Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V09_3/V9_379.TXT

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Subject: SPACE Digest V9 #379

SPACE Digest                                      Volume 9 : Issue 379

Today's Topics:
               failures and engineering
             Re: Power vs Energy
              Re: Mir Evacuation
           Re: SETI: When and where to look
              Information wanted
             Re: failures and engineering
         Re: bored public, Three Mile Island
        Summary of manned and unmanned space missions
           Re: SETI: When and where to look
          Re: NSS Hotline Update for 4/14/89
----------------------------------------------------------------------

Date: 16 Apr 89 01:51:23 GMT
From: mailrus!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: failures and engineering

In article <[e-mail]> [e-mail] (Stuart Warmink) writes:
>> .................... The way you find out about these things is to try
>> them.  The major factor in how quickly you learn is how often you try.
>
>Another point of view is that with careful systems design and good engineering
>you don't need to learn from your mistakes. That is what engineering is all
>about. For instance, see the many successful Mariner, Pioneer, Voyager and
>Viking missions.

Yup, see them -- but study them properly.  Mariner 2, struggling past Venus
with one problem after another developing.  The early Pioneers, a total
disaster area.  Voyager 2, limping towards Neptune with its primary command
receiver dead and its backup one ailing (and don't blame this on the length
of the mission -- the problems developed almost immediately after launch),
not to mention the lubrication problems in the scan platform.  The Viking 1
lander, dead before its time due to human error back on Earth.

And let us not forget Seasat, with its slip-rings failing less than three
months after launch.  TDRS-1, with various electronic ailments fouling it
up to the point where it's been officially retired to standby status, now
that a replacement is finally in position.  Galileo, which is damned lucky
that it *didn't* fly in spring 1986, because its thruster system had *two*
disastrous design flaws, found only a few months ago, that would have made
it the most long-awaited and expensive failure in the history of planetary
exploration.  The GOES satellites, failing one after another as the lamps
in their scanner encoders burned out.

I repeat my comment:  the major factor in how quickly you learn is how
often you try.  It is *not* possible to get everything right the first
time.  NASA, ESA, etc. like to pretend otherwise, but the universe has
a habit of reminding them that they're wrong.
--
Welcome to Mars!  Your         |     Henry Spencer at U of Toronto Zoology
passport and visa, comrade?    | uunet!attcan!utzoo!henry [e-mail]

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

Date: 16 Apr 89 01:46:36 GMT
From: xanadu![e-mail]  (Michael McClary)
Subject: Re: Power vs Energy

In article <[e-mail]> [e-mail] (Jim Meritt) writes:
>In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>}In article <[e-mail]> [e-mail] (Jim Meritt) writes:
>}>Concur that power is an issue in general in space flight, but it should
>}>not be near the issue that ENERGY is.
>}
>}It depends on what kind of propulsion we are talking about.  With current
>}systems, yes, energy is the big problem.
>
>}Good question -- wait and see.  Hot fusion probably would; if you look at
>}artists' conceptions of things like inertial-confinement fusion rockets,
>}you'll see big radiator fins up forward.
>
>I sort of like the Discovery in 2001: A Space Odyssey.

Clarke originally specified big radiator fins for the Discovery.  They were
discarded when the image-makers pointed out that the half-informed would
start wondering about wings on a spacecraft, and this would distract them
from the rest of the movie, ruining their enjoyment.

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

Date: Sun, 16 Apr 89 09:16:32 PDT
From: Peter Scott <[e-mail]>
Subject: Re: Mir Evacuation

aero!venera.isi.edu![e-mail]  (Craig Milo Rogers) writes:

>    The Soviet space station Mir will stay in mothballs for three
>months because of delays in preparing equipment that cosmonauts need
>to perform experiments aboard the spacecraft, Soviet news reports
>said.  ...  "The facility will be left unmanned ... due to delays with
>the preparation of two research modules" that will be attached to the
>main craft, Deputy Flight Director Viktor Blagov told the Tass news
>agency.  This was the first explanation of why the project was being
>suspended.

This is starting to sound like Skylab... anyone know how often Mir has
to be reboosted?

Peter Scott ([e-mail])

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

Date: 16 Apr 89 15:42:06 GMT
From: ius3.ius.cs.cmu.edu![e-mail]  (David Pugh)
Subject: Re: SETI: When and where to look

In article <[e-mail]> [e-mail] writes:
>For this method to work there must be a planet with intelligent life on
>the same event surface as we. Does anyone out there know how many stars lie
>on our event surface of supernova 1987a?
>
>Does this idea make any sense, or am I just blathering?

Probably lots -- 1987a was ~160,000 light-years away.

It's a neat idea, unfortunately it has the problem of the delay for
signal propagation from us to wherever. If we started transmitting
as soon as we saw 1987a, then the closest star wouldn't hear from us
for over three years.

There are two ways to get around this, however. The first would be to,
on detecting a major event, start broadcasting immediately in the opposite
direction (on the assumption that anyone "farther away" will aim their
radio telescopes at 1987a and detect us). Another would be to generate
a noticeable event and then start broadcasting (now that we've got your
attention...). Of course, if you could generate a noticeable event, why
bother with radio. Just trigger a series of novas in a ascending sequence
of prime numbers....
--
Never be angry when a fool acts like a        David Pugh
fool.  It's better when fools identify        ....!seismo!cmucspt!cat!dep
themselves...it removes so much uncertainty.
            --Lord Peace
--

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

Date: 16 Apr 89 08:03:24 GMT
From: ncrlnk!ncrcae!hubcap![e-mail]  (james e lynch)
Subject: Information wanted

A
I am looking for information on the amount of Dose that the astronauts received on their flight.  Information on the proton flux would also be very useful.  Finally, could anyone comment on the possibility of the embryo deaths being due to radiation damage.  I heard that there was an increase proton flux, due to solar activity and due to a geomagnetic storm. Reply to


                 [e-mail]

since I do not subsribe to this new service.

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

Date: 16 Apr 89 17:16:49 GMT
From: prism![e-mail]  (Matthew DeLuca)
Subject: Re: failures and engineering

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>In article <[e-mail]> [e-mail] (Stuart Warmink) writes:
>>> .................... The way you find out about these things is to try
>>> them.  The major factor in how quickly you learn is how often you try.
>>
>>Another point of view is that with careful systems design and good engineering
>>you don't need to learn from your mistakes. That is what engineering is all
>>about. For instance, see the many successful Mariner, Pioneer, Voyager and
>>Viking missions.
>
> [Long history of Western space failures here.  I would assume that Soviet
   craft never fail, from this list.  Removed for brevity's sake.]
>
>I repeat my comment:  the major factor in how quickly you learn is how
>often you try.  It is *not* possible to get everything right the first
>time.  NASA, ESA, etc. like to pretend otherwise, but the universe has
>a habit of reminding them that they're wrong.

I see.  So, according to your hypothesis, the Soviets you so dearly love should
by now have colonized Mars, instead of scratching their heads and wondering
why their probes fail one after another.  They've been sending probes one after
another for twenty-five years now, and have yet to have one work properly.
Experience is an excellent teacher; in the early years of space exploration,
there was no substitute.  But this is 1989, not 1959.  We've sent out our
dozens and dozens of probes, and we've learned from our mistakes.  Today, there
is *no substitute* for solid engineering; Stuart is absolutely correct.  For
some reason, the Soviets seem to have failed to realize this.

I noticed that in your roll call of broken satellites and probes, you included
Voyager 2.  This is a perfect example of how a space probe should be designed;
*in spite* of the fact that there are point failures on board, it *still
works*.  Voyager is out there laying the groudwork for the future exploration
of the solar system, and you're sitting here on Earth complaining about the
lube job.  I feel sure that if it had been a Soviet probe, you'd be singing
it's praises almost daily.  In the end, all I can say is that while the Soviets
keep sending probes out, "gaining experience", we're the ones with the
working spacecraft.


--
--------------------------------------------------------------------------------Matthew DeLuca                      :
Georgia Institute of Technology     : Certainty is the lot of those who
ARPA: [e-mail]      :           do not question.
--------------------------------------------------------------------------------

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

Date: 16 Apr 89 18:38:20 GMT
From: hp-pcd!hpcvlx![e-mail]  (Greg Goebel)
Subject: Re: bored public, Three Mile Island

>       I just want to know how many of these technology haters are running
> home to their CD players and microwaves and have 150 clear channels beamed
> to them from the netherworld...
>
>       Peter...
>       [e-mail]
>       University of Rochester

The most extreme example of anti-technological nonsense I ever saw was the lady
English Lit professor I once met who was extremely indignant because many
modern writers were using word processors.

I didn't say anything.  I was much too astonished.  I thought later that the
only response I could've made was:  "You're natural and organic.  You use an
electric typewriter."  But arguing with such people is both rude and futile.

Nowdays, I have my stock answer:  "On a scale of 1 to 10, how do you rate
the importance of this issue?"

The SF writer John Varley once wrote a throwaway story in which he was the
protagonist.  He was trying to get his publisher to advertise his books as
"Varleyarns! -- 100% composed by hand -- No word processors used!"  The
difference between Mr. Varley and my lady professor acquaintance was that
Varley was being ridiculous on purpose.

    +---------------------------------------------------------------------+
    | Greg Goebel                                                         |
    | Hewlett-Packard CWO / 1000 NE Circle Boulevard / Corvallis OR 97330 |
    | [phone]                                                      |
    | INTERNET: cwo_online@hp-pcd                                         |
    | HP DESK:  CWO ONLINE / HP3900 / 20                                  |
    +---------------------------------------------------------------------+

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

Date: 17 Apr 89 04:26:41 GMT
From: vax5![e-mail]
Subject: Summary of manned and unmanned space missions

Does anyone know if there exists somewhere an electronic summary of the
specs and results of manned an unmanned space missions to date?

I'm interested in enlarging my very patchy knowledge of early space
missions.  Any information (or the title of a good book on the subject)
would be greatly appreciated.

Eric Weisstein

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

Date: 17 Apr 89 04:45:27 GMT
From: well![e-mail]  (Tom Neff)
Subject: Re: SETI: When and where to look

In article <[e-mail]> [e-mail] writes:
>Is there a similar space-time marker in the galaxy? I think a supernova
>explosion might qualify. The light from the explosion travels outward as a
>spherical front. Thus, the "event surface" is a spherical shell traveling
>outward from the supernova. An intelligent creature might reason as follows;
>"If I see a supernova go off, I'll calculate it's exact coordinates. Then
>I'll start broadcasting to every other star on my event surface (i.e., at
>the same distance as I am from the supernova). If other intelligent creatures
>get the same idea, and they lie on my event surface, they'll start
>broadcasting to me also. I'll be sure to meet a girl that way!"

My goodness, it has been quite a while since I read a brilliant original
thought on the net.  Give this man a cigar!  (Or a tofu snack since this
is the 80's.)  I like it.  I don't have the number he wants, but I do
have two thoughts in followup:

 * Since we want the intersection of two spherical shells you actually
have a toroidal locus to deal with.  I'm not even sure any of it
intersects our galaxy, since 1987A is in the Magellanics.

 * To be any fun, this idea needs to use smaller, more local events.
The problem is that each anomalous occurrence like a nova only defines
a thin torus of candidates for any given star.  What one needs is
something that happens to lots of stars but is still unmistakeable.  I
suggest long term variable star minima.  Every one defines an event
torus, and there's a new one every day, week, month or year, depending
on how close to home you want to stay.
--
Tom Neff                  [e-mail]
                       or [e-mail]

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

Date: 17 Apr 89 05:29:44 GMT
From: well![e-mail]  (Tom Neff)
Subject: Re: NSS Hotline Update for 4/14/89

In article <246900021@cdp> [e-mail] writes:
>
>This is the National Space Society's Space Hotline for the week ending
>April 14, 1989.

It's also a sprinkling of warmed over AP headlines atop an indigestable
goo of political tub thumping.  >>YECCCCHH!<< as MAD used to say!

>The Soviet Union has decided to temporarily vacate the Mir space station;
>a move that was prompted by delays in the preparation of two new modules
>for the soon-to-be vacant platform.  Flight Director Viktor Blagov stated
>that the station will only be unmanned for several months until the two
                        ^^^^^^^^^^^^^^
                        remember this!
>research modules are completed and ready for launch. ...
>             The development may provide the U.S. with an opporunity to
>gain the high ground regarding the civilian space program in general and
      ^^^^^^^^^^^
      in several months??
>international cooperation specifically.  While the Soviets had taken
>advantage of the Challenger accident to attract international partners,
>arguments can now be made that it is the U.S. and not the Soviets that
>can be counted on in the long run to stand by their commitments to human
>expansion into the solar system.

I don't know whether to laugh or cry reading this.  If the
international community wanted to draw any conclusions at all from the
Mir hiatus, and it doesn't seem to me they really should, it would be
that NEITHER of the original space dinosaurs can be trusted, and it's
time to flock to Japan/Ariane/Long March.  The US could not be *less*
poised to make hay out of anything the Soviets do or don't do in
space at the moment.  Our little manifest is backlogged for years.

>The action also points out the importance of building a fully capable
>space station such as the International Space Station Freedom.

***SURPRISE!!***

Never guessed that was coming, didyuh Vern? [Behave, Tom...]

>                                The Mir
>space station had greatly reduced capabilities allowing for limited
           ^^^
           Note past tense here!
           Obits, get me rewrite...

>research in life sciences and materials processing...

The fun question here is, reduced from what?  From what the US
Space Station is supposed to be if we ever build it?  That's
creative use of the language.

I deleted the beltway blather comprising the remainder of what
should by rights be a talk.politics article, not sci.space.
Give me a break.

--

Thought on Space Station FREEDOM: If they reactivated Vandenberg
to launch Station modules on unmanned shuttles, could we rename
the launch facility the MAXI-PAD??

--
Tom Neff                  [e-mail]
                       or [e-mail]

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

End of SPACE Digest V9 #379
*******************