Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V16_1/V16NO130.TXT

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Date: Mon,  8 Feb 93 07:18:37
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V16 #130
To: Space Digest Readers
Precedence: bulk


Space Digest                Mon,  8 Feb 93       Volume 16 : Issue 130

Today's Topics:
                              DC reentry
                           galileo update?
                  Getting people into Space Program!
                               HELP!!!
                        Help on catching this
                  Real work/Research/Jobs Priorities
                       Remotr Control in Space
                           Retaining Goldin
                  Russian Solar Sail/Media Attention
                 So what's happened to Henry Spencer?
                 Space Grown Semiconductors (2 msgs)
                 Supporting private space activities
                         Temperature of space
                           well.. (2 msgs)

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

Date: Thu, 4 Feb 1993 01:16:50 GMT
From: Henry Spencer <[e-mail]>
Subject: DC reentry
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Pat) writes:
>... the nose first trajectory conserves
>fuel, which seems to be the current tight spot in DC-Y.  if they
>still have a 10,000 lb margin after construction, then maybe
>they will skip the flip over.

Unlikely... if only because the flip is, to some extent, McDonnell-Douglas
technology that they can claim proprietary rights to.  (There have been
allegations that this is the real reason why the DC design is set up
for nose-first reentry -- because base-first with an aerospike offers
McDD nothing to call its own.)
--
"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
       -Gene Cernan, the Moon, Dec 1972 |  [e-mail]  utzoo!henry

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

Date: 3 Feb 93 19:02:01 EST
From: richard attenborough <[e-mail]>
Subject: galileo update?
Newsgroups: sci.space

RB>In article <1993Jan27.133908.16401#prime.mdata.fi>, [e-mail] (Jarno Kokko) writes...
RB>>Have people thought about combining hammering with the orbit insertion?
RB>>I think hammering when whole spacecraft is vibrating due to motor
RB>>firing would shake loose about anything :-) .. Or is it impossible
RB>>due to some minor technical detail?
RB>
RB>I don't think that would be a wise thing to do.  The motor firing has be
RB>done at a precise time with the spacecraft in the proper attitude.  If the
RB>hammering was done during the motor firing, and the antenna was to pop
RB>open, it could change the spacecraft attitude enough to really mess up the
RB>orbit insertion.  Besides, the spacecraft will very busy as it is during
RB>the orbit insertion, collecting the probe data, performing a 1000 km Io flyby
RB>and collecting science data on Jupiter.

Some time ago, Ron, you mentioned that the release of the atmosphere probe might
provide a nice "kick" to the system, releasing the ribs. Has any further study
of this possibility been done?


-Richard Attenborough-
Canada Remote Systems - Toronto,Ontario,Canada,North America,Earth........
or
Durham Board of Education BBS  (416)-666-4896   V.32bis
Fidonet 1:229/116 - Whitby,Ontario,Canada ....(you get the picture &->)


 * KingQWK 1.05 * That was Zen, this is Tao...
--
Canada Remote Systems  - Toronto, Ontario
World's Largest PCBOARD System - 416-629-7000/629-7044

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

Date: Wed, 3 Feb 1993 23:28:51 GMT
From: [e-mail]
Subject: Getting people into Space Program!
Newsgroups: sci.space

It seems that we are putting more in to our Space Program more than is
necesary..

Why can't we put some "common people" into orbit.. Why must it be PHds and
such. It sure would get more voters involved, after all why must I as a voter
spend money on a project for the direct benefit for some technocrat? Why not
have a national lottery for a one time position on the Shuttle or some other
mission into space.. Common people do not get excited about abstract things,
but get excited about tangible things.. If I was working for a NASA contractor,
I might get excited more about space. But if Im a autoworker, what does space
benefit me/and my job, none directly...

We need to get the space program down to the common person so that they can
understand where it is going and what benefits there is to it..

==
Michael Adams, [e-mail] -- I'm not high, just jacked

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

Date: 4 Feb 1993 00:00:56 GMT
From: Jeff Bytof <[e-mail]>
Subject: HELP!!!
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>From: [e-mail]

>Hey, does anyone know the rest mass of the universe and its radius? I need to
>check out a theory.
>--Ray Cote

estimate for mass of universe = 1 solar mass * 10^11 stars in galaxy *
                                10^11 galaxies = 10^22 solar masses

estimate for radius of universe = 10^10 light years

-rabjab

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

Date: Thu, 4 Feb 1993 03:29:18 GMT
From: Bruce Dunn <[e-mail]>
Subject: Help on catching this
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Rajesh Batra)
writes:

> Hi,
>
> Here's a problem that I'm just plain stuck on, see if you can help.
>
> Scenerio:  You're on the moon, a 1700 m/s container (containing ice)
which
> weighs approximately 120 kg is hurled at you. How do you catch it such
> that you can salvage the ice? You have free reign over the container-
> hence the size/material.

Do a "resal hcnual"  -- laser launch backwards :-)  Vaporize a portion of the
incoming ice with a laser, creating a thrust which deaccelerates the payload.
This is trivial compared with laser launching from the earth to low earth
orbit.  Only a fraction of the delta V is needed, and there is no atmosphere
to screw up the beam.  You may have to put the laser on a high hill however
to overcome the problem of the short distance to the lunar horizon.

--
Bruce Dunn    Vancouver, Canada   [e-mail]

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

Date: 3 Feb 93 23:19:41 GMT
From: [e-mail]
Subject: Real work/Research/Jobs Priorities
Newsgroups: sci.space

Interesting thought, are we working on a space program for "real work",
"Research" or for "jobs"... We must decide what our priorities are..

==
Michael Adams alias Ghost Wheel/Morgoth [e-mail]

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

Date: 3 Feb 93 23:12:51 GMT
From: [e-mail]
Subject: Remotr Control in Space
Newsgroups: sci.space

I might have missed something. Is there a project in hand to start doing remote
control experiments in space..

Namely to see if/how a future mission to Mars and whereever can remotely
control slave units.. Such as like if Mir was remotely controlling Znamya
versus having the ground base doing it..

==
Michael Adams, [e-mail] -- I'm not high, just jacked

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

Date: Thu, 4 Feb 1993 01:11:23 GMT
From: Henry Spencer <[e-mail]>
Subject: Retaining Goldin
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>As someone who seems to have come in on this thread in the middle of the
>discussion, could someone please explain to me what is wrong with replacing
>Administrator Goldin with someone of President-elect Clinton's choosing?

Goldin is doing something extremely rare for a man in such a bureaucratic
position:  he is making serious noises about reform, and even starting to
act on them.  Given how badly NASA needs reforming, replacing him with a
political hack like Bill Nelson would be an awful mistake.

Could you please explain to us why Goldin *needs* replacing?

He has credible technical background, credible management background, and
real interest in the job -- that alone is a rare combination -- and the
only thing anyone can find against him seems to be that he was appointed
to it by the wrong man.  Oh yes, and that he's upsetting some applecarts
that some fat contractors would rather stayed upright.

Goldin is, by the way, a Democrat.
--
"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
       -Gene Cernan, the Moon, Dec 1972 |  [e-mail]  utzoo!henry

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

Date: 3 Feb 93 23:08:45 GMT
From: [e-mail]
Subject: Russian Solar Sail/Media Attention
Newsgroups: sci.space

If the Russian Zemsya project is a "solar sail' then why does CNN says its a
mirror. The "lighting the arctic" line is or looks like lunacy to many people,
why not say what it is also.. Yes a mirror but also a Soalr Sail design
project.. and go into what a solar sail is.. One of the problems I see with the
Space Program for the US and the world, is the way the media portrays the space
programs..
==
Michael Adams, [e-mail] -- I'm not high, just jacked

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

Date: Thu, 4 Feb 1993 00:55:47 GMT
From: Paul Dietz <[e-mail]>
Subject: So what's happened to Henry Spencer?
Newsgroups: sci.space

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

> history of his single-stage-to-orbit concepts, and Mitchell Burnside
> Clapp tell you why kerosene and hydrogen peroxide is a better fuel
> combination for an SSTO than LOX/LH2?


I'd like to here more about that.  I assume the much higher density
(5-6 times?) of the kerosene/peroxide combination more than
compensates for the lower Isp, so that smaller and lighter tanks can
be used (and that having room-temperature storable propellants makes
the tanks easier to build and pressurize.)  But do you need more or
larger engines to get enough thrust, for a given size payload,
and can peroxide be pumped safely?

    Paul F. Dietz
    [e-mail]

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

Date: 3 Feb 93 18:35:18
From: Steinn Sigurdsson <[e-mail]>
Subject: Space Grown Semiconductors
Newsgroups: sci.space

 See Nature, _360_ 293-294 26 Nov 1992 for a
 summary review + references

|  Steinn Sigurdsson    |I saw two shooting stars last night        |
|  Lick Observatory    |I wished on them but they were only satellites    |
| [e-mail] |Is it wrong to wish on space hardware?        |
| "standard disclaimer"    |I wish, I wish, I wish you'd care - B.B. 1983    |

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

Date: Thu, 4 Feb 1993 04:10:51 GMT
From: [e-mail]
Subject: Space Grown Semiconductors
Newsgroups: sci.space,sci.materials

In article <[e-mail]>,
[e-mail] (Steinn Sigurdsson) writes:
[refering to space grown semiconductors]
>  See Nature, _360_ 293-294 26 Nov 1992 for a summary review + references

OK, I tried that and discovered what I suspect most others will.  The
Nov 92 issues are currently "at the bindry" for binding.  Lovely.
I can't get anything that was published between July 92 and Dec 92
it would seem.

So, Steinn, if you have a spare few minutes might you post a brief
review of what the Nature article had to say?

-Bill Gawne,  Space Telescope Science Institute

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

Date: Thu, 4 Feb 1993 01:51:22 GMT
From: Henry Spencer <[e-mail]>
Subject: Supporting private space activities
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Brian Stuart Thorn) writes:
>>...the only really technical reasons for Florida (the weather is lousy).
>
>     Don't blame Florida because NASA chose to launch Challenger on
>     the coldest day of the year. Don't blame Florida because NASA
>     launched at Atlas-Centaur into a thunderhead (ignoring the
>     near disaster of Apollo 12). Florida weather is no worse than
>     anywhere else...

The problem with Florida weather is not that it's worse than anywhere
else -- although you can make a case for this, it's not an accident that
KSC gets used by people doing lightning research -- but that it is very
hard to predict very far in advance.  The advantage of landing the shuttle
at Edwards is not that Edwards's weather is better (although it is) but
that an Edwards weather prediction is fairly reliable.  KSC not only gets
lots of thunderstorms, it gets lot of *surprise* thunderstorms, including
some that go from "chance of a thunderstorm today" to "major thunderstorm"
in the time from de-orbit burn to landing.

Ever wondered why they always roll the shuttle out to the pad in the wee
small hours of the morning?  It's because the chances of a surprise
thunderstorm are lowest then.  For the Saturn V this didn't matter,
because it had an umbilical tower on the mobile pad to carry a lightning
rod, but that tower got removed for the shuttle program.  The orbiter
has no lightning protection between the VAB and the pad, so they worry
about the weather during a rollout.  (By contrast, the first Saturn V
rolled out to the pad in weather so bad that they had to stop for 20
minutes or so because the visibility was too poor for safe driving.)
--
"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
       -Gene Cernan, the Moon, Dec 1972 |  [e-mail]  utzoo!henry

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

Date: Thu, 4 Feb 1993 01:32:33 GMT
From: Henry Spencer <[e-mail]>
Subject: Temperature of space
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Tom) writes:
>-Second thing that I've been thinking about...  What's the average
>-temperature of space (just "empty" space, not including planets, etc)?
>
>For purposes of radiating heat into space, it is treated as a 3K sink,
>since that's the temperature of the microwave background radiation.

A common misconception.  Yes, that is the temperature of the microwave
background, but there are also things like stars, the zodiacal light,
etc. that are brighter than the background.  The average temperature
of "black" sky at roughly Earth's distance from the Sun is something
like 25K, not 3K.

>I don't know if the temerature of interstellar (or intrplanetary)
>gas adds a significant amount.  Presumably, since it's been there
>for a really long time, it has already reached equilibrium with the
>background.

Not really.  Interplanetary gas is the solar wind, expelled relatively
recently from the Sun's atmosphere (if you want to be technical, it
*is* the Sun's atmosphere), and by no means at equilibrium with the
dark-sky background; in fact it's very hot.  Even interstellar gas
is more dynamic than you might think, and in fact the solar system
is thought to be within an unusually thin, unusually hot bubble of
interstellar gas thrown off by a recent nearby supernova.  (We know
the average properties of interstellar gas fairly well from long-range
observations, but if the nearby gas wasn't thin and hot, the
Extreme UltraViolet Explorer would be nearly blind because of absorption
by cool hydrogen... and it's not.)
--
"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
       -Gene Cernan, the Moon, Dec 1972 |  [e-mail]  utzoo!henry

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

Date: 3 Feb 1993 16:47 PST
From: "FRED W. BACH" <[e-mail]>
Subject: Well..
Newsgroups: sci.space,sci.misc,rec.arts.startrek.tech

In article <[e-mail]>, [e-mail] (Otto Maddox) writes...
#     How long would it take a ship traveling at Warp 1 to get to a
#planet that is 60 light years away?
#
#     I have a an answer in my head but I wanna see if I am doing this
#thing
#right.
#
#
#Otto Maddox
#[ [e-mail] ] [ [e-mail] ]

  If WARP 1 is the speed of light, then in one year (by outside observer
 measurements) the ship travels 1 light-year.  It would take the space
 ship 60 years to travel 60 light-years at warp 1.

 Fred W. Bach ,    Operations Group        |  Internet: [e-mail]
 TRIUMF (TRI-University Meson Facility)    |  Voice:  604-222-1047 loc 327/278
 4004 WESBROOK MALL, UBC CAMPUS            |  FAX:    [phone]
 University of British Columbia, Vancouver, B.C., CANADA   V6T 2A3

 These are my opinions, which should ONLY make you read, think, and question.
 They do NOT necessarily reflect the views of my employer or fellow workers.

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

Date: 3 Feb 93 23:43:01 EST
From: mike knox <[e-mail]>
Subject: well..
Newsgroups: sci.space


In Message-ID: <[e-mail]>,
[e-mail] (Otto Maddox) writes:

>     How long would it take a ship traveling at Warp 1 to get to a
>planet that is 60 light years away?

Since "warp" is a science fiction term from Star Trek, the answer has to
be given in those terms. In Star Trek, Warp 1 is defined as 1.24 x C
and goes all the way up to the theoretical maximum of Warp 10 which
is an incredible 523,171.18 x C. Star Trek also assumes a "relativistic
time dilation" of 64.6% which remains constant inside of the warp field
effect regardless of superluminal speed.

Therefore, the answer to your question is: (60 / 1.24) x 0.646 = 48 years.

(At Warp 5 it would take only about 5 1/2 days.)

 ---------------------------------------------------------------------------
    Mike Knox                  |     Fido: 1:229/15
    Brampton, Ontario          | Internet: [e-mail]
    CANADA                     | RelayNet: ->CRS  (Public Key: 22319)
 ---------------------------------------------------------------------------
---
  DeLuxe/386 1.25 #4782
--
Canada Remote Systems  - Toronto, Ontario
World's Largest PCBOARD System - 416-629-7000/629-7044

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


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From: richard attenborough <[e-mail]>
Subject: biosphere 2 oxygen
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Taber,
  RE: Oxygen levels dropping. Have you considered the possibility of fungal
growths taking place? These growths MIGHT bind up Oxygen in their mass. If the
original soil was sterilized then the fungii would have an open environment for
breeding. They would spread throughout the soil.

     This is probably NOT what is happening, but felt it couldn't hurt to
suggest it.

-Richard Attenborough-
Canada Remote Systems - Toronto,Ontario,Canada,North America,Earth........
or
Durham Board of Education BBS  (416)-666-4896   V.32bis
Fidonet 1:229/116 - Whitby,Ontario,Canada ....(you get the picture &->)


 * KingQWK 1.05 * If we don't succeed, we run the risk of failure
--
Canada Remote Systems  - Toronto, Ontario
World's Largest PCBOARD System - 416-629-7000/629-7044

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

End of Space Digest Volume 16 : Issue 130
------------------------------