Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V13_1/V13_136.TXT

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Subject: SPACE Digest V13 #136

SPACE Digest                                     Volume 13 : Issue 136

Today's Topics:
              Re: Fire in Space
          Spy satellite coverage of the Gulf
              Re: Fire in Space
          Confusion regarding "Firm Fred Decisions"
              Re: SPACE Digest V13 #088
             Re: Humanity's Launch Window
                 Space Films
              Re: Fire in Space

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Date: 5 Feb 91 04:25:19 GMT
From: umich!dgsi![e-mail]  (Greg Cronau)
Organization: Cimage Corp, Ann Arbor, MI
Subject: Re: Fire in Space
References: <[e-mail]>, <[e-mail]>
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In article <[e-mail]> [e-mail] (Gary Strand) writes:
>> Dan Gookin
>
>> If figure if you lit a match, it probably would lack the familiar conical
>> shape the flame has here on earth. In fact, I think it would look like a
>> point of light or perhaps a spherical flame.
>
>  Why? What effect does gravity have on the burning particles, relative to
>  the forces they feel from the other heated particles around them? I would
>  think that since gravity plays such a small role in what a flame looks
>  like, it would look the same on the Shuttle (say) as here on earth.
>--
>Gary Strand                           There is only one success -- to be able
>Internet: [e-mail]      to spend your life in your own way.
>Voicenet: [phone]                                 - Christopher Morley

There is a reason that a match flame has a conical shape pointed upwards.
The flame heats the air. Hot air is less dense than cold air, hence an
equal volume of hot air is lighter than the surrounding cold air. This
causes the hot air to rise and the cold air to fall into the space left by
the hot air. This is what makes hot air balloons work.
    WHICH WAY IS *UP* IN ZERO-G?!?!

There is *NO WAY* that a match flame would be conical in zero-g unless
you were waving it around in your hand. The hot air *would* be less dense,
but *gravity* is what makes that less-dense air rise! A flame has just as
much chance burning with a conical shape in zero-g as a flame on earth has
of burning with the flame pointed down or sideways.

[e-mail]

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Date: 4 Feb 91 19:55:37 GMT
From: mcsun!ukc!icdoc!inmos![e-mail]  (Conor O'Neill)
Organization: INMOS Limited, Bristol, UK.
Subject: Spy satellite coverage of the Gulf
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The media is going loopy expecting satellites to be able to spot every
Iraqi soldier scratching his nose. Anyone with any sense realises
that the coverage is intermittent, and infrequent at that.
But the question is, how infrequent?

For instance,
Given that a low orbit satellite orbits in approximately 90 minutes,
one would expect that the earth has rotated too much by the time that
the satellite returns. So we have to wait 12 hours until the Gulf rotates
to the `other side' or the earth.

I realise that the real details are almost certainly classified, but I would
like to get some feel for the answers:

(_Please_ don't say "I heard on the news that...", lets try and keep this
to the documented facts. Remember that this is a "sci." newsgroup.)

1) How many US/Allied spy satellites are likely to be targetted on the Gulf?

2) How often does each one pass over a useful part of the world?

3) What sort of width can each satellite usefully 'see' as it passes?
Can it scan the whole of this width on a single pass?
(By this I mean that it may be able to look +/- 100 miles, but only scan
10 miles at a time.)

4) What sort of resolution?
Can they count buildings? (Yes, it seems)
Can they count vehicles?  (maybe?)
Can they recognise different types of vehicles?
Can they count men?
Can they see an Iraqi soldier scratching his nose?

5) Are they affected by the dark, or by cloud cover, or is much of the
sensing done in the Infra Red?

6) Can they really detect missile and airplane launches,
or is this done by AWACS?

7) A point was made that if you knew when the satellite was due, you could
simply hide under a bridge for 10 minutes. How true is this, and
are the Iraqis likely to be able to determine enough orbital information
to do this?

8) Any other information which is available about spy satellites.
---
Conor O'Neill, Software Group, INMOS Ltd., UK.
UK: [e-mail]        US: [e-mail]
"It's state-of-the-art" "But it doesn't work!" "That is the state-of-the-art".

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Date: 4 Feb 91 21:18:27 GMT
From: zaphod.mps.ohio-state.edu!unix.cis.pitt.edu!pitt!nss![e-mail]  (Paul Blase)
Organization: The NSS BBS, Pittsburgh PA [phone]
Subject: Re: Fire in Space
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 DG> I have this perverse curiosity about what fire--specifically a
 DG> flame--would look like in space.

An experiment to do just this was performed on the shuttle recently.  Has
anyone seen the results yet?

--- via Silver Xpress V2.26 [NR]
--
Paul Blase - via FidoNet node 1:129/104
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Date: 5 Feb 91 20:33:23 GMT
From: eagle![e-mail]  (Ronald E. Graham)
Organization: NASA Lewis Research Center
Subject: Confusion regarding "Firm Fred Decisions"
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Any confusion resulting from the posting "Firm Fred Decisions" I will take
the blame for.  It turns out that I had correct information, but not
comprehensive information.  Here is the skinny:

o  The SSF program is being divided into three stand-alone phases, for
   budget purposes: man-tended capability (MTC), permanently-manned
   capability (PMC), and EMCC, whatever that stands for.  The term "stand-
   alone" I think means that each phase will be funded separately, with
   the results of the first being used to determine whether/for how much
   the subsequent phases will be funded, etc.

o  Solar Dynamic and FTS have been stopped, as I stated before.

o  The 18.75 kW power capability at MTC I mentioned previously is a number
   recommended for five years after beginning-of-life (BOL).  At BOL, they
   think 37.5 kW will be achieved.

o  The truss is to be pre-integrated (PIT), saving mucho EVA during assembly.

o  Some component and acceptance testing in the Electrical Power System (EPS)
   is to be deleted.  If anybody cares, I'll get back to you on that.

o  In the six-year period from fiscal 1991-96, a program cost reduction of
   ~$6 billion is anticipated.

Posted with minimal comment by RG

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Date: Tue, 05 Feb 91 18:10:21 EST
From: Tommy Mac <[e-mail]>
Subject: Re: SPACE Digest V13 #088
In-Reply-To: Message of Thu, 31 Jan 91 07:09:00 EST from
 <space-request+%ANDREW.CMU.EDU@CARNEGIE>
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Re: Speed of Moon's Terminator

No one has probably answered you because it would take you less time
to derive the formula your self.

Some hints: -ANGULAR velocity is independent of latitude, though transverse is
             not
            -the angular velocity of the terminator is equal to the angular
             velocity of the moon with respect to the sun (i.e. 360 degrees
             per phase cycle)

Have Fun
Tommy Mac            - Stating the problem correctly is half the problem
                     - but drawing a good picture is more impressive.
Acknowledge-To: <18084TM@MSU>

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Date: 1 Feb 91 22:02:29 GMT
From: zaphod.mps.ohio-state.edu!unix.cis.pitt.edu!pitt!nss![e-mail]  (Paul Blase)
Organization: The NSS BBS, Pittsburgh PA [phone]
Subject: Re: Humanity's Launch Window
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 NS> The only thing the Japanese really have over us is efficiency --
 NS> they manage to get some things done on quite a bit smaller
 NS> budget and less time than the U.S. -- "quick is beautiful."
 NS> But some "off the beaten path" U.S.  projects (Pegasus, AMSAT)
 NS> also demonstrate this capability.  In overall aerospace and
 NS> science they are still behind the U.S.  We could learn some
 NS> things from them about manufacturing automation, though.

I refer you to the August 13 '90 issue of Aviation Week & Space Technology.
1) The Keidanren Space Activities Council, a group of 94 companies and
trade associations involved in the Japanese space development, has asked
the government to double its budget to $3 billion.

2) Since 1985 the Japanese have formed 6 new cooperative organizations
involving contractors and space agencies.

3) Two new Japanese corporations have been created to privatize large
portions of Japan's space station activities and H-2 booster operations.

4) ISAS, Japan's version of NASA, is planning to launch a $100M lunar probe
in 1995, on a home-grown M5 booster

5) The new H-2 booster is Japanese-developed

6) The Japanese have just completed construction of their new launch facility
at Tanegashima Space Center.

The key is that Japanese Industry is taking the initiative and not merely
relying upon government funding.  Maybe we're more innovative, but they
are DOING it.

--- via Silver Xpress V2.26 [NR]
--
Paul Blase - via FidoNet node 1:129/104
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Date:    Tue, 5 Feb 1991 19:04:45 EST
From: [e-mail]
Subject: Space Films
To: [e-mail]
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For those who were asking earlier about what films wer used by unmanned photo
sattelites, I asked the fellow who designed the lunar orbiter photographic
system, who was fixing some gate problems on my movie camera for me.  He
says the system they used shot SO-243 film (which looks a lot like Plus-X
aerographic film from the 1967 datasheet... 470 lines per mm resolution,
sensitivity of 3 (I think that's about 25 ASA or so).  Extended red sensitvity.
The equipment processed the film in flight using a monobath, then did a
postive transfer onto a web like the old Polaroid pack cameras, and scanned
the positive image.  I don't know why the negative wasn't scanned directly.
He also processed the Ektachrome SO.  217 film for the Gemini flights, though
he says Gemini V also shot some Anscochrome D-50, shot on a Hasselblad with
a 70mm back.  I suspect the Ekta was an EA-2 film but am not sure.

More modern spacecraft use the Shellburst Linagraph or the RAR series of
films.  Good resolution, extended red sensitivity, high contrast, and all
the other things you look for in a good aerial film are pretty much the
same requirements for spaceborne navigation.  We still shoot a lot of that
here at Langley, but from lower altitudes than LEO....
--scott

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Date: 5 Feb 91 04:12:10 GMT
From: umich!dgsi![e-mail]  (Greg Cronau)
Organization: Cimage Corp, Ann Arbor, MI
Subject: Re: Fire in Space
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In article <[e-mail]> [e-mail] (Dan Gookin) writes:
>
>I have this perverse curiosity about what fire--specifically a
>flame--would look like in space.
>
>If figure if you lit a match, it probably would lack the familiar
>conical shape the flame has here on earth. In fact, I think it would
>look like a point of light or perhaps a spherical flame.  (And
>then my mind thought "Ooops, pure oxygen atmosphere--Whoosh!)
>
>But what would fire look like in space? or actually, zero-g? Would
>there be flames? Would it be spotty and amorphous? There is no
>scientific reason behind this; just curiosity (a mind-exercise,
>if you will).
>
>dang

Well, by "space" I assume you mean "outer space" as opposed to the
space we walk around in all day. :-) What would a flame look like in
outer space? Probably not much, considering the lack of oxygen.:-)
But, a flame in a breathable atmosphere in a zero-g environment would be
interesting. Early theory said that a bubble of CO2 would just form around
it and smother it, but on the pragmatic side, the air in all space habitats
is kept in motion so that bubbles of CO2 don't form around the *people*
and smother them! It turns out that even a flame in motionless air still
tends to get some oxygen through some kind of convective/quantum effect.
It tends to smoulder at a low level surrounded by a cloud of hot gases.

[e-mail]

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End of SPACE Digest V13 #136
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