Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT_ZIP/spacedig/V16_0/V16NO013.ZIP/V16NO013

Internet Message Format | 1993-07-13 | 29KB

Date: Thu,  7 Jan 93 05:06:39
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #013
To: Space Digest Readers
Precedence: bulk


Space Digest                Thu,  7 Jan 93       Volume 16 : Issue 013

Today's Topics:
                  *** BUSSARD RAMSCOOP *** (2 msgs)
                    CFV: sci.geo.eosdis moderated
                             DC-Y funding
                          DC cost estimates
                     DC vs. Shuttle capabilities
             Genetically Engineered Microbes in Real Use?
 Government-run programs Was: Re: Justification for the Space Program
                     Moon Dust For Sale (2 msgs)
                         question about SETI
                       Railgun in Southwest US
                         russian solar sail?+
                                 SEI
     Who can launch antisats? (was Re: DoD launcher use) (2 msgs)

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

Date: Wed, 6 Jan 1993 21:29:24 GMT
From: Henry Spencer <[e-mail]>
Subject: *** BUSSARD RAMSCOOP ***
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (fred j mccall 575-3539) writes:
>I didn't get the impression that that was what he meant.  After all,
>if you have antimatter to use in heating the bulk of your exhaust
>products, why do you need fusion? ...

There have been serious proposals, actually, to use antiprotons to do
the heat-and-compress trick for fusion.  The machinery needed for this
is (probably) a whole lot lighter than for laser-ignited fusion, making
it much more practical for rocketry.

However, (a) proton-proton fusion is well beyond what this technique can
easily achieve, and (b) Fred is correct, that wasn't what I was talking
about.

>yuou couldn't cruise forever, but I wouldn't think it would require
>amounts of anti-matter that would seem ridiculously large, given the
>scale of such a vehicle.

Kilogram quantities of antimatter are quite adequate for early interstellar
probes, given modest vehicles.  I don't have numbers for the antimatter-
fuelled ramjet on hand, but it *has* been studied and it looks plausible.
--
"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
       -Gene Cernan, the Moon, Dec 1972 |  [e-mail]  utzoo!henry

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

Date: 6 Jan 93 23:29:35 GMT
From: Henry Spencer <[e-mail]>
Subject: *** BUSSARD RAMSCOOP ***
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Jason Cooper) writes:
>However, it still seems to me that carbon-catalyzed may be a great way to
>go.  1) your carbon keeps coming back ...

I think if you look into it, you'll find that *you can't get adequate
burn rates* just by throwing in some carbon.  It simply isn't that easy,
not unless you assume truly fantastic chamber conditions.

Bear in mind, too, that you're likely to lose a good bit of carbon out
the tailpipe... especially if you're trying to build a scramjet.

>2) you won't have to carry
>around what I see as becoming GIGANTIC amounts of antimatter...

The amounts of antimatter get huge only when you start trying to achieve
seriously relativistic velocities.
--
"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
       -Gene Cernan, the Moon, Dec 1972 |  [e-mail]  utzoo!henry

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

Date: 6 Jan 93 14:34:46 GMT
From: Cindy Posinski <[e-mail]>
Subject: CFV: sci.geo.eosdis moderated
Newsgroups: news.announce.newgroups,news.groups,sci.space,sci.astro,sci.geo.fluids,sci.geo.geology,sci.geo.meteorology

      CALL FOR VOTES FOR THE CREATION OF THE SCI.GEO.EOSDIS NEWSGROUP

The sci.geo.eosdis newgroup will be used by the Earth Observing System Data
and Information System (EOSDIS) community for the sharing of EOSDIS related
information.  It will include postings of "The Processor" and the "The Earth
Observer," newsletters containing timely EOS news events and information on
up-coming meetings.  The newsgroup will also contain information regarding the
availability of new data sets, and other important EOS related material.
There are currently hundreds of researchers and scientists around the world
involved with EOS, and this would be a great forum for the sharing of ideas.

The sci.geo.eosdis newsgroup will be moderated by an EOS Project Office
representative.

TO VOTE:  If you would like to see sci.geo.eosdis created, please send your YES
          vote to:  [e-mail].

      If you do not want the sci.geo.eosdis created, send your NO vote to:
          [e-mail].

Please make sure your vote is clearly worded, such as "I vote YES for the
creation of the sci.geo.eosdis newsgroup." or "I vote NO for the creation of
the sci.geo.eosdis newsgroup."

Voting will be open until 27 Jan 93, 23:59 UTC.

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

Date: 7 Jan 93 02:48:15 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: DC-Y funding
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (John Roberts) writes:

>The Shuttle only launches about eight times a year, and represents relatively
>few subsidized GAS cans, mid-deck experiments, etc. Is the market really
>*that* small?

In testimony before the House Space Subcommittee, Dennis Dunbar, VP of
the Space Systems Division at GD said that if Government bought launch
services in a commercial and competative manner then costs would be
roughly cut in half.

Yes the market is that small and government policies and systems (like
Shuttle) are sending prices up and not down.

>(And if these incidental payloads were not subsidized, the market
>might be even smaller.)

Not so. If NASA implements the voucher system authorized in last years
authorization bill they could launch more payloads for less cost. There
is a difference between providing subsidies for a hugely expensive system
like Shuttle and giving somebody enough money to launch their own payload.
The latter encourages greater reliance on lower cost systems.


  Allen

--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  [e-mail]     |  nothing undone"                                       |
+----------------------108 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: Wed, 6 Jan 1993 19:55:02 GMT
From: fred j mccall 575-3539 <[e-mail]>
Subject: DC cost estimates
Newsgroups: sci.space

In <[e-mail]> [e-mail] (Allen W. Sherzer) writes:

>In article <[e-mail]> [e-mail] (John Roberts) writes:

>>Allen generally takes projected "worst-case" cost estimates for DC
>>and multiplies them by two or more in making his calculations, which
>>I think shows he is aware of the problem.

>Actually, I doubled the estimates I have seen. They are more likely to
>be the reasonable estimates and not 'worst-case' estimates.


>>I should make one additional point regarding Allen's calculations - they
>>don't include the large opportunity cost if the Shuttle program should
>>be cancelled before DC is fully operational

>I con't follow this. It seems to me that if Shuttle is cancled it could
>more than double the market for DC flights. This could roughly cut DC
>costs in half.

Opportunity costs have little to do with the costs of DC in the
scenario given, Allen.  Opportunity cost is an economics term used to
describe the things given up because a choice is made.  The large

opportunity cost being described is NOT being able to do certain
things for a number of years if we scrap the Shuttle before DC is
ready to replace it.

As an example, one of the 'opportunity costs' of scrapping our prior
capability before the Shuttle was ready was the loss of Skylab
(because we had made a choice that left us with no ability to reboost
it).

--
"Insisting on perfect safety is for people who don't have the balls to live
 in the real world."   -- Mary Shafer, NASA Ames Dryden
------------------------------------------------------------------------------
[e-mail] - I don't speak for others and they don't speak for me.

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

Date: Wed, 6 Jan 1993 20:22:05 GMT
From: Edmund Hack <arabia!hack>
Subject: DC vs. Shuttle capabilities
Newsgroups: sci.space

Geez Phil, you make it sound like I _oppose_ the DC-X program, when I am
actively supporting it.  My basic opinion is that there are some risks
involved that need proper assessment and management.  The taxpayers
should be informed as to the risks (and the rewards) and not just
presented with rosy promises.

In article <[e-mail]>
     [e-mail] ("Phil G. Fraering") writes:
>\2. There is limited experience with composite airframes in routine
>/operational use.

>Actually, you forgot the F-22/F-23 program as well. And the F-20.

Please note the qualifiers aboove - "limited" and "routine".  None of
those are operational.  I did forget the F-117, which has a significant
composite %, but it is unclear if any load bearing members are
composite.

>I would also note that the kitplane market bit seems to indicate
>that composites are *better* understood than you think, and aren't
>being used more widely because of stodgy industry. It sounds like
>they're more innovative than Boeing/MacDac et al. Perhaps they are.

Actually, the kiplane market uses (mainly) the epoxy/fiberglass types of
composites for wings, etc.  The major objections to composites (as I
have been told) is the increased cost compared to Al and Steel.  There
are also problems with assembly and repair of composite structures that
increase costs.  The major programs that use composite structural
members that I am familiar with are the fleet ballistic missiles such as
Trident.  The aircraft industry is well aware of the potential of
composites and will use them if they are cost effective.

>After all, who flew around the world unrefuelled first?
>
>THANKFULLY _someone_ had the presence of mind to get Scaled Composites
>involved on DC-X...
>

>\3. The throttled RL-10 with nozzle extender is a new and essentially
>/untried engine. Engine development is more art than science and has a
>\history of being subject to delays.
>
>I don't think so. There were no changes in any of the "wet" parts of
>the engine, just the uncooled part of the nozzle.

From what AvLeak reported, the throttling mechanism is not a trivial
change to the engine and has had (thanks to an old Air Force contract)
only a limited test series.  The AF tests are what made the engines possible
for this program.  (That and some innovative financial deals - i.e. DC-X
is leasing, not buying the engines.)

>The stupid part
>of the nozzle, as it were. If we can't do that, we should stay on
>the ground.

I would hardly call a deploying nozzle extender trivial either.  It
should be as simple as landing gear deployment, but it is a set of
moving parts that need to work, will need inspection, repair, etc.
>
>\4. The servicing goals and rapid turnaround requirements of the vehicle
>/are doable on paper, but have been held out as very risky by an
>\independent study.
>
>An independent study which apparently had an axe to grind of its own,
>if you're talking about the TAC study.

Yes, this was the TAC study, which seemed to be unbiased.  I read a two
page executive summary that was done of it, so maybe the complete report
was not unbiased.  The conclusion of the report was that the SSX program
could probably be done with some risk.
>
>\5. The weight margins on the vehicle are very tight, a historical source
>/of problems in spacecraft and aircraft design.
>
>Hmmph. Maybe you should repeat this a couple more times for the people
>who started this, you'll help them make everyone else think it's true.

This has been a problem even for the "success oriented" Apollo program.
Great work had to be done to get the LM down to reasonable weight.  (I
may be wrong, but I recall that Apollo had two LM contractors and one
was eliminated due to design and weight problems.  Henry or others
probably remember.)  Other aircraft have had this problem - my employer,
Lockheed, had to take a $700 million writeoff on the P-3 Orion replacement
program when it was cancelled, in part, due to weight growth.  In a systems
engineering class I attended, a "model" systems engineering organization
for spacecraft and aircraft design (DOD model procurement) showed a
position for a person to keep track of weight and balances.

>
>\Even given all that, the DC-X, DC-Y, DC-1 progression is a valid and
>/prudent way to develop this class of vehicle.  There is one other source
>\of risk that is hard to quantify at this point: MacDac is an ailing
>/company, in substantial risk of major cutbacks.  Given that the company
>\is throwing a lot of IR&D money into the project, it could founder on
>/the rocks of a major financial crisis in the company.  I also give
>\MacDac high marks for the management approach, which I have heard the
>/project manager give a talk on.  It is modeled on the Lockheed "Skunk
>\Works" approach.
>
>I think people were saying the same thing about Apple at about the time
>they were developing the Mac. Everyone was talking about how they were
>going to lose out to IBM. But who's in financial trouble now?

The PC division of IBM is doing quite well - the trade press indicates
that they have 2 major problems - the parent organization is in
financial straits and they can't build enough product to meet demand.
Apple was not particularly unstable financially when the Mac was in R&D
(although the Apple III and the Lisa would have killed anyone else in
the business).  MacDac has had to be bailed out by DOD at least once in
the last two years and the C-17 project is in mega trouble, SSF may be
in trouble again this year, etc.
>
>Also, "we better not give them the project, they're a troubled
>company" is the sort of self-fufilling prophecy that's kept many
>many many good alternatives from being tried.

Be that as it may, it is still a risk.  I didn't say that they shouldn't
get the work, just that the financial condition of the company could
threaten the project, espcially since they are using IR&D funds.
>
>\Hopefully, the incoming administration will see the value of the
>/vehicle, there will be a safe and successful flight test this summer and
>\it will proceed with the DC-Y.  I consider the DC development program a
>/prudent use of the government's risk capital.  However, we need to keep
>\an eye on alternatives in case the DC program stubs its toe.
>
>You say that as if DC isn't one of the alternatives instead of one of
>the 200-million-a-year-on-design CAD queens.

I meant that there ought to be some fallback from DC-X, as it seems to
be the only existing booster development program for medium payloads.
DC-Y, et.al. are certainly viable vehicles if the program goes well.

--
Edmund Hack - Lockheed Engineering & Sciences Co. - Houston, TX
[e-mail] - I speak only for myself, unless blah, blah..
"You know, I think we're all Bozos on this bus."
"Detail Dress Circuits" "Belt: Above A, Below B" "Close B ClothesMode"

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

Date: Wed, 6 Jan 1993 21:59:30 GMT
From: Edmund Hack <arabia!hack>
Subject: Genetically Engineered Microbes in Real Use?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>I recall hearing on Chicken Noodle News that a bacterium (*Chlostridium*
>I suspect, they'll eat virtually anything, including those buried polystyrene
>bottles which were supposed to last ten thousand years and instead lasted
>five or so...) has been developed to help in some types of oil spills and
>was successfully used in a spill near Galveston a few years ago. Anyone
>know more about this?

Yes, a specially tailored microbe was used to "bioremediate" a small oil
spill in Galveston Bay a year or two ago.  It worked quite well.  In
fact, if the EPA and other groups had allowed it to be used earlier the
entire slick would have been eaten up while still in the bay.  It was
sprayed on a section of the slick that hit some wetlands.

The state of Texas has a stock of the bugs available at all times for
use on spills of reasonable size.  I have heard that if the cleanup of
the Exxon Valdez had not been such a political fiasco, they could have
used the microbes on it and significantly reduced the damage done.
There is substantial opposition to use of such microbes by certain
eco-idiot factions which has slowed their acceptance.  Such antics don't
go over well here in Texas, and they were unable to stop their use.


--
Edmund Hack - Lockheed Engineering & Sciences Co. - Houston, TX
[e-mail] - I speak only for myself, unless blah, blah..
"You know, I think we're all Bozos on this bus."
"Detail Dress Circuits" "Belt: Above A, Below B" "Close B ClothesMode"

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

Date: Wed, 6 Jan 1993 21:34:30 GMT
From: "Edward V. Wright" <[e-mail]>
Subject: Government-run programs Was: Re: Justification for the Space Program
Newsgroups: sci.space,talk.politics.space

In <[e-mail]> [e-mail] (Gary Coffman) writes:

>After the first Apollo landing, TV ratings for space coverage dropped
>sharply. The media took their cue from that. It's only climbed into
>the top 50 *once* after that, that was the launch after Challenger.

And Star Trek was always at the bottom of the ratings...

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

Date: Wed, 6 Jan 1993 17:20:12 GMT
From: Willie Smith <[e-mail]>
Subject: Moon Dust For Sale
Newsgroups: sci.space,sci.astro,alt.sci.planetary

In article <[e-mail]> [e-mail] writes:
>NASA is part of the Executive Branch of the U.S. Government.  As such,
>it receives its funding from the U.S. Congress.  Under the U.S. Code,
>NASA can't engage in this kind of fund-raising efforts, nor can it sell
>advertising on rockets, hold bake sales, or even accept volunteer labor
>from corporations

Then how come they were able to ask for 'donations' for Nasa Tech
Briefs for a while?  I sent them a few bucks once or twice, but they
stopped asking, FWIW.

--
Willie Smith     [e-mail]     [e-mail]
"That's the wonderful thing about crayons, they can take
you to more places than a starship."  Guinan - STNG

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

Date: Thu, 7 Jan 1993 01:47:14 GMT
From: Robert Frederking <[e-mail]>
Subject: Moon Dust For Sale
Newsgroups: sci.space,sci.astro,alt.sci.planetary

>Congress.  That would subvert the Constitutional power of Congress to
>fund the Federal Government.  (This kind of subversion is at the heart
>of the Iran/Contra scandal, where the Executive Branch supposedly sold
>arms to Iran, then used the money to fund the Contras without going
>through Congress.)

Since several people have been convicted of participating in this
scheme, I'd like to remind everyone that it isn't ``supposedly''.
They really did this.  The only point still under dispute is whether
Reagan somehow managed to be unaware that this was illegal.  (Sorry.)

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

Date: Wed, 6 Jan 1993 23:50:46 GMT
From: Tim Roberts <[e-mail]>
Subject: question about SETI
Newsgroups: sci.space

OK, I'm a rank amateur, I don't normally read this group, so please be gentle
with me.....

Lots of money (I understand) is being spent on SETI, on the usual quite
reasonable assumption that there may be millions of civilisations out there.
Now, it seems to me that it would be astonishing if another civilisation were
at exactly our point in technology.  Those that are far below would not be
able to send or receive anyway.  So we only need consider those that are in
advance of us, perhaps to almost unimaginable amounts.  Further, we need only
consider those that want to contact a backward civilisation like ours - if
they don't want to, they'll make sure we never know about them.

So, we are left with a civilisation that is probably very far ahead of ours,
but wants to contact us (for some reason).  Now, how would they go about it ?
Surely they'd set beacons somewhere in space that could not possibly be
missed.  And, remember, their technology is probably millenia (at least) ahead
of ours.

So, my question is, given that we ought to look for beacons that cannot be
missed:  has anyone examined the immediate vicinity of pulsars ?  I mean,
REALLY examined them ?

Wouldn't this be better than searching more-or-less random points in space ?

Tim

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

Date: 6 Jan 93 21:47:31 GMT
From: James Thomas Green <[e-mail]>
Subject: Railgun in Southwest US
Newsgroups: sci.space

I've heard a rumor that some organization (SSI?) has actually
built a large railgun somewhere in the SW USA.  It's apparently
supposed to be big enough to put small payloads (>5 kg) into
orbit, though I don't know if they've done that yet.

Is this a rumor or is there some truth to it?

/~~~(-: James T. Green :-)~~~~(-: [e-mail] :-)~~~\
| Perhaps the universe is filled by planets peopled by folks    |
| with advanced brains.  On the other hand, perhaps humans have |
| got the universe's most advanced intellects.  Either way it's |
| a mighty sobering thought.                                    |

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

Date: Wed, 6 Jan 1993 22:49:32 GMT
From: Henry Spencer <[e-mail]>
Subject: russian solar sail?+
Newsgroups: sci.space

In article <ida.726295295@atomic> ida@atomic (David Goldschmidt) writes:
>... It was a square design, which surprised me; the
>heliogyro design, developed by R. H. Macneal ... has several advantages,
>including stability (its spinning), and ease of deployment...

The stability produced by that spin is actively undesirable if you have
a maneuverability requirement.  A sail designed to be deployed in Earth
orbit, in particular, has to do 90-degree turns twice per orbit (to get
full advantage of sunlight in the "downwind" half of the orbit and
minimize losses during the "upwind" half).  JPL got away with it because
their design was launched to escape by conventional propulsion.

The heliogyro is also a very flexible structure for its sail area, with
extra dynamics problems arising from those long thin blades.  (This is
also another area where the spin hurts, because the blades see constantly
changing Sun angles to complicate their dynamics.)

Mind you, there is a whole lot to be said for easy deployment.  Deployment
is a big problem for solar sails.
--
"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
       -Gene Cernan, the Moon, Dec 1972 |  [e-mail]  utzoo!henry

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

Date: Wed, 6 Jan 1993 22:47:07 GMT
From: "Edward V. Wright" <[e-mail]>
Subject: SEI
Newsgroups: sci.space

In <[e-mail]> [e-mail] (John Roberts) writes:

>That's because SEI didn't sell, largely because of the projected
>horrendous cost (~$400 billion, if I recall correctly).

I don't think the cost was a major factor.  Lawrence Livermore's
$10-billion program didn't sell, either.  Besides, politicians
*like* spending money like drunken sailors. :-)

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

Date: Wed, 06 Jan 93 21:24:30 GMT
From: Doug Mohney <[e-mail]>
Subject: Who can launch antisats? (was Re: DoD launcher use)
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Edward V. Wright) writes:

While extracting your references to nuclear weapons makes your replies look
reasonable, extracting said references changes the tone and context of
my comments and your response...

>In <[e-mail]> [e-mail] (Doug Mohney) writes:
>
>>    A) Raised the level of tension
>
>Attacking a US carrier battle group is going to raise tensions
>a bit anyway, don't you think?

Use of one or more nuclear weapons is going to invite an escalation which the
attacking force will not wish to solicit, due to the stigma attached to them.
>
>>    B) Invited attack on any space assets you've got
>
>So, how many nations have more space assets to lose (and
>less ability to quickly replace them) than the United States?

It is likely we have a quick-launch replacement capability, either through
air breathing mysterious aircraft or (more likely) derivative ballistic missile
capability, on land and at sea.

It is unlikely the attacking third-world country would have an equalivent
replacement capability for whatever assets it has.

>
>>    C) Tossed public opinion and the world community off your side;
>>       NOT a good thing.
>
>That didn't stop Saddam Hussein from invading Kuwait.

Sure it didn't. However, the UN voted to remove Iraqi troops by the use of
force and thereby did so accordingly. Had Iraqi troops seized anything less
than Kuwait City, or removed themselves from Kuwait City without committing
anything more than token atrocities, Iraq would not be divided into three parts
today.

It is, by the way, still in three parts, mostly due to the world community
still being pissed off at Iraq's belligerant attitude.

> A lot of
>wars might be prevented if Americans came to realize that most
>of the world doesn't care a fig about "public opinion and the
>world community."

Ah. But for anything less than a full-scale nuclear exchange (which translates
to 99.987% of the possible conflicts which will occur in the next 20 years),
public opinion and what individual nations think DOES count.


                    I have talked to Ehud, and lived.
  -- >                  [e-mail]                        < --

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

Date: 7 Jan 93 00:16:23 GMT
From: Josh 'K' Hopkins <[e-mail]>
Subject: Who can launch antisats? (was Re: DoD launcher use)
Newsgroups: sci.space

[e-mail] (Doug Mohney) writes:

>>>    B) Invited attack on any space assets you've got
>>
>>So, how many nations have more space assets to lose (and
>>less ability to quickly replace them) than the United States?

>It is likely we have a quick-launch replacement capability, either through
>air breathing mysterious aircraft or (more likely) derivative ballistic missile
>capability, on land and at sea.

Could you please cite a shread of evidence that such a system is operational?
Stipulating for a moment that the capability exists, please explain how many
ground based backups there are for KH-12s or how long it takes to replace them.
Quick launch capability is after all quite useless without something to launch.


>It is unlikely the attacking third-world country would have an equalivent
>replacement capability for whatever assets it has.

If you're assuming the attacker is a third world country than you seem to be
ignoring the possibility that it doesn't have significant assests worth worrying
about.  That doesn't mean that they wouldn't love knocking ours out.

>>
>>>    C) Tossed public opinion and the world community off your side;
>>>       NOT a good thing.
>>
>>That didn't stop Saddam Hussein from invading Kuwait.

>Sure it didn't. However, the UN voted to remove Iraqi troops by the use of
>force and thereby did so accordingly. Had Iraqi troops seized anything less
>than Kuwait City, or removed themselves from Kuwait City without committing
>anything more than token atrocities, Iraq would not be divided into three parts
>today.

And the threat of that didn't stop Saddam Hussein from invading either.  Keep
in mind that attackers frequently think along different lines than their
enemies expect them to.
--
Josh Hopkins                                          [e-mail]

Q:  How do you tell a novice from an expert.
A:  A novice hesitates before doing something stupid.

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

End of Space Digest Volume 16 : Issue 013
------------------------------