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Date: Fri, 18 Sep 92 05:07:24
From: Space Digest maintainer <digests@isu.isunet.edu>
Reply-To: Space-request@isu.isunet.edu
Subject: Space Digest V15 #216
To: Space Digest Readers
Precedence: bulk
Space Digest Fri, 18 Sep 92 Volume 15 : Issue 216
Today's Topics:
Alien substance from space
A modest proposal
Drop nuc waste into sun
Ethics
Ethics of Terra-forming
How does population relate to space?
NASA working on Apollo rerun
phone # for Mt. Lick Observatory
PLANETLIKE OBJECT SPOTTED BEYOND PLUTO (2 msgs)
Pluto Direct Propulsion Options (2 msgs)
Re- Terra-forming, The E-ca
Space Platforms (political, not physical : -)
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: 17 Sep 1992 18:12:10 GMT
From: Jeff Bytof <rabjab@golem.ucsd.edu>
Subject: Alien substance from space
Newsgroups: sci.space
Solvent outgassing and/or exotic chemical reactions with the
rarefied gasses of Earth orbit?
Debris from broken Shuttle toilets?
Jeff Bytof
rabjab@golem.ucsd.edu
------------------------------
Date: Thu, 17 Sep 1992 20:08:58 GMT
From: Thomas Clarke <clarke@acme.ucf.edu>
Subject: A modest proposal
Newsgroups: sci.space
In article <BuqEEI.CoG@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer)
writes:
> In article <ballard.28@panther.adelphi.edu> ballard@panther.adelphi.edu
(Terry Ballard) writes:
> >Considering how much moon material there is down here, why couldn't a
> >few of those rocks be ground into little bits, mounted and sold...
>
> Well, for one thing, because I believe the US is signatory to a treaty
> that prohibits this kind of thing. I don't remember the details.
Reminds me of a scheme a friend and I batted around once: Rent a GAS
CAN (Shuttle getaway special cannister), fill it with small open glass
vials. Once in orbit, expose the interior to space and seal the vials
with timed resistance heating or some such mechanism. After recovery
mount the vials tastefully on wooden plaques and sell as PERSONAL SPACE.
Since rocks were sold as PETS, we thought this was a sure winner.
I wonder if the treaty Henry cites prohibits the private possession
and commercial sale of bits of nothing returned from space ?
--
Thomas Clarke
Institute for Simulation and Training, University of Central FL
12424 Research Parkway, Suite 300, Orlando, FL 32826
(407)658-5030, FAX: (407)658-5059, clarke@acme.ucf.edu
------------------------------
Date: Thu, 17 Sep 1992 17:33:49 GMT
From: Jordin Kare <jtk@s1.gov>
Subject: Drop nuc waste into sun
Newsgroups: sci.space
In article <1992Sep16.233411.959@cs.rochester.edu> dietz@cs.rochester.edu (Paul Dietz) writes:
>In article <1992Sep16.200423.18294@s1.gov> jtk@s1.gov (Jordin Kare) writes:
>
>>The sun is the wrong destination, even though it is the most naively
>>popular, because it's extremely hard to get to from Earth; you have to
>>kill Earth's _entire_ 30 km/s orbital velocity. Alternatives include:
...
>> Ejection from the Solar System (My preference; requires
>> 16 kms delta-V in _one_ burn, no final burn, no precision
>> navigation.
>
>
>There's an easier way to get the stuff out of the solar system. Shoot
>the stuff off into solar orbit, then blow it up (I mean really blow it
>up, to vapor, via a low-yield nuclear explosion). The debris gets
>entrained in the solar wind and is swept out of the solar system at
>100 km/s. This would reduce the delta-V needed to only 4 km/s or so.
Well, actually, I was giving the delta-V to get from the Earth's surface
to the destination; getting out into solar orbit requires 11+ kms, not 4.
However, the point is well taken. Unfortunately, launching any kind of
explosive along with the payload drastically increases the risk --
how do you guarantee that it _will_ explode out in space and _won't_
explode under any conceivable circumstances on or near Earth?
There is one failure mode of the laser launch system that leaves the
payload in Solar orbit (if the laser fails between Earth escape and
Solar escape) and I did propose one possible "recovery" from that
failure as being to send an explosive out to rendezvous with the errant
payload and blow it up, as you suggest.
>
>It would be silly to dispose of most the fission products in space
>(most are too short lived), but one, I-129, is rather longlived (16
>million year halflife) and could simply be allowed to sublime and be
>swept away.
The main reason for disposing of more or less everything is that you
avoid reprocessing and associated risks of leakage, generation of
additional waste, etc. If you _do_ reprocess, of course you
separate out the short-lived stuff and let it decay on the ground
as much as you can.
>
> Paul F. Dietz
> dietz@cs.rochester.edu
>
Jordin Kare
--
Jordin Kare jtk@s1.gov 510-426-0363
------------------------------
Date: Thu, 17 Sep 92 19:48:38 EDT
From: Tom <18084TM@msu.edu>
Subject: Ethics
>>I submit that you either value life, or not. No middle ground.
>I have puzzled over this a while, and my conclusion is that it is missing
>an adjective. "your" should be in front of "life"; otherwise it is self-
>contradictory. Either there is a middle ground or not; and the last paragraph
>quoted above describes a middle ground, where some life is valued more than
>other life. This makes no sense unless "life" is replaced by "your life".
It's not contradictory. You can value some life more than other life, but
not some life more than human life, unless you are highly confused. If you
value life-in-general, you must value Human life (at least your own) as
much. Call them equal, if you like, and they are interchangable. Any
compromise depends on whatever is between life and non-life. Good luck.
>>But, if you do value life, than you must conclude that terra-forming
>>Mars would be good, as it would support more life, and, especially, Human
>>life. Or, you may decide that the terra-forming question is intractable,
>>unanswerable, nuetral. In no case would you conclude that terra-forming
>>would be bad, unless you are an anti-lifer.
>>The only way you can logically make the situation on Mars the same as on
>>Earth is to a) Demonstrate that life there affects life here, or
>>b) Assert that life-in-general has value without Human life. (This
>>choice is the route many greens take, and it is for this reason that many
>>people correctly identify them as anti-life double-thinkers. Anti-life
>>non-double-thinkers have to be dead.) You can also jump out of the system
>>and c) claim that value exists seperate from Human Choice.
>Ah. I suppose that works too; instead of "life" we could say "human life".
>Actually that's better. It makes sense that way.
Either way, the argument for terra-forming is unchanged. See below.
>Of course I disagree. I guess that in Tommy's doublespeak I am an anti-life
>double-thinker, as I think that life-in-general does just fine without Human
>life.
Of course it does just fine. Obviously this is true, since (I believe)
we evolved from other life. I was not arguing about it's ability. I was
arguing about it's value. It has no value without human life. You may
value said life. But can you show it to be more valuable than you?
Some people have died to protect life-forms. They beleived that they
were less valuable. They were right, about themselves. But not me.
If someone killed all humans to protect the Earth, I guess I'd have
to admit that we were less valuable, since we didn't cut the natural-
selection criteria. But this judgement depends on time-travel to
work. The day the Humans are gone, value doesn't exist. My argument
is not 'double-speak' as it does not depend on contradictions.
>Or, more to the point, its purpose is not to augment Human life.
I never said it's value existed if it AUGMENTED human life, I said it's
value NECESSITATED human life. If you value life-in-general, then you
must value human life AT LEAST as much. If you didn't, you would die,
making it impossible for you to value life-in-general. That is why
'value of life' can be freely interchanged with 'value of human life'
It needs us to have Value. We need it for food. That's why I freely use
'value life' where you might prefer 'value human life'. In this particular
ethical argument (as well as many others) they are interchangable.
>Although it might be fun for us to pretend otherwise, we are not God. The
>rest of life, Earth-based or Mars-based, was not put there for us to casually
>destroy just because it does not augment our convenience.
'Convenience' is a pejorative term for 'valuable'? I wouldn't call
terra-forming a planet 'convienient', but I would call it valuable.
And since when was destroying our own ecosystem 'convienient'? I'd have
to say that not breathing or eating would be damned inconvienent :-)
So why was life 'put' here? What's the purpose? I'd like to hear it. Even
better, how about a purpose that is contradicted by our terra-forming
of Mars? The best purpose I ever heard, for life, was the creation of
more life. Well, for crying out loud, that's what I'm arguing for!
Was it 'unethical' for photosynthesizers to wipe out so many life-forms?
If we are talking about absolute value, then life-in-general is bad,
since it all evolved from life-forms that did just what you are calling
unethical. Yes, our lives depending on the death of other creatures
is unfortunate. We didn't set it up that way, and the only way you
can deal with it is to kill yourself, or feel guilty all the time,
or recognize that life-in-general is still good, despite the way it works.
The first two are contradictory, so the third is the healthy choice.
BTW, we are God, unless you think He really exists. The thing God
hates, in most religions, is our understanding of value, since He is
required for 'absolute value'. God is dead, and so is absolute value.
But our arguments require absolute value! Mine is valid, though, as the
absolute value that I need is 'life is good', and I can depend upon
your existence to support it. If you maintain that all value is relative,
not only do you contradict your own existence, but you concede the
argument as a draw.
>>The only possible question about Mars-terra-forming; "Is it good for us?"
>This reminds me of a bit of history. In the 1970's the US got involved in
>some covert activities in Chile. The US Ambassador to the UN, Jeane
>Kirkepatrick, replied when asked about this, "What is good for the US is not
>necessarily good for the rest of the world."
When I said 'us' I meant 'humans', not 'governments', or any other
group that has a history of valuing death. And just because JK thought
interfering with other gov's was good for the US gov doesn't mean it was.
In my understanding, what is good for the US is good for the rest of the
world: Free trade, freedom to travel, free communication. Oh, and
terra-forming Mars :-)
>>If you think there is some other, more important question, you are an
>>anti-lifer, and, unless already dead, a hypocrite.
>I guess, then, that I am a hypocrite, because I do think there is some other,
>more important question. A question of ethics.
What question of ethics have I missed? Or did you mean a question of
value? I admit, valuing life is not necessary. It's just contradictory
to not value it, if you are alive. When actions (keeping yourself alive)
contradict thought (thinking that life is not valuable) it's hypocrisy.
>Of course when it comes down to survival, one wishes to choose one's own
>individual life and species survival over and above other individuals and
>species.
I never said anything about our species being more valuable. The value
of other life to our lives is the strength of the Green Movement. It's
weakness is the incorrect belief that we are less valuable that other life,
as we are the SOURCE of ALL value. Not the source of the things that
we value, not the source of absolute value, but the source of any value
that we can ever experience. No humans = no value, unless you are anti-life.
>But when we have developed the ability to completely wipe out
>an ecosystem (this assumes we can Terraform Mars, and Mars has some sort of
>life, two fairly tall suppositions, I admit), and choose to exercise this
>ability just because we *can*, just because it is *convenient* for us, I
>maintain it is unethical.
But, every time you sterilize a piece of lab equipment, you wipe out an
ecosystem. Ditto for taking anti-biotics, brushing your teeth, washing
the car, or keeping your lawn short ('legal' in my town. Bunch o' jerks!)
So 'wiping out an ecosystem' is not a valid reason for avoiding an
action. What about if we can preserve the hypothetical Unique Life-form?
If it's value depends only upon it's existence, we can easily capture
some, and put it in a bottle. Life-form safe, no barrier to T-forming.
Please understand, the ethical argument depends upon value, and value
depends upon human life. As long as this is true, you cannot argue for
the value of life-in-general without already assuming equal-or-better
value for human life. That's why this question of ethics must always
come down to "Is it good for humans?", or, in questions of lesser scope,
is it good for me/us/preserving value.
(Before you bring up the example of say, a killer shooting cops to protect
his freedom, keep in mind that we will be moving towards the questions
of enlightened self-interest, Kant-in-general, etc., and should be taken
to private mail, as we will lose the Mars-angle. My argument, I will
freely admit, depends upon the unique situation involving a place where
no people live, which makes the ethical question much simpler.)
The 'cultural relativism' or 'species relativism' argument makes Hitler
ethically equal to Ghandi. Your loyal dog equal to killer bees. Do you
really think this is the case?
>It doesn't necessarily follow that anti-terraformers are also anti-lifers.
True. They could just have an opinion. But, to argue against it requires
the anti-life premise, or a demonstration of why terra-forming would hurt
humans. Since terra-forming, to me, means 'making a planet humanly
habitable', that demonstration will be a toughie.
>Consider the limit, for example, where there are as many humans packed onto
>the Earth as the land will allow, packed like sardines in a can, and assume
>this state could somehow be maintained indefinitely. By your formula, you
>would be forced to say this was a better situation than the present one,
>since there would be more humans, and more is always better, and humans
>are better than other life.
I have been arguing from the fact that any value depends on human life.
This is different than the question of quality-of-(human) life. I think
you have misunderstood my argument. I never said humans are better than
other life. I said that they must be valued AT LEAST as much as other
life, since the value of other life disappears without humans, and they
are alive.
>Clearly there are more things in Heaven and Earth than are dream't of in
>your philosophy. There is a place in Peru that is the driest place on this
>planet, where the time between rains is measured in decades. You could
>"terraform" this place, make it into a lush garden, but then you would
>have destroyed a thing that exists as much in the mind as it does in
>reality.
Why terra-form something already terra-formed? It's on Earth, already
reachable by forms of life, which live there if they can.
BTW, the Unique-is-Valuble argument applies to Love Canal, psychosis,
and lots of other things that people are working very hard to eliminate.
Unless you are talking aesthetics; a whole different argument, which
still dependens upon Humans for Value.
>Anyway, the point is there are plenty of points of view that exclude
>the desirability of terraforming that do not fit into your Procrustean
>formula.
Any ARGUMENT depends upon logic, ie., formula. If you have a problem
with that, you should drop it, as you are bound to get lost, leaving you
with no option but attack, like calling said argument by pejorative names.
'Points-of-View' do not necessarily depend upon logic and reality.
When they do, they are called 'judgements'. You are entitled to your
opinion, as well as the belief that it's a judgement. But that doesn't
mean it's true.
>And if you don't think people can righteously object to
>terraforming rocks, why don't you suggest making farmland out of
>the Alps or the Himalayas?
Becasue life spreads just fine by itself. If life could live there,
it would. Not to mention the question of ownership, cost vs. benefit,
and a whole lot of other things. If the owners thought it would
be valuable to colonize life on those rocks, they probably would.
Anyone can righteously object to anything. I'm not talking about
objections, I'm talking about arguements. Dave said we could hurt Mars.
We can't, so his argument against terra-forming fails.
Look, folks, here it is, in a nutshell:
1) Life-in-general has +N value. (assumption)
2) Human (sapient) life is at least as good. (Reasons why, below)
3) We can live on Mars, if we can terraform it. (def. of terra-form)
4) Therefore, terra-forming Mars is at least as good as life-in-general.
5) IF: we can put more life on Mars than is there now,
THEN: T-forming is better than not T-forming, as the abundance
of life-in-general will increase.
Why human life *must* be at least as valuable as other life:
A) We define value (covers all things of value)
B) We are alive (covers all life-forms)
C) We kill to survive (Meat is murder: So is salad. Covers all organisms)
Anyone that concludes that 4) is false must believe one of 5 things:
a) Human life is not as good as other life, a contradiction, upon which
no valid argument can be based. b) That life-in-general is bad, also
a contradiction, since only live people can think it. c) There is no
actual value; so why does this person even care? d) There is some
source of absolute value, which only they have a line on, undemonstrable.
e) Value depends upon uniqueness, which is logically identical to c)
as all of reality is always 'unique' compared to any other time.
If it ever came down to it, I'd be nuts to think that votes always fall
for the logical goal, but the argument is valid, and, I think, unrefutable.
If you want to continue, try the aesthetics angle.
-Tommy Mac . " +
.------------------------ + * +
| Tom McWilliams; scrub , . " +
| astronomy undergrad, at * +;. . ' There is
| Michigan State University ' . " no Gosh!
| 18084tm@ibm.cl.msu.edu ' , *
| (517) 355-2178 ; + ' *
'-----------------------
------------------------------
Date: 17 Sep 92 17:28:43 GMT
From: Alex Howerton <alexho@microsoft.com>
Subject: Ethics of Terra-forming
Newsgroups: sci.space
In article <5tzn26k.tomk@netcom.com> tomk@netcom.com (Thomas H. Kunich) writes:
>What ever life there might be on Mars, or anywhere else for that matter,
>at least has the right to exist. Is man God, to destroy other life-forms
>without much measured forethought? Besides you never know the full extent
>of what you might do by changing some significant variable in any given
>environment. Or in other words -- saving some Martian bunny rabbit may
Man is not God, Man (or, for the pc sensitive, hupeople) is man, who by
her very nature must kill and eat to live. No life has the "right" to
exist, for rights are intellectual creations of mankind. Spacies have a
biological imperative to survive. and the species that can kill and eat
another species, or in some other way limit the other species competition
for resources, is the species that survives.
I am not advocating by all this that we go a trash Mars. We can
severely limit our own chances of survival on a utilitarien level by
blundering into a new environment before we fully understand it. Who
knows? a species on Mars might hold the miracle cure for AIDS. The species
most likely to survive is the most intelligent species, who acts upon and with
a full understanding of the parameters and ramifacations of its actions.
In this way we have a better chance of avoiding mass extinction, like the
dinosaurs (I wonder, if the dinosaurs would have been intelligent enough
to build an asteroid avoidance system, would they be around to tell us about
it today? Most likely not, because then mammals would not have evolved.)
End of diatribe.
------------------------------
Date: 17 Sep 92 19:54:58 GMT
From: Gary Davis <gdavis@griffin.uvm.edu>
Subject: How does population relate to space?
Newsgroups: sci.space
World population relates to the most fundamental space possible,
personal space.
--
Gary E. Davis WQ1F (On AO13)
University of Vermont Land Liner's dial 802-656-1916
References " The Joys of Rumination Without The Cud", Elsie circa 1965
------------------------------
Date: Thu, 17 Sep 1992 17:01:36 GMT
From: Henry Spencer <henry@zoo.toronto.edu>
Subject: NASA working on Apollo rerun
Newsgroups: sci.space
In article <BuozDu.FtK.1@cs.cmu.edu> amon@elegabalus.cs.qub.ac.uk writes:
>I agree with you here. LOR was selected only for political reasons. Wernher
>wanted a huge rocket (the Nova) that went direct A to B and back. That is
>understandable. WVB like to build big skyrockets. People interested in
>getting something that would be more supportable in the future wanted EOR
>(earth orbit rendezvous) and assembly. Kennedy sent the message down that
>LOR would be it because it had the best chance of beating the russians.
You might want to read "Chariots for Apollo" (the NASA History Series book,
not the other one) on the matter. While politics may well have entered
the picture, there were major technical issues pointing towards LOR as well.
In particular, the folks in Houston tried very hard to come up with a
detailed design for an EOR (or direct-ascent) lander... and failed. It
doesn't look hard until you start trying to give the crew an adequate view
of the landing area; then it looks extremely difficult. Houston came
around to favoring LOR partly because the more closely they looked at
this problem, the worse it got.
Don't overlook the fact that politics were pushing the other way, too.
At least some of von Braun's initial opposition to LOR came about because
EOR gave his people (a) more work and (b) better chance of continuing work.
After this was dealt with to his satisfaction, and some of the technical
issues were explored in more detail, he came around to favoring LOR.
I'd be very surprised to hear that Kennedy was stupid enough to try to
dictate such a technical decision, especially since his own advisors mostly
backed EOR (and indeed there was an infamous public near-fight about it
when NASA was pushing LOR, Jerome Wiesner still backed EOR, and Kennedy
asked about it on a visit to NASA).
>Commercial purchase is certainly the only way to go. I think it would be
>silly for NASA to go out and start an R&D project to build a new SV. Far
>better is to simply say "I want N tons of my cargo delivered to lunar
>surface coordinates X,Y,Z by no later than time T". Then buy the service
>from whoever wishes to supply it...
The real problem with this is going to be convincing potential suppliers
that you mean it and will keep your promises. It's rarely possible to
buy insurance against government policy changes, so that's a big risk...
especially given the US government's recent history.
--
There is nothing wrong with making | Henry Spencer @ U of Toronto Zoology
mistakes, but... make *new* ones. -D.Sim| henry@zoo.toronto.edu utzoo!henry
------------------------------
Date: 17 Sep 92 17:45:46 GMT
From: Leslie A Dent <lad30@RUTS.ccc.amdahl.com>
Subject: phone # for Mt. Lick Observatory
Newsgroups: sci.space,sci.astro
Does anyone have a phone # for Mt. Lick Observatory which is on top of
Mt. Hamilton in San Jose, CA. My husband wants to find out if he can
take a group of jr high students up there for a tour.
Thanks,
Leslie Dent
------------------------------
Date: 17 Sep 92 15:38:56 GMT
From: John McDonald <jmcd@cea.berkeley.edu>
Subject: PLANETLIKE OBJECT SPOTTED BEYOND PLUTO
Newsgroups: sci.space,sci.astro
From the San Francisco Chronicle, Wednesday 16 September 1992:
PLANETLIKE OBJECT SPOTTED BEYOND PLUTO
Astronomers have detected a small, faint object beyond
Neptune and Pluto that could be the first direct evidence
for the existence of a broad belt of icy minor planets
that is presumably the source of many comets streaking
in from the fringes of the solar system.
The new object was sighted two weeks ago by astronomers
using electronic sensors on an 88-inch visible-light
telescope operated by the University of Hawaii on Mauna
Kea. The initial observations, described yesterday,
indicate that the object is about 120 miles in diameter
and has a reddish glow, suggesting an icy surface rich
in organic material.
The observations were made by David Jewitt of the University
of Hawaii and Jane Luu of the University of California at
Berkeley.
Preliminary calculations showd that the object, designated
1992 QB-1, is travelling in a 200 year orbit ranging from at
least 37 AU to 59 AU. That would take it 3.4 billion to 5.5
billion miles from the sun.
"We think this is the first of a large number of similar
objects waiting to be discovered in the outer solar system,"
Jewitt said.
________________________________________________________________
At an AAS meeting, i had seen a talk that described a
new theory of a belt of icy comet-like or Pluto-like
objects in the outer solar system. I guess this would
be the first observation of such.....
Anyone else see any news about this?
john
center for euv astrophysics
------------------------------
Date: 17 Sep 92 19:40:32 GMT
From: Greg F Walz Chojnacki <gwc@csd4.csd.uwm.edu>
Subject: PLANETLIKE OBJECT SPOTTED BEYOND PLUTO
Newsgroups: sci.space,sci.astro
From article <44750@ucbvax.BERKELEY.EDU>, by jmcd@cea.berkeley.edu (John McDonald):
>
> From the San Francisco Chronicle, Wednesday 16 September 1992:
>
> PLANETLIKE OBJECT SPOTTED BEYOND PLUTO
>
> [deleted stuff]
> Preliminary calculations showd that the object, designated
> 1992 QB-1, is travelling in a 200 year orbit ranging from at
> least 37 AU to 59 AU. That would take it 3.4 billion to 5.5
> billion miles from the sun.
>
> "We think this is the first of a large number of similar
> objects waiting to be discovered in the outer solar system,"
> Jewitt said.
>
> At an AAS meeting, i had seen a talk that described a
> new theory of a belt of icy comet-like or Pluto-like
> objects in the outer solar system. I guess this would
> be the first observation of such.....
>
> Anyone else see any news about this?
>
This was reported in IAU circular 5611. Marsden computed possible orbits,
one of which was as described above. The belt, called the Kuiper belt,
was posited originally by the great planetary astronomer Gerard Kuiper,
I think the '50s.
I gather the arc of observations was rather small, however, and Marsden took
pains to not the the above orbit is only one of a few possible solutions
(which also include a circular retrograde orbit only 15 AU out). More
observations are planned for the next dark observing period at the end
of this month, so we may geta better idea then. Marsden did add, though,
that for a really good orbit, the object will have to be observed through
the end of the year.
I'm viewing it cautiously, but it's pretty interesting if true!
Greg
------------------------------
Date: 17 Sep 92 18:53:42 GMT
From: Dave Tholen <tholen@galileo.ifa.hawaii.edu>
Subject: Pluto Direct Propulsion Options
Newsgroups: sci.space
Nick Szabo writes:
> Let's get the planetary exploration
> community together to bring about these improvements instead of every
> project sitting around waiting for the other guy to do it.
If what you need is transportation and you have a limited budget, say
one or two thousand dollars, what are you going to do? Probably go to the
used car lot to buy something that will get the job done rather than trying
to convince the money providers that you need a new car with some new
technology. And can you afford to wait for Detroit to incorporate this
new technology and deliver it to you by the deadline?
The problem is that the Pluto mission budget is extremely tight. Goldin
wants another 20 kg trimmed from the spacecraft mass, and we thought the
Pluto spacecraft was already a real lightweight (compare with the Clementine
spacecraft, which has been described as a lightweight spacecraft, and
Clementine is more than twice the mass!). There's no room in the Pluto mission
projected budget to develop ion drive technology. If we said we required
it (which we don't, even though it would be nice), it would probably kill
the project. In other words, if you stick your neck out, and there's good
chance it'll get chopped off, are you going to stick your neck out? Not
very likely. Mind you, nobody I've encountered is against the technology.
The problem is what has been called the "Christmas tree" effect. Take a
basic mission, and argue that we can make it that much better by adding
this and that, and pretty soon you've got a bloated mission that costs
more than originally proposed and funded at. We lost half of CRAF/Cassini
this way. There's no question we can do a Pluto mission better with ion
drive. The question is, can we do a Pluto mission that is good enough
without it? We believe the answer is yes. If you start adding onto good
enough to make it better, you're running the risk of having your neck
chopped off.
What we need to do is separate the technology development from any one
specific project. NASA Code X (Advanced Technology) may be the answer,
but there's lots of advanced technology development projects that are
waiting for funding. Ion drive isn't alone.
------------------------------
Date: Thu, 17 Sep 1992 18:26:46 GMT
From: David Knapp <knapp@spot.Colorado.EDU>
Subject: Pluto Direct Propulsion Options
Newsgroups: sci.space,sci.astro,alt.sci.planetary
In article <1992Sep17.013658.5917@news.Hawaii.Edu> tholen@galileo.ifa.hawaii.edu (Dave Tholen) writes:
>> Wonder if there would be "snow" storms when Pluto's atmosphere freezes out,
>> or would just form frozen "dew" on the surface. Maybe both, as the gas
>> with the higher freezing point "snows" out before the gases with lower
>> freezing points condense out. (Do I remember correctly that there are
>> more than one gas in Pluto's atmosphere?)
>
>"Storm" is a relative term. Pluto's atmosphere is so thin that you'd never
>get anything like what we have on Earth. On the other hand, Voyager showed
>streaks on Triton, apparently driven by winds, even though Triton's
>atmosphere is about as thin as Pluto's. Whether Pluto also has winds is an
>excellent question. If the surface is isothermal, which could be the case
>if methane frost is everywhere, then there isn't much of a mechanism to
>drive winds, but if the darker regions are exposed rock, for example, then
>temperature differences could exist, thereby driving some weather on Pluto,
>so you might have something more than just the equivalent of dew forming.
What is your criteria for 'isothermal'? Wouldn't we expect *some* temperature
differentials from solar heating even though albedos may not be extremely
low?
>Yes, there are several gases in Pluto's atmosphere. Methane, nitrogen, and
>carbon dioxide have all been detected spectroscopically (the latter two
>only very recently). The vapor pressure of nitrogen is highest, followed
>by carbon dioxide, so nitrogen is probably the dominant gas.
--
David Knapp University of Colorado, Boulder
Perpetual Student knapp@spot.colorado.edu
------------------------------
Date: 17 Sep 92 17:35:23 GMT
From: Alex Howerton <alexho@microsoft.com>
Subject: Re- Terra-forming, The E-ca
Newsgroups: sci.space
In article <g1znvxp.tomk@netcom.com> tomk@netcom.com (Thomas H. Kunich) writes:
>In article <BuMqG9.MzE.1@cs.cmu.edu> steve_abrams@executive.isunet.edu (Steve Abrams) writes:
>>
>>However, if D-He3 fusion comes to pass, you go straight from nuclear energy to
>>electricity.
>
>I prefer real science over Ex Deus Machina. If and when fusion becomes a reality
>we can discuss it's ramifications on society.
I bet you thought Arthur Clarke was wasting his time writing about
communications satellites and geosynchronous orbit.
Alex Howerton
alexho@microsoft.com
------------------------------
Date: Thu, 17 Sep 1992 16:57:55 GMT
From: Frank Crary <fcrary@ucsu.Colorado.EDU>
Subject: Space Platforms (political, not physical : -)
Newsgroups: sci.space,talk.politics.space,alt.politics.marrou,alt.politics.libertarian
In article <STEINLY.92Sep16135652@topaz.ucsc.edu> steinly@topaz.ucsc.edu (Steinn Sigurdsson) writes:
> Does that mean no more intenational agreements to keep certain
> frequencies clear for radio astronomy?
>Does it mean Cuba can finally turn on its big transmitter and start
>enlightening the population of Florida (+47 nearest states or so)
>as to the true benefits of socialism? ;-)
>Or does it mean I can go out and bomb the local country stations
>to clear the air for the low power alternative rock stations?
>Maybe Hughes should start development work on "bumper" satellites,
>might be some neat ways to clear out valuable orbital slots needed
>soon...
I doubt it: The Libertarians generally make clear exceptions, for
occasions where one person harms another. In all of the above cases,
I suspect they would insist on no preventative regulation before hand,
but arrest or support civil suits against anyone doing that sort of
thing, _after_ they had done it.
Frank Crary
CU Boulder
------------------------------
End of Space Digest Volume 15 : Issue 216
------------------------------