Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v09_4/v9_429.txt

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Subject: SPACE Digest V9 #429

SPACE Digest                                      Volume 9 : Issue 429

Today's Topics:
           Re: DO IT YOURSELF SPACE-PROBES?
              Re: SETI question
Re: NASA selects contractor to develop Advanced Solid Rocket Motor (Forwarded)
        Re: funding large scale space hardware
            Re: Citizens in Space
       Re: Final Frontier June 1989....EXCELLENT ISSUE
          Re: Spaceplane mailing list--where is it?
        Re: Does anyone know *why* the USAF did this?
        Re: Does anyone know *why* the USAF did this?
----------------------------------------------------------------------

Date: 9 May 89 21:20:08 GMT
From: mailrus!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: DO IT YOURSELF SPACE-PROBES?

In article <[e-mail]6> [e-mail] writes:
>... Could someone with the technical know-how build a
>useful satellite out of components bought at the local Radio Shack
>and hardware store? ...

Yes, it can be done, especially if you do not insist on the thing being
able to run ten years without maintenance or working 100% the first time.
(Unfortunately, the high costs and limited schedule of current launches
strongly push you in that direction.)

>... Do not subject the equipment
>to excessive vibration - more of a problem with our hypothetical
>space probe.

Vibration and acceleration during launch are an issue, although not too
severe.  Human beings, after all, ride those things with no problem.

>     What about heat - the cooling fan in my PC wouldn't be much
>use in a vacuum. How do you control the temperature of electronics
>in space, to prevent them from overheating? How do you tell
>whether they are in danger of overheating? ...

Cooling *is* a problem.  Rumor hath it that some of the Soviet satellites
simply are pressurized with cooling fans inside.  This does simplify life.
The alternative is to use conduction cooling, with things like "cold rails"
carrying heat out by contact.  The way you tell is by modelling and (if
you have the chance) vacuum-chamber testing on Earth, assuming that you
don't have the chance to fly multiple attempts.  It's non-trivial.

>... What kind of radiation fields and
>particle fluxes would you encounter in LEO? Clark orbit? Wherever
>Magellan is at the moment? How would you deal with them?

LEO, nothing terribly serious, especially if you're in a low-inclination
orbit away from the South Atlantic Anomaly (an area where the inner Van
Allen belt is especially close to Earth).  Clarke orbit, fairly significant
because it is in the fringes of the outer Van Allen belt.  In-between
orbits are still worse, which is why you don't see them used much.
Interplanetary space, not very serious unless a major solar flare occurs.
Near encounters with Jupiter, the less said the better. :-) :-)

As for how you deal with them, basically you use radiation-hardened
components (which are available commercially but at scandalous prices),
try to select off-the-shelf parts which are fairly radiation-resistant,
provide redundancy when possible, and occasionally shield crucial items
a bit.  Basically, any useful overall shielding is too heavy, so the
electronics just has to sit there and take it.


The primary amateur satellite folks, so far, are the radio amateurs,
who have built and operated a dozen or so satellites quite successfully.
There have been little bits of interest from other groups, so far with
no actual flying hardware to speak of.  There was a bunch called the
Independent Space Research Group that was planning an Amateur Space
Telescope (on a smaller scale than the HST!); haven't heard how they're
doing lately.  There has been persistent talk about an Amateur Lunar
Polar Orbiter, as the mission doesn't seem significantly harder than
putting an amateur comsat in Clarke orbit and the payoff (to science
and to people interested in lunar bases and colonies) would be high.
The World Space Foundation has been working, slowly, on a prototype
solar-sail test spacecraft.  There are others.
--
Mars in 1980s:  USSR, 2 tries, |     Henry Spencer at U of Toronto Zoology
2 failures; USA, 0 tries.      | uunet!attcan!utzoo!henry [e-mail]

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

Date: 9 May 89 18:19:01 GMT
From: visdc![e-mail]  (John E Van Deusen III)
Subject: Re: SETI question

In article <[e-mail]> (Eric Gorr) writes:
> I was just wondering...we are pumping all kinds of money into seti
> research and I was wondering what extra is comming out of it.

I recently saw a discussion on CNN between Carl Sagan and Ted Turner.
Dr. Sagan said that SETI is 100% privately funded, primarily by the
Planetary Society.  In his opinion we were not getting much for the
money that we are pumping into SDI.  Dr. Sagan wanted to know why the
media did not expose SDI as a fraud; especially the way it was, and
still is, being sold to the public.  Mr. Turner made the observation
that it is impossible for a television station owner not to become rich,
so the media always represents the point of view of the wealthy.
--
John E Van Deusen III, PO Box 9283, Boise, ID  83707, [phone]

uunet!visdc!jiii

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

Date: 9 May 89 03:13:02 GMT
From: hpda!hpcuhb!hpcllla!hpcllmv![e-mail]  (Jeff Caldwell)
Subject: Re: NASA selects contractor to develop Advanced Solid Rocket Motor (Forwarded)

>     Lockheed is teamed with Aerojet Space Booster Co.,
>Sacramento, Calif., as its principal subcontractor on the ASRM
>program, and Rust International, Birmingham, Ala., as its facility contractor.
              ^^^^

Pretty scary name if you ask me.  Are they subcontracting out to Corrosion
Products Inc. and Deterioration Development also?:->

        Jeff Caldwell

Disclaimer: The opinions presented herein are my own and by no means are
            those of my employer.  My opinions are also better than yours.

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

Date: 10 May 89 05:15:04 GMT
From: jarvis.csri.toronto.edu!utgpu!bnr-vpa!bnr-fos!leibniz![e-mail]  (Stanley Chow)
Subject: Re: funding large scale space hardware

In article <[e-mail]> [e-mail] (John B Scalia) writes:
>In article <[e-mail]> [e-mail] (Henry Spencer)
>writes:
>>[mucho deletions]
>>
>>Boeing spent $1 billion of its own money on the 747.  (Note:  not even
>>borrowed money, *its own* money.)  And did the same thing again with
>>$2 billion for the 757 and 767.
>
>True, Henry. However, and I believe the Boeing people could respond to this,
>the 747 series was originally designed for a DOD request for a large troop/
>cargo carrier. Boeing lost to the C-5 design. Essentially, they were then
>stuck with a huge craft which most knowledgable aircraft people predicted
>would be a white elephant in the commercial sector. Obviously, these
>people were wrong. Thus, Boeing didn't design it for altruistic reasons.

I am sure Henry will correct you, but I so rarely get to post on this
group :-)

Boeing designed the 747 for long-haul pessanger traffic. As I understand
it, the 747 was designed more or less to spec. for PanAm.

This, of course, does not make it any more "altruistic". Boeing fully
intended to make money from the 747 (or any other plane it has ever made).
But, why is that a problem? Isn't that the American way?

If there is enough traffic (space traffic, that is), I am sure Boeing will
be happy to invest billions of dollars on a launch vehicle. The only question
is: How much traffic will there be? How soon will the traffic develope? How
much is it worth to the world?

If you answer little, long time, little to those questions, then of course
neither Boeing nor any other company will invest. On the other hand, there
are people who answer the questions differently.


Stanley Chow        BitNet:  [e-mail]
BNR            UUCP:    ..!psuvax1!BNR.CA.bitnet!schow
[phone]             ..!utgpu!bnr-vpa!bnr-fos!schow%bnr-public
I am just a small cog in a big machine. I don't represent nobody.

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

Date: 9 May 89 17:17:34 GMT
From: asuvax!anasaz![e-mail]  (Scott Gibson)
Subject: Re: Citizens in Space

In article <[e-mail]> [e-mail] (Andrew D Williams) writes:
>one of the things they stress here is our professionallism.  I was appaled
>at the Challenger incident.  First because it happened at all but more
>importantly at the fact that the family of the officers were sueing the
>government.  I am sorry but that is wrong.  I am going to make a pledge to

I, too, was appalled and astounded that anyone could be surprised that
space flight is *dangerous*.

>attention) The fact that the families of the officers, sworn to the country
>sued shows that there is no way that there is no way we should put (pardon
>me) normal citizens into space.  Not yet.  All of Matt's arguements about

The fact that lawsuits are possible is certainly a concern; however, I
don't follow your argument.  You state that because families of MILITARY
OFFICERS sued, then CIVILIANS should be prohibitted from space.  It
would seem that military family attitudes have changed dramatically
since the days of Mercury/Gemini/Apollo - they now more closely match
those of their civilian counterparts (remember that civilian test pilots
were included in the original space program).

It seems clear that what is needed is an understanding on everybodies'
part that the space program is a dangerous undertaking, regardless
of whether it's NASA or a private enterprise, or who (if anyone) is
participating.  And to (hopefully) hold off the proponents of unmanned
space exploration:  *Everyone* should be able to see that the goal
of even the unmanned program is to eventually put people (military/
civilian) in space.

I applaud your sentiments regarding the lawsuits.  I personally feel
that if NASA had asked for more volunteers for a launch the day after
the Challenger incident, they would have had no problem filling
shuttle seats with enthusiastic space travellers.

Scott

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

Date: 9 May 89 18:41:24 GMT
From: hpfcdc!hpfcdj![e-mail]  (Bob Myers)
Subject: Re: Final Frontier June 1989....EXCELLENT ISSUE

>When you are counting the cost of putting a person into space, you can not
>count the costs that would be incured anyway.  For example, there is a certain
>depreciation cost for the use of the SSME and SRB motors, they only last for
>just so many launches, the depreciation would be the cost to develop and build
>the engine / number of expected uses.  These costs are fixed overhead, and
>(by standard accounting practices) not included in the costs used to make the
>decision on if the person should fly or not.  Since your going to launch
>anyway, this extra person is just a leveraged benefit.

Certainly; now justify the decision to send an "ordinary citizen" in place
of an additional mission specialist (or someone else who could really do some
good in that seat), or conversely, extending the mission by the appropriate
amount based on the savings in consumables obtained by NOT sending that Nth
person.  Or the value of sending up an additional 80 kg. or so of payload.

In addition, there WILL be additional costs (beyond consumables) in sending
the "ordinary citizen" into space.  We can expect to incur the cost of
training, outfitting, etc., not to mention whatever liability coverage is
deemed appropriate (legal waivers signed by the volunteer notwithstanding).
These will not be insiginificant, and would be much better spent elsewhere as
opposed to providing a "joy ride."



Bob Myers  KC0EW   HP Graphics Tech. Div.|  Opinions expressed here are not
                   Ft. Collins, Colorado |  those of my employer or any other
{the known universe}!hplabs!hpfcla!myers |  sentient life-form on this planet.

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

Date: 9 May 89 18:57:39 GMT
From: hpfcdc!hpfcdj![e-mail]  (Bob Myers)
Subject: Re: Spaceplane mailing list--where is it?



Ditto.  If the list still exists, I'd like to be on it.

Bob Myers


Please use the following path instead of the one in the header:

[e-mail]

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

Date: 10 May 89 18:18:41 GMT
From: [e-mail]  (Bill Chiarchiaro)
Subject: Re: Does anyone know *why* the USAF did this?



This was Project West Ford conducted by the Massachusetts Institute of
Technology's Lincoln Laboratory in Lexington, MA.  The current issue
of The Lincoln Laboratory Journal (Spring 1989, Vol. 2, No. 1) has an
article by W. W. Ward and F. W. Floyd about the Lab's 30-year
involvement with space communications, and says the following about
West Ford (I paraphrase):

In August 1958, a series of high-altitude nuclear tests, known as
HARDTACK, was carried out over Johnston Island in the Pacific.  The
first of the thermonuclear explosions disrupted the ionosphere over a
vast area and interrupted many HF radio communications.  This halted
commercial trans-Pacific air transportation.  This raised the question
of how to maintain communications in the face of thermonuclear explosions
(please, no flames...).

Walter Morrow of Lincoln Laboratory (now the Director) and Harold
Meyer from TRW considered this problem during the Army's Project
Barnstable Summer Study in 1958.  They suggested that an orbiting
artificial reflector could replace the ionosphere.  Remember, the
feasibility of placing objects in orbit had just recently been
demonstrated.

Morrow and Meyer suggested a reflector comprising a pair of belts (one
circular polar and one circular equatorial) of resonant scatterers in
orbits a few thousand kilometers high.  The scatterers would be
lengths of wire (dipoles) resonant at the system's frequency of
operation.

Lincoln Laboratory proposed setting up a full-duplex link between Camp
Parks, CA and Westford, MA.  The orbiting dipoles would resonate at
about 8 GHz, and the terminals would transmit at 7.750 GHz and 8.350
GHz.  Each dipole would be #53 AWG copper wire (0.0007-in diameter)
0.7-inch long and would weigh 40 micrograms.  A total of 480 million
dipoles (about 19 kilograms) would be distributed into circular polar
orbits at an altitude of 3,600 kilometers.  The average separation
between dipoles would be about 0.3 kilometer.  The transmitters would
use sixty-foot diameter paraboloidal dishes with 20 kilowatts to 40
kilowatts of average power.  The receivers would have maser front ends
with a system noise temperature of about 60 K.  The modulation would
be multiple-frequency-shift keying using a bandwidth of about 4 MHz.

Lincoln Laboratory realized that there would great controversy over
putting all those dipoles in orbit.  Therefore, the experiment was
designed such that solar radiation pressure would cause the dipole's
orbits to decay within a few years.

Lincoln Laboratory presented the design for Project West Ford in 1960.
It was important to address the concerns of optical and radio
astronomers who believed that the project might interfere with their
observations.  The experiment had originally been called Project
Needles, but even the more benign "West Ford" still raised a clamor on
both sides of the Iron Curtain.  Finally, presidential approval was
given for a bare-minimum test.

On October 21, 1961, the first experiment was launched piggyback on
another payload from Vandenberg AFB, CA into a circular polar orbit.
However, the dipoles did not deploy properly.  A second launch was
carried off on May 8, 1963 and was more successful.  The dipole belt
formed over a period of 40 days with an estimated density of 5 dipoles
per cubic kilometer.  In the early stages of the experiment,
communications at up to 20,000 bits/second were achieved.  By early
1966, essentially all of the dipoles had decayed.  By that time,
active communications satellites were a reality, and no more West Ford
experiments were conducted.


Other References:

    "Project West Ford Issue," Proc. IEEE 52, 449-606 (1964).

    "Project West Ford" in Compendium of Communication and Broadcast
        Satellites - 1958 to 1980 (IEEE, New York, 1981), pp. 299-302.

    D. H. Martin, "West Ford," in Communication Satellites 1958-1988
        (Aerospace Corporation, El Segundo, CA, 1988), pp. 8-9.

    P. Beckmann, Eco-Hysterics and the Technophobes (Golem Press, Boulder,
        CO, 1973), pp. 91-92

    I. I. Shapiro, "Last of the West Ford Dipoles," Science 154,
        1445 (1966).



Bill Chiarchiaro
MIT Lincoln Laboratory

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

Date: 10 May 89 17:30:47 GMT
From: tektronix!tekgen!tekigm2![e-mail]  (Timothy D Margeson)
Subject: Re: Does anyone know *why* the USAF did this?

Well,

One reason could be a third stage explosion :-(

But then, maybe they were afraid of the repeaters that the amatuers had
been hearing?


--
Tim Margeson [phone]
PO Box 3500  d/s C1-022                          @@   'Who said that?'
Vancouver, WA. 98668
e-mail replies to: [e-mail]

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

End of SPACE Digest V9 #429
*******************