Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V08/V8_249.TXT

Internet Message Format | 1991-07-08 | 18KB

From ota Fri Jun 10 03:07:45 1988
Received: by angband.s1.gov id AA12971; Fri, 10 Jun 88 03:07:29 PDT
    id AA12971; Fri, 10 Jun 88 03:07:29 PDT
Date: Fri, 10 Jun 88 03:07:29 PDT
From: Ted Anderson <ota>
Message-Id: <[e-mail]>
To: [e-mail]
Reply-To: [e-mail]
Subject: SPACE Digest V8 #249

SPACE Digest                                      Volume 8 : Issue 249

Today's Topics:
      Re: Non-sexist language (was:Space Station Names)
           Re: "What if" on Shuttle External Tanks
     Re: Vocabulary lesson #7: Expendable launch vehicles
    Re Soviet Shuttle launch soon (May 18th) - not likely
             More on anti-matter
         Re: Antimatter propulsion questions
                   Re: Mars
            Re: Naming the space station.
           Re: "What if" on Shuttle External Tanks
            Re: Naming the space station.
           Vocabulary lesson #9:  Spinoffs
----------------------------------------------------------------------

Date: 16 May 88 15:26:03 GMT
From: nuchat![e-mail]  (Steve Nuchia)
Subject: Re: Non-sexist language (was:Space Station Names)

>From article <[e-mail]>, by [e-mail] (Jonathan McDowell):
> sounds more natural.  'Crewed' is no good (see comment about
> passenger-only above), likewise 'staffed' (yuck) which doesnt have the
> right sense.  Any constructive suggestions?

"manned" is the English word with the desired meaning.

Can we worry about something important now?
--
Steve Nuchia        | [...] but the machine would probably be allowed no mercy.
uunet!nuchat!steve  | In other words then, if a machine is expected to be
[phone]        | infallible, it cannot be intelligent.  - Alan Turing, 1947

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

Date: 16 May 88 10:59:45 GMT
From: mcvax!ukc!its63b![e-mail]  (ERCF08 Bob Gray)
Subject: Re: "What if" on Shuttle External Tanks

In article <[e-mail]> [e-mail] (Jay C. Smith) writes:
>I've forgotten... why didn't the Soviets salvage Skylab?  I would think
>that concern over discovering technological "secrets" from an old
>space station would have been overridden by safety concerns for those
>under the falling debris.

Because the propaganda of having a US spacestation fall
out of the sky was worth more than the large effort to
salvage it.

And they had spacestations of their own at advanced stages
of development.
    Bob.

 than a stowed space suit. Any type of
"miniatre space ships" would also be much more clumsy. They would have to
have some kind of thruster system like the MMU..This means one more thing that
can go wrong.

-------------------------------------------------------------------------------
 Joe Walker                          |        The dream is still alive!!
 U.S. Mail:                          |-----------------------------------------
   Dartmouth College                 |    "Why don't you fix your little
   H.B. 219, Hanover N.H. 03755      |     problems and light this candle!!"
 E-Mail:                             |
   BITNET:[e-mail]  |                   - Alan Shepard
   UNIX:[e-mail] |
-------------------------------------------------------------------------------
               !{harvard,linus,inhp4}!dartvax!eleazar!seldon
-------------------------------------------------------------------------------

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

Date: 15 May 88 00:30:50 GMT
From: mnetor!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Vocabulary lesson #7: Expendable launch vehicles

> ... can be gotten rid of when they become politically
> inconvenient - or heaven forbit!  Inexpensive.

Since there is no chance of the latter while the US government is running
the show, it need not be mentioned.  Despite some of the nonsense one
hears from the more rabid anti-shuttle factions, current US expendables
are just as expensive as the shuttle.

Actually, my definition would be something like:  "a class of space launchers
which clearly are not considered expendable, based on the vast manpower and
expense devoted to every single launch".  (Case in point.  Delta is derived
from the Thor IRBM.  Thor specs said launch in 15 minutes with crew of 9.
NASA Delta launches required three months with a crew of 2000.  Yes, the
Delta is more complicated, and the payloads need more attention... but
three orders of magnitude?!?)  We will not have cheap space transportation
until we can treat space-launch failures like airliner crashes:  lamentable,
to be avoided, worthy of careful investigation... but not usually cause for
grounding the vehicle or grossly compromising its economics.  And "grossly
compromised" is certainly the word for the economics today...
--
NASA is to spaceflight as            |  Henry Spencer @ U of Toronto Zoology
the Post Office is to mail.          | {ihnp4,decvax,uunet!mnetor}!utzoo!henry

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

Date: Wed, 18 May 88 10:44:32 EDT
From: Glenn Chapman <[e-mail]>
Subject: Re Soviet Shuttle launch soon (May 18th) - not likely

In Space Digest v8, 224 Bruce Watson posts:

> Just heard that the Soviet Space Shuttle is set for launch on May 18.
> Dignitaries are assembling at the Baikonur Cosmodrome for the event.

     I am rather doubtful of any Soviet Shuttle launch in the next few days
(from today's May 17th).  The Soviets have just started to take the foreign
correspondents on the tour of the launch sites at Baikonur and the astronaut
training areas of Star city.  Also for the past week there has been only a
small piece about their space program on the Radio Moscow news.  For those
who listen to shortwave the Russians follow a standard pattern with space news.
If some big event is coming up they move relatively small articles ("the
cosmonauts have now been in orbit for X days ... ") from their normal position,
as the last item or two of their ten minute long hourly news, to one of the top
four.  Also the number of such stories increase, which is just starting to be
true.  Finally since the news tours indicate that they are keeping to their
word about publicizing the launch, they would have announced the take off well
before now if it was going to occur soon.  Heck they gave the date of the first
Energiya launch about two days before it happened.  Thus I would be rather
surprised by a Soviet Shuttle launch tomorrow or in the next few days.  It
is probable, however, that they may try to launch it before the party congress
this June (to show their country's technological advances).
     Also note that there has been strong statements from the head of the
cosmonaut corps that the first few shuttle launches will not be manned.  There
have been over 50 atmospheric test flights to date (all manned).  This
contradicts other statements that I have seen from Non-Soviet sources about the
launch version being manned.  That shows again that in this business take all
rumors with a grain of salt.  Never the less it appears their shuttle may
begin flying before this country's one lifts off once more unless we really get
a move on.

                                                 Glenn Chapman
                                                 MIT Lincoln Lab

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

Date:     Mon, 9 May 88 14:32 EST
From: <[e-mail]>
Sender: [e-mail]
Subject:  More on anti-matter

Paul Dietz writes the following on anti-matter:

>Antimatter might be effective in a beam weapon.

In a word, HAH!  Such a beam weapon would not work in the atmosphere, as
an interaction with matter will cause a minimum 1900 MeV explosion per
anti-proton annihilated (about 1 MeV if positrons are used instead).
Such a huge amount of isotropic energy added to the beam will disperse
it real quick, setting off more explosions.  This will all occur in or
just outside the nozzle!  If one attempts to vacate a small volume of
space for an anti-matter pulse to travel through, say with a high power
laser, the same problem arises, though with many orders of magnitude
(like about 25) lower integrated cross-section.  The same is true for
space based weapons, as the gas density is at least 1/cc and likelier to
be over 1000/cc.  Current matter particle beam research is arguably
feasible in that one has only collisions rather than the very high
energy annihilations leading to beam dispersion.

>An antimatter explosion would produce radiations not found in a
>conventional nuclear device. Decay of neutral pions would produce very
>energetic photons, and decay of charged pions produces muons.
>Annihilation of antimatter in nuclei might produce neutrons more
>energetic than those produced by fusion.

All that will be produced is a different energy spectrum of photons,
electrons, and neutrinos, as all of the other particles will decay or
annihilate on the order of a millionth of a second.  One MAY be able to
produce neutrons, but that would require anti-proton - proton collisions
of very high energy (and luck).  Such a branching is of very low
probability.

>Unlike conventional nuclear bombs, antimatter bombs can in principle be
>made as small as one likes, and are essentially fallout-free. A bomb
>containing a few tens of nanograms of antimatter might make an
>effective tactical radiation weapon (less if fusion reactions can be
>initiated), assuming handling problems can be solved. That might
>require the synthesis of higher antielements, but that's not obviously
>impossible.

This bomb will be as fallout-free as any nuclear device is.  The fallout
of any nuclear explosion is due to the irradiated matter around the bomb
being blown up into the atmosphere (this includes the containment
mechanism of the bomb itself).  It may be small, who knows the state of
current vaccum magnetic bottle experiments (extrapolated to room
temperature particle entrapment rather than solar core temperatures)?

J Storrs Hall writes:

>Hmmm.  It just occurs to me: how much antimatter would it take to
>ignite a lithium deuteride pellet?  or indeed something harder to fuse?
>One might get a signigicant power multiplier that way (assuming that
>antimatter is the critical-cost component).

If all one needs is 10 KeV, a single positron annihilation event is
enough energy (1 MeV), provided that it was placed properly.  This last
restriction would make things a bit more difficult.

The big problem with anti-matter is in the production.  As someone
stated earlier (and as was written up in a recent Science review),
anti-matter costs of order $10 million per milligram.  The problem is
getting it in a usable form.  SLAC, for example, has a 2 mile
accelerator to produce anti-particles.  Then one needs another 2 mile
accelerator to slow them down again so that they can be handled and
contained, provided they were travelling in the correct direction to
begin with!.  This all has to be done in a perfect vaccuum, otherwise
more 1900 MeV annihilations occur.  Fun stuff, this anti-matter!

Arnold Gill
Queen's University at Kingston
gill @ qucdnast.bitnet

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

Date:      Tue, 17-MAY-1988 12:03:31.00 PDT
From: <[e-mail]> (Steve Bougerolle)
Subject:   Re: Antimatter propulsion questions
To: <[e-mail]>


In issue #220, James W. Meritt asks several questions about matter/anti-matter
annihilation:

1) What about Pauli exclusion?  Does an anti-proton only react with free
   protons?

    Pauli exclusion only applies to identical particles.  A proton and
   anti-proton are NOT identical, so exclusion is entirely irrelevant. A
   proton and anti-proton (electron/positron, etc) can annihilate regardless
   of the presence of a potential.

2) Will anti-protons only react with free protons? Or does quark-quark
   annihilation take place?

    The reaction actually taking place IS quark-antiquark annihilation.
   But because of confinement rules, some reactions are more likely than
   others.

   Nevertheless, it is possible for antiprotons and neutrons to react.

   Similarly, anti-lithium will react with normal matter quite nicely.
   (Not just lithium; ALL matter).

So, NO, you can not store antimatter fuel in an aluminum container.
It has to be handled with more care than that.  However, you have to
MAKE antimatter before you worry about any of this; and this hasn't been
done.  What is actually proposed as a fuel?  Anti-hydrogen?

                                             -New in town

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

Date: Wed, 18 May 88 09:58 EDT
From: "Paul F. Dietz" <[e-mail]>
Subject: Re: Mars
To: [e-mail], [e-mail]

>     Remember that the Viking landers only sampled 2 places on all of Mars,
> and those weren't even the places where atmospheric pressure and water vapor
> content are thought to be highest.

It is not the case that the Viking sites were particularly dry compared to
other parts of the planet. Moreover, the measured partial pressure of water
was something like 14 precipitable microns, orders of magnitude too low for
liquid water to exist, even if saturated with salts.

>   They also did register some life-like
> reactions, which, while by no means being proof of life, deserve further
> investigation before being swept under the rug.

The results were hardly "life-like". They were much more consistent with
the presence of peroxides, superoxides, and ozonides in the soil. The
process that generates these compounds (photochemical dissociation of water
vapor) would operate globally, and dust storms would carry the chemicals
everywhere. It would be nice to confirm this model by further tests, but
claims that Viking did not present strong evidence against the existence of
life are misleading.

> Also, who is to say that life has to be organic? In _Genetic Takeover and
> the Origin of Life_ and also in a Scientific American article of a couple
> of years ago, A. G. Cairns-Smith makes a very respectable case for the
> hypothesis that the first life on Earth was in fact reproducing crystals
> capable of storing and transmitting genetic information and catalyzing
> metabolic reactions beneficial to themselves.

Cairns-Smith's very imaginative proposal is not supported by any evidence.
Moreover, his model requires the existence of liquid water.

>  Liquid water is not stable on Mars, but since frost (or maybe even
> snow) can form there and accumulate during the night and then be heated by
> the Sun when morning comes around, liquid water could exist transiently.

I believe this has been looked into. Frost does not form at night at the
Viking sites (although *seasonal* frosts do occur, probably by
precipitation of suspended ice grains), and any frost that did form would
sublime and not moisten the soil.

> Terrestrial microorganisms that use oxygen have enzymes to deal with
> oxidizing radicals and other nasty stuff. Considering that some
> cyanobacteria and archaebacteria are capable of growing in boiling sulfuric
> acid (which is a pretty strong oxidizer), and that other organisms have
> been shown to be able to grow in conditions which simulate Martian
> conditions, I would not be surprised if something found Martian conditions
> to be similar enough to its terrestrial niche to be able to adapt.

Those enzymes cannot operate if the organism has been lyophilized.  I view
with incredulity your claim that organisms have been found to grow in
conditions that simulate Martian conditions.  Perhaps you are refering
to very old experiments that were performed before it was realized how
cold and dry Mars really is?  Please give a reference.

    Paul F. Dietz
    [e-mail]

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

Date: 18 May 88 02:15:12 GMT
From: portal!cup.portal.com![e-mail]
Subject: Re: Naming the space station.

I second  motion to name a Space Station after the late and
sincerely lamented Robert A. Heinlein.
Anyone who cares at all about space probably cut their (<--non-sexist
'third person indefinite' pronoun) teeth on Heinlein's stories.

(-:"My opinions should be those of my employers":-)

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

Date: 18 May 88 06:06:49 GMT
From: portal!cup.portal.com![e-mail]
Subject: Re: "What if" on Shuttle External Tanks

Soviets salvaging Skylab...

I recall hearing the story at the time that the Soviets offered to boost
Skylab. And afterward, it was theirs. NASA was ready to agree, but the
idea got forcefully shot down by either the Pentagon or State Department.

Can anyone substantiate??

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

Date: 17 May 88 21:52:37 GMT
From: portal!atari!daisy![e-mail]  (Mike Wooding)
Subject: Re: Naming the space station.


 Perhaps ASIMOV:
     Astronauts Space Inhabitable Module for Orbiting Vacations.

 m wooding

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

Reply-To: pnet01![e-mail]
Date: Mon, 16 May 88 21:38:12 PDT
From: [e-mail] (Jim Bowery)
To: crash![e-mail]
Subject: Vocabulary lesson #9:  Spinoffs

Spinoffs, n, 1. $500 worth of research results proclaimed to justify the
$200,000,000,000 expenditure on NASA to date.  2. The central dogma in
rationalizing NASA worship and The Space Program to the uninitiated.
3. Teflon, computers, electronics, automobiles, houses, caves, the wheel,
sliced bread and anything else of a generally useful nature that NASA
had nothing to do with inventing.

UUCP: {cbosgd, hplabs!hp-sdd, sdcsvax, nosc}!crash!pnet01!jim
ARPA: crash!pnet01![e-mail]
INET: [e-mail]

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

End of SPACE Digest V8 #249
*******************