Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V11_3/V11_320.TXT

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Subject: SPACE Digest V11 #320

SPACE Digest                                     Volume 11 : Issue 320

Today's Topics:
        Human brain power (was Fermi paradox)
              Re: Dyson spheres?
                   Re: SETI
           Re: Need info on Space Stations
               Re: Power grid frequency
         Re: Apollo 13, STS-1, Vostok 1 anniversaries
           Re: Re: Dyson spheres, heat flow
               Re: Power grid frequency
          STS31 Launch Hold At T-31 Seconds
       Space Shuttle history/mission profile/dimensions
              Re: Decompression
            Re: Galileo Update - 04/17/90
           Re: Pegasus launch is a success!
----------------------------------------------------------------------

Date:       Wed, 25 Apr 90 14:33:50 EST
From: [e-mail]
Subject:    Human brain power (was Fermi paradox)

In SPACE_Digest V11 #298, [e-mail]
writes:

> Maybe the human brain can't create something smarter than itself.

There are those who believe that if the brain was simple enough to
understand itself, it would be too simple to understand itself.

John Coughlin    Net: [e-mail]   Vox: 613-541-6439   Fax: [phone]

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

Date: 26 Apr 90 01:30:31 GMT
From: thorin!homer![e-mail]  (Jonathan Leech)
Subject: Re: Dyson spheres?

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>Better would be to use absorbing sails (make them out of doped silicon and
>you've solved your power problems too!), which only give half as much thrust
>but don't have this particular problem.  Well, don't have it so badly, at
>any rate, given suitable coatings etc to reduce infrared re-emission inward.

    Or use conical sails which don't reflect light back at the
primary.  Admittedly larger sails would be needed since a lot of
radial thrust would be lost, and the issue of toasting other habitats
might arise, so placement would be more important.
--
    Jon Leech ([e-mail])    __@/
    ``You're everything I ever wanted in a human AND an extraterrestrial.''
    - Dr. Steve Mills in _My Stepmother is an Alien_

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

Date: 26 Apr 90 04:21:48 GMT
From: well![e-mail]  (Avery Ray Colter)
Subject: Re: SETI

[e-mail] (Steve Nuchia) writes:

>At one of my clients' offices there is a small poster, apparently
>once part of a magazine ad.  It is a picture looking across a
>mountain valley from the top of a very high, very rocky slope,
>looking over the handlebars of a motorcycle.  The caption:
>    "Never rule anything out."

Or, as my former roommate, a mountain bike racer in the team called FAT
(Finish Alive Team) would say:

FAT FACT #1:

The fastest way to accelerate:

DESCEND WITH CONVICTION!
-----------------------

--
Avery Ray Colter    Internet: [e-mail] | {apple|hplabs}!well!avery
     o/~ Mama, mama, mama, keep those skinny girls at home,
         o/~ `Cause this skinny boy wants a BIG FAT BLONDE!   - The Rainmakers

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

Date: 24 Apr 90 11:17:59 GMT
From: zaphod.mps.ohio-state.edu!sdd.hp.com!elroy.jpl.nasa.gov!zardoz.cpd.com!dhw68k!ofa123![e-mail]  (Mark Perew)
Subject: Re: Need info on Space Stations

Doesn't the "habitable volume" of an orbiter depend on the positioning
of the airlock?  If the airlock is mounted in the middeck it reduces
the "habitable volume" from what it would be if the airlock were
mounted in the cargo bay.



--
Mark Perew
...!{dhw68k,zardoz,lawnet,conexch}!ofa123!Mark.Perew                             [e-mail]
714 544-0934 2400/1200/300

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

Date: 25 Apr 90 16:30:14 GMT
From: pacific.mps.ohio-state.edu!zaphod.mps.ohio-state.edu!usc!elroy.jpl.nasa.gov!aristotle![e-mail]  (Peter Scott)
Subject: Re: Power grid frequency

I remember years ago reading that some ELINT satellites picked up interference
on a frequency of 60Hz while over North America, which changed to 50Hz as
they went over Europe...

This is news.  This is your       |    Peter Scott, NASA/JPL/Caltech
brain on news.  Any questions?    |    ([e-mail])

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

Date: 25 Apr 90 19:12:56 GMT
From: concertina![e-mail]  (Steve Hix)
Subject: Re: Apollo 13, STS-1, Vostok 1 anniversaries

In article <[e-mail]>, [e-mail] (Conor O'Neill) writes:
>
> Actually, "Ductape" is spelt "Gaffer Tape" in the UK.
> I wonder who invented it first?...  :-)

Ductape != Gaffer Tape

They look very similar, but use different adhesive backings.  (Gaffer
tape doesn't leave a sticky residue.)

As for who was first...

------------
"Up the airey mountain, down the rushy glen,
   we daren't go a-hunting for fear of little men..."
('cause Fish and Game has taken to hiring axe-carrying dwarves)

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

Date: Wed, 25 Apr 90 16:18:50 EDT
From: John Roberts <[e-mail]>
Disclaimer: Opinions expressed are those of the sender
    and do not reflect NIST policy or agreement.
Subject: Re: Re: Dyson spheres, heat flow


>From: uokmax![e-mail]  (Steven P Coltrin)
>Subject: Re: Dyson spheres, heat flow

>In article <[e-mail]> [e-mail] (John Roberts) writes:
>>Additional question: in "Ringworld", Larry Niven describes a cooling system
>>for use in a spaceship near a star - since cooling by radiation is impractical,
>>the waste heat is pumped to a collection point within the ship, from which it
>>will be dispensed when the ship is no longer near a star. Could this work, and
>>if so to what extent? I could make a guess, but that's all it would be.

>That would depend on how good your heat sink and pump (and insulation) were...
>and how much risks you want to take.

I was perhaps thinking of fundamental limits imposed by the laws of
thermodynamics. One plausible limit: if the power for your heat pump is
derived from a heat engine, and if the system is closed, then waste heat
storage will work only if the temperature of the storage location is kept
below the temperature of the heat engine's heat source.

>A better system occurred to me awhile ago; presuming the _Lying Bastard_ was
>fusion-powered (I don't remember if it was ever stated, even), then the power
>plant is going to be producing helium exhaust.  Just pump your waste heat into
>it and jettison.  Comments?

The reaction drives were fusion powered. Niven has been known to get numbers
wrong, sometimes by several orders of magnitude. Even near a star, most of the
sky is available for radiating heat, if you go about it the right way.
                           John Roberts
                           [e-mail]

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

Date: 26 Apr 90 03:03:18 GMT
From: fernwood!portal!cup.portal.com![e-mail]  (Mark Robert Thorson)
Subject: Re: Power grid frequency

A long time ago, a friend of mine and I experimented in communication
by driving an audio signal into the ground.  I had read an article, in
POPULAR ELECTRONICS, I think, about how this technique had been used
before radio was invented.

It involved driving an audio signal across two stakes (we used barbeque
skewers) pushed into the ground, several feet apart.  A similar setup
about 50 feet away (but with the amplifier reversed) picked up the audio
quite well.

Then we tried doing it over a distance of a quarter of a mile or so.
No luck.  The 60 Hz hum drowned out everything else.  The magazine article
said there was a line running down Africa where the hum changes from
60 Hz of the Americas to the 50 Hz of Asia and Europe.
.
1,$p

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

Date: 25 Apr 90 13:35:09 GMT
From: [e-mail]  (Technical Pub. Vince Short)
Subject: STS31 Launch Hold At T-31 Seconds

.  Countdown will hold at T-31 seconds due to a failure.                     .
.  Its the LO2 outboard fill and drain valve.                                .
.  Its LPC MPS8 and PD9 outboard fill and drain closed power is off, it should
be on.                                                                       .
.  Recommendation?                                                           .
.  We're in a no-go situation, we should have open power and we do not, er,
excuse me, closed power.                                                     .
.  And MPS can we verify that the valve is closed?                           .
.  Negative, we right now show an open position.  We can not verify that the
valve is closed.                                                             .
.  We have the closed power on and the open position off, we can try cycle one
time and try to pick up the closed position but ah we don't think its closed
power.                                                                       .
.  OK and MPS we have a message that we were blocked by a prerequisite
sequence DCL18.                                                              .
.  (Garbled)                                                                 .
.  Ah, holding 2 minutes.                                                    .
.  We're going to make an attempt to pressure(?) that valve closed, we've got
the (?) off, at this point we should be in good shape.                       .
.  I copy. Proceed.                                                          .
.  The valve is closed, we're go.                                            .
.  OK and we're (?) going to pick up here in the terminal sequence, MPS?     .
.  That's affirmative here, we're go, we're in good shape.                   .
.  OK you have a go to proceed.                                              .
.  GLS pick up the count immediately.                                        .
.  I copy.  Mark.  GLS is go for auto-sequence start.                        .
.  25 . . . 20 . . . 15 . . . Go for main engine start . .  T-6 . 5 . 4 . 3 .
2 . 1 . and liftoff.                                                         .
.  And NASA follows through with a picture perfect lift off and orbital
insertion of Discovery and its HST cargo.  So, can anyone out there interpret
what was going on here?  Was there a problem with the closure of the LOX fill
and drain valve?  Or was it a faulty indicator?  Or was it "blocked by a
prerequisite"?  And if it was is that a software glitch or what?  Anyone care
to explain?                                                                  .
.  The above was transcribed from a tape recording of the amateur radio
rebroadcast of Shuttle audio from Goddard Space Flight Center.  All acronyms
are questionable and I tried to pick out the content from in between the
statements by the announcer who kept speaking over the important
communications.  But perhaps it is good enough for someone who knows what's
going on to explain it to the rest of us interrested observers.              .
.                                                                            .
.                                         Joseph M. Fedock                   .
.                                         Technical Publications             .
.                                         Unisys Corporation                 .
.                                         Defense Systems/EISG/VFO           .
.                                         Paoli, PA 19301                    .
.                                         [phone]                     .
.                                         [e-mail]    .

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

Date: 26 Apr 90 01:03:18 GMT
From: ucselx.sdsu.edu!petunia![e-mail]  ( * * * Hunter * * * )
Subject: Space Shuttle history/mission profile/dimensions



I'm doing a report on the space shuttle and I need the following information
and I would be extremely thankful to anyone or group who could E-mail or post
the following information to me by Sunday:

    * History of the shuttle program (brief)
    * Shuttle mission profile (times/events/altitude/speed/etc.)
    * Shuttle/STS dimensions (i.e. dimensions for the shuttle, ET, SRB
          and complete assembly)
    * Chronology of shuttle missions, with listings of mission
      accomplishments and dates, launch times, shuttle missions, etc.

I know that this is a tremendous amount of information, but much of it is
_extremely_ difficult to come by, such as an accutate chronology of the missions
and a _precise_ mission profile.

Thanks in advance,
Mike.

#=============================================================================#
 |\_/| [e-mail] "PROGRAM: tr.v. To engage in a pastime
 {O o} [e-mail]   similar to banging ones' head against a
 ( " )  * Ack! Ack! Pfft! Ack! *   wall, except with fewer chances for reward."
   U   (Bill the Cat wants to get a space shuttle.)
 Admiral Michael "Hunter" Huang  +---<<< * * * S T A R   T R E K * * * >>>---+
 USS Ticonderoga, NCC-1736       +--<<< * * * * L I V E S ! ! ! * * * * >>>--+
#=============================================================================#

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

Date: 25 Apr 90 18:16:42 GMT
From: usc!elroy.jpl.nasa.gov!jpl-devvax![e-mail]  (Steve Jenkins)
Subject: Re: Decompression

In article <[e-mail]> [e-mail] (John Roberts) writes:
>Apparently the lungs contain compound which forms a foam, which in turn keeps
>the lung somewhat inflated even when you exhale. In certain medical conditions,
>this substance is missing, causing the lungs to collapse. The foam limits the
>degree to which you can exhale. I don't know what percentage of the total lung
>capacity this foam takes up, but barring further information, it seems best to
>just go ahead and keep your breathing passages open.

The surface tension of the alveoli is such that the lung itself would
collapse to near zero volume without external support.  In vivo, at
rest, the lungs maintain a mechanical equilibrium volume called
Functional Residual Capacity (about 3 l in adults) by adhering (again
by surface tension) to the chest wall.

The lungs do produce a surfactant that raises the compliance, making
them more distensible.  It is not a foam.

More to the point:  Transport of oxygen from lungs to blood is almost
entirely by diffusion.  If the partial pressure of O2 in alveolar gas
falls to zero, the arterial PO2 will rapidly fall below the minimum
necessary for consciousness.  After about 20 s of transport time from
lungs to brain, you black out.  Anyone who's ever (foolishly) taken a
few deep breaths from a helium balloon knows how fast it happens.

Holdling your breath to raise the PO2 will prolong consciousness;
Doing it without damaging the lungs would be tricky.

A good reference is the little book "Respiratory Physiology -- the
essentials" by John B. West (Williams & Wilkins).

--
Steve Jenkins N6UNI            [e-mail]
Caltech/Jet Propulsion Laboratory    [phone]

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

Date: 25 Apr 90 20:38:59 GMT
From: usc!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!IDA.ORG!pbs![e-mail]
Subject: Re: Galileo Update - 04/17/90

In article <[e-mail]>, [e-mail] (Ron Baalke) writes:
>                    GALILEO MISSION STATUS
>                        April 17, 1990
>
>
>           The Galileo spacecraft is 87,395,218 miles from
> Earth today traveling at 75,200 miles per hour relative to
> the sun. (deleted) It is on a trajectory back toward Earth
  for a gravity assist on its long journey to Jupiter.
>          (more deleted)
>           The maneuver recently completed and the upcoming
> maneuver in May make up the
> first of several maneuvers planned this year to shape the flight
> path for the flyby of Earth in December.
>
During flyby of Earth will Galileo be in position to study the Moon's
south polar region?  This area is one of the biggest question marks
remaining in our picture of the lunar terrain.  Detailed reconnaissance,
 if possible, will be useful in planning for future moonbases.

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

Date: 24 Apr 90 13:24:00 GMT
From: primerd!ENI!ENO![e-mail]
Subject: Re: Pegasus launch is a success!


Yet Another Pegasus Launching Idea...

Actually, the first time I saw a reference to "winch-launched"
Pegasi, I thought they meant like gliders:  a winch sitting on the
ground that accelerates a Pegasus sitting on the ground (well, on a
dolly) to a high speed.  Seems to me that a decent winch could get
our Peg up to several hundred miles per hour.

Advantages:

    o Really cheap (I assume big winches already exist)

    o Really simple -- no planes, no pilots, etc., just a winch, a
dolly, and a Pegasus

    o All your launching equipment is sitting on the ground (easy to
make repairs)

    o Unaffected by weather (assuming Pegasus cares less about the
weather than your average plane with a crew)

Disadvantages:

    o Pegasus still has to launch through entire atmosphere

    o Direction of launch is limited by where the winch is (let's put
it on a dolly too!)

Comments?

David Wolff
[e-mail]  or  [e-mail]
Disclaimer:  the above posting is not intended to represent Prime
policy.

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

End of SPACE Digest V11 #320
*******************