of solar energy with
very little mass.

* microgravity manufacturing

Containerless processing and a whole host of other techniques have made
great strides, but will not come to their full fruition until they can
be built from space-based resources, and themselves process space-based
resources on scales many orders of magnitude larger than the limited
experiments launched from earth today.

If we can work with these trends, it is not inconceivable that the
"vitamins" for a teleoperated mining/manufacturing infrastucture will
mass only a few dozen Pegasus or EML launches.  In fact, I am currently
designing a system that uses solar-thermal power, gravity well maneuvers,
and aerobraking to retreive small comets into LEO.  The whole system takes
only 4 Pegasus launches to start up.  After that, each set of 4 Pegasus
launches can supply thousands of tons of refined materials (H20, LOX, LH,
LN, CH4, NH3, etc. etc.) for space industry.   Unlike lunar mining,
this provides a whole suite of chemicals at a far lower price ($10/kg
instead of $1,000/kg or more).   This uses "today's technology" in the
sense that no nanotechnology, AI advances, etc. are needed.  The biggest
limiting factor: we aren't tracking the #@!$!$#@ comets yet!  We _do_ need
advances in astronomy to make this scheme work.  I hope to see such
advances in the next 5-15 years -- a combination of the new telescopes
coming on-line, and a new emphasis on comets as space resources by the
space community.  Small asteroids (silicon, metals) could be retrieved
with a somewhat more sophisticated effort, but this effort would not
necesarily involve more launch mass.   Ice is much easier to mine than
hard dirt and rock, but we will need to also develop techniques for the
latter.  As is usual with technology, the expertise and products gained
from the smaller-scale operations will allow us to bootstrap into the
larger-scale tasks of building large-scale space industries and space
colonies at a far lower cost than that of trying to accomplish such a
gargantuan project from scratch.

Now, that is not to say that this is easy.  Intellectually, at least,
this path is much more difficult than the old chem rocket/space station/
Moon/Mars paradigm.   However, economically and politically it is far,
far cheaper.   If we follow the old failed paths, we are doomed to defeat.
By consiously working towards increasing value/lb. and letting the
solar system do the work for us, we _can_ achieve space colonization,
the "work of generations" (Goddard).





--
Nick Szabo            [e-mail]
"If you want oil, drill lots of wells" -- J. Paul Getty
The above opinions are my own and not related to those of any
organization I may be affiliated with.

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

End of SPACE Digest V13 #355
*******************