Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V09_5/V9_568.TXT

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Date: Sun, 30 Jul 89 03:17:43 -0400 (EDT)
Subject: SPACE Digest V9 #568

SPACE Digest                                      Volume 9 : Issue 568

Today's Topics:
            Re: Lagrangian Points
            Mail, Voyger downlink
               The Russians are coming!
             Re: Apollo 11 program alarms
           Re: Apollo 8, 9, and 10 and Apollo books
        Martian enigmas in back issues of SPACE digest
              Re: S-Band Beacon on Moon
           Voyager Status for 07/18/89 (Forwarded)
    Re: Apollo Books (was Re: Apollo 12 (And Surveyor 3))
             Re: Apollo 11 program alarms
Re: Apollo-11 lunar experiment still useful after 20 years (Forwarded)
               Re: Apollo 8, 9, and 10
----------------------------------------------------------------------

Date: 19 Jul 89 16:37:02 GMT
From: mailrus!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Lagrangian Points

In article <[e-mail]> [e-mail] (Gregory Harrison) writes:
> ...There was, and may still be, a satellite placed at the libration point
> between the Earth and the Sun, and set into an orbit about the line between
> the Earth and the Sun such that when viewed from the Earth (with appro-
> priate equipment, not eyes, of course) the satellite would circumscribe the
> borders of the Sun.  NASA had redirected this satellite into that orbit
> after it had completed some other mission.  Perhaps it was called
> Solar Max, I can't recall...

This is a little garbled.  ISEE-3, the third International Sun-Earth Explorer,
was placed in such a "halo orbit" by design.  While the collinear Lagrange
points are not stable, there are "orbits" around them, in planes perpendicular
to the axis connecting the two major bodies, which are *almost* stable, i.e.
only occasional small corrections are needed to stay in them.  ISEE-3 was
parked in a halo orbit around the sunward Lagrange point to give its
instruments a look at the solar wind upwind of Earth.  The halo orbit is
actually large enough that the line of sight to the satellite was well
clear of the Sun, which was just as well for efficient communications!

ISEE-3 was built for that job.  However, late in its life it was rechristened
ICE, the International Comet Explorer, and was redirected to an encounter
with comet Giacobini-Zinner.  This was the best the US could do for a comet
mission, all attempts at funding a US Halley mission having failed.  ICE's
instruments were designed for solar-physics work, but could return enough
useful data about the comet's tail that the diversion was thought worthwhile.
Getting ICE out to G-Z was quite a trick, involving an elaborate series of
maneuvers, several lunar flybys, and orbits that look truly bizarre.  But
it did all work, and ICE made the very first comet encounter, some months
before the Soviet/Japanese/European flotilla of custom-built probes arrived
at Halley.
--
$10 million equals 18 PM       |     Henry Spencer at U of Toronto Zoology
(Pentagon-Minutes). -Tom Neff  | uunet!attcan!utzoo!henry [e-mail]

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

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Date:     Wed, 19 Jul 89 11:45:18 -0900
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From: "ROBERT J HALE"  <[e-mail]>
Subject:  Mail, Voyger downlink

   First thing I have to say is "Your back?"   Long time since I have had
space digest in my mail box.  Something is working.  Only problem is my
space plane digest is not getting here.  If any one of you is on that digest
please mail in an complant for me.

  Joe Beckenbaw:   Get in touch with me.

  Now a question.   Is there a satellite west of 80deg (satcom F4 is the first)
that is covering the NASA photos of the Voyger data.   I heard that there was
one that NASA was using but can't find it.   Must be to far east.   From
Alaska the view is about 79deg or more west or I can't see the bird.  Busy
summer.

   Thanks in advance.     Robert J. Hale III
                          ISECCo Director.
                          FNRJH@ALASKA
                          "If you don't get a reply rememberler struck again"
                           The mailer has struck.  Try again.
                           Include USnail address.  RJH"

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

Date: 19 Jul 89 23:32:13 GMT
From: oliveb!amdahl![e-mail]  (T.S. Reddy)
Subject: The Russians are coming!


    TO NORTH AMERICA AT LEAST!

    I saw an ad in this week's "Aviation Week" that the Soviets will be there
with the Mig-29 and other planes at an airshow in British Columbia, Canada.
The AN-225 is also a possibility.
    The show will be around August 8th.
    Check out the magazine!
--
T.S.Reddy

Arpa: [e-mail]
uucp:...!{ames,decwrl,uunet,pyramid,sun}!amdahl!reddy

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

Date: 19 Jul 89 11:55:28 GMT
From: thorin!lhotse![e-mail]  (James Symon)
Subject: Re: Apollo 11 program alarms

In article <[e-mail]>, [e-mail] (Charlie Richter) writes:
>
> And the answer is ... Steve Bales.  Bales was the
> guidance officer for Apollo 11.  As such, he was the
> person who gave Eagle the GO to land despite the 1202
> and 1201 program alarms.
> --

In that CBS special it appeared that Armstrong made that decision. He
said something to the effect, "Hang tight, we're going" and just kep
going when the program alarm came up.

jim
[e-mail]
{decvax uunet}!mcnc!unc!symon

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

Date: 19 Jul 89 16:26:34 GMT
From: janus![e-mail]  (Blake Philip Wood)
Subject: Re: Apollo 8, 9, and 10 and Apollo books

Eugene Cunningham's book about the Apollo program (I forget the title)
provides an interesting perspective on several issues which I've not
seen elsewhere.  Cunningham, if you'll remember, flew on Apollo 7.

According to him, the crews of the Apollo flights were basically decided
early on, without particular regard to what the flight missions were.
For a long time Apollo 12 was to have been the first moon landing, but
the successes of the earlier flights allowed NASA to move it up to
Apollo 11.  Cunningham states that the smart money within NASA (and
there were bets made) was placed on Charles Conrad to do the first
moonwalk.  As it turned out, Conrad made the third moonwalk on Apollo 12.


                 Blake P. Wood - [e-mail]
                 Plasmas and Non-Linear Dynamics, U.C. Berkeley, EECS

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

Date:     Wed, 19 Jul 89 15:02 EST
From: <[e-mail]>
Subject:  Martian enigmas in back issues of SPACE digest

While reading some postings from SPACE digest, I noticed a
couple of references to the enigmatic structures
(city, face) on Mars.

My question is: Have these structures been discussed at any length
on this digest, and if so, in what volumes may I find them?

Thanks in advance,
GRAHAM@IUCF

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

Date: 19 Jul 89 17:20:24 GMT
From: mailrus!jarvis.csri.toronto.edu!utgpu!attcan!lsuc!atha![e-mail]  (Lyndon Nerenberg)
Subject: Re: S-Band Beacon on Moon

In article <[e-mail]> [e-mail] (Henry Spencer) writes:

>As far as I know, all the Apollo lunar-surface transmitters were shut
>down when the Apollo seismometer network was shut down (to save some
>trifling amount of money!!! :-[ ) some years ago.  I could be wrong.

Eh? Was ConEd charging NASA for the power produced by the (moon-based)
nuclear reactors?
--
Lyndon Nerenberg  VE6BBM / Computing Services / Athabasca University
    {alberta,decwrl,ncc}!atha!lyndon || [e-mail]
        If everyone quit smoking, drinking, and buying gas,
               the nation would probably go bankrupt.

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

Date: 19 Jul 89 17:46:55 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: Voyager Status for 07/18/89 (Forwarded)


                    Voyager Status Report
                        July 18, 1989


     Neptune's new moon, 1989 N1, is becoming a new guidepost

for the Voyager navigation team and is a candidate to help
better determine the location of Neptune itself.

     Neptune was discovered in 1846, and the planet takes 165

years to orbit the Sun; thus, Neptune won't return to the
position where astronomers first saw it until 2011.  This
leaves great uncertainty in the precise knowledge of
Neptune's orbit that Voyager navigators need to get the
spacecraft to the targeted area of the planet at the right
time.  But the new Neptunian moon, 1989 N1, will provide the
navigation team with a better idea of Neptune's exact
location.

     The discovery of the moon fulfilled expectations of
Voyager navigators who were hoping to find at least one new
object in the Neptune system whose orbit could potentially be
used to gauge the relative positions of Triton, Neptune and
various background stars, said Don Gray, Voyager Navigation
Team Chief.

     Many of the images coming back from the spacecraft are
optical navigation frames.  Ideally, the frames show a moon
against a field of stars.  Using stars as dim as 10th
magnitude as reference points, the Voyager navigators
progressively update and refine the location of Neptune and
its moons.  This new information is then integrated into
commands that adjust Voyager's flight path and retarget the
spacecraft's observations, if necessary.

     The next trajectory correction maneuver is being
designed and will be uplinked to the spacecraft late next
week.  The maneuver is one of the final three that will be
conducted between now and closest approach to bring the
spacecraft within about 100 miles (150 kilometers) of the
point at which it's aimed -- about 3,000 miles (4,850
kilometers) from Neptune's cloud tops.


DISTANCE TO EARTH:  2,686,949,000 miles
DISTANCE TO NEPTUNE:  33,805,000 miles
HELIOCENTRIC VELOCITY: 42,192 mph

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

Date: 18 Jul 89 13:39:28 GMT
From: mcvax!ukc!icdoc!ist![e-mail]  (Kevin Holmes)
Subject: Re: Apollo Books (was Re: Apollo 12 (And Surveyor 3))

From article <[e-mail]>, by [e-mail] (Andy Clews):
>
> [deleted]
> Does anyone have a list of books that specialise in the Apollo
> series? Authors, publishers, ISBNs, etc. would be useful
>
> Andy Clews, Computing Service, Univ. of Sussex, Brighton BN1 9QN, ENGLAND

Can I echo Andy's plea with a particular reference. When I was in school
(~76) the town library had a brilliant book on Apollo in it's reference
section. As far as memory serves me it was actually published by NASA. It
was about 14" by 18", approx 250 pages, full colour photographs and actually
quite technical in detail. As for any other details, memory fails me,
can anybody help?

Cheers,

Kev Holmes     [e-mail] | "Selling software is just like
Imperial Software Technology |  prostitution; You've got it, You sell it,
Reading, Royal Berkshire, UK |  You've still got it!" - D. Lambert IST.

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

Date: 19 Jul 89 23:07:47 GMT
From: mailrus!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Apollo 11 program alarms

In article <[e-mail]> [e-mail] (James Symon) writes:
>> And the answer is ... Steve Bales.  Bales was the
>> guidance officer for Apollo 11.  As such, he was the
>> person who gave Eagle the GO to land despite the 1202
>> and 1201 program alarms.
>
>In that CBS special it appeared that Armstrong made that decision. He
>said something to the effect, "Hang tight, we're going" and just kep
>going when the program alarm came up.

Nope, wrong -- it was the people back in Houston, and Bales in particular,
who decided that the problem wasn't serious enough to justify an abort.
Half a dozen sources, including official NASA ones, all agree on this.
CBS is mistaken.
--
$10 million equals 18 PM       |     Henry Spencer at U of Toronto Zoology
(Pentagon-Minutes). -Tom Neff  | uunet!attcan!utzoo!henry [e-mail]

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

Date: 20 Jul 89 02:03:47 GMT
From: aramis.rutgers.edu!klaatu.rutgers.edu![e-mail]  (J Storrs Hall)
Subject: Re: Apollo-11 lunar experiment still useful after 20 years (Forwarded)

Wayne Hayes writes:
    >     Once the laser beam hits [the Apollo 11 corner reflector]
    >....  The reflected light is too weak to
    >be seen with the human eye, but under good conditions, one photon
    >-- the fundamental particle of light -- will be received every
    >few seconds.

    Is this right? I would think that many more than that would get back.
    Besides, if you only got one back every few seconds, it would be
    useless for the accuracy of timing needed to calculate the moons
    distance with "unprecedented accuracy".

Hmm.  Paul Deitz please check :^), but my blackboard claims:
A 100 mW beam (Edmund Scientific league) = 1 million ergs/sec.
at one micron wavelength E=hv gives 1.5e26 photons/sec.
If the beam is one mile square at the moon and one square foot
hits the reflector, divide by 2.8e6 giving 5.4e18, and similarly for
the return trip (use a square foot telescope) giving 2e11 photons/sec.
since c is 3e8m/s, your return beam is averaging 660 photons/meter,
with which you should be able to measure the distance to within an inch.
--JoSH

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

Date: 19 Jul 89 17:24:25 GMT
From: b.gp.cs.cmu.edu![e-mail]  (Ralf Brown)
Subject: Re: Apollo 8, 9, and 10

In article <[e-mail]> [e-mail] (Doug Davey) writes:
}Does anybody remember whether the ascent or descent engine was used
}during Apollo 10's return from low orbit to rendezvous with the CSM?
}Either option seems difficult.  On the one hand, I would not expect
}the descent engine to be restartable.  On the other, firing the
}ascent engine and getting the ascent stage cleanly separated from the
}descent stage would be tricky since the descent stage was deigned to
}be firmly on the lunar surface during this operation.

As I recall, one contingency plan was in fact such a separation while not
on the surface, in case they ran out of fuel trying to land.  They would
then separate immediately and use the ascent stage to abort back to the
CSM.
--
{backbone}!cs.cmu.edu!ralf   ARPA: [e-mail]   FIDO: Ralf Brown 1:129/46
BITnet: RALF%CS.CMU.EDU@CMUCCVMA   AT&Tnet: [phone] (school)   FAX: ask
DISCLAIMER?  Did  |"Let both sides invoke the wonders of science instead of
I claim something?| the terrors." --John F. Kennedy

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

End of SPACE Digest V9 #568
*******************