Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V11_1/V11_144.TXT

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Subject: SPACE Digest V11 #144

SPACE Digest                                     Volume 11 : Issue 144

Today's Topics:
            Re: Space Probe Communications
            Re: Artificial Gravity
           Re: Solar System Questions from a Novice
         Re: Sci. Am. Lunar Telescope Article
            Re: Artificial Gravity
              Treasure Hunt for capsules
           Re: Artificial Gravity rephrased
       Re: United Space Federation (International organization)
         Re: SR-71 Record Flight Information
            Subscription to AW&ST in UK ?
             Re: SR-71:  LA to DC
----------------------------------------------------------------------

Date: 12 Mar 90 17:34:58 GMT
From: cs.utexas.edu!jarvis.csri.toronto.edu!helios.physics.utoronto.ca!ists!yunexus!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Space Probe Communications

In article <[e-mail]> [e-mail] (Chuck Rothauser) writes:
>The bit error probability was given as 1/10000....... is this reasonable?
>Seems to me that there is a lot of 'noise' out there, resulting in many
>requests for retransmission of data frames.  Perhaps higher power trans-
>mitterrs, lower temperature receivers, and larger antennas overcome the
>requirement to retransmit many data frames?

Mostly, error-correcting codes are used.  When propagation delays are
measured in minutes or hours, you do *not* want to have to retransmit
messed-up packets much.  One in 10000 is probably reasonable as raw error
rate, given Earthside facilities along the lines of DSN (good receivers,
powerful transmitters, *big* antennas), but you'll definitely want to
use a good error-correcting code on top of that to largely eliminate
retransmissions.
--
MSDOS, abbrev:  Maybe SomeDay |     Henry Spencer at U of Toronto Zoology
an Operating System.          | uunet!attcan!utzoo!henry [e-mail]

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

Date: 12 Mar 90 21:59:19 GMT
From: bfmny0![e-mail]  (Tom Neff)
Subject: Re: Artificial Gravity

In article <[e-mail]> [e-mail] (Eric Pepke) writes:
>Another thing is that, while the cylinder is spinning, you wouldn't be
>able to change the direction of the ship, so you would have to stop it for
>direction changes.

This turns out not to be true.

Gyroscopic effects only occur when the delta-vee is out of the plane
of rotation!  So long as course corrections are in-plane, you can handle
it with coordinated thrusters.

So how do you change the plane of rotation?  Flywheels.

--
Annex Canada now!  We need the room,    \)      Tom Neff
    and who's going to stop us.         (\      [e-mail]

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

Date: 12 Mar 90 13:25:46 GMT
From: uhccux!munnari.oz.au!cluster![e-mail]  (James Ashton)
Subject: Re: Solar System Questions from a Novice

In article <[e-mail]> [e-mail] (Lori + 8/9) writes:
>Can someone answer a few questions about Mercury?  Its temperature is
>hundreds of degrees F on the sunny side, and (fewer) hundreds of degrees F
>below zero on the dark side.  The poster also says that it 88 days to
>rotate.  What would Mercury's climate be like if it rotated as fast
>as the earth?  How fast would it have to rotate to produce a moderate
>or life-supporting climate, at least at certain latitudes (longitudes?)?

The reason for the extreme differences in this case is that the 88 day
rotational period exactly matchs the 88 day orbital period.  Mercury
keeps one face to the Sun all the time just as the Moon keeps one face
to the Earth permanently.  This is not as unusual as it might seem as
gravitational forces acting between orbiting bodies tend to slow down
rotation until the length of the `day' matches the length of the `year'
for one or both objects.  Almost any rotation period for Mercury other
than 88 days - be it longer or shorter - would bring the nearside and
farside temperatures much closer to each other.

                        James Ashton

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

Date: 13 Mar 90 01:34:35 GMT
From: stan!marvin![e-mail]  (Tony Jackson)
Subject: Re: Sci. Am. Lunar Telescope Article

>The interesting thing about the article was the artwork. A nice
>array of telescopes deployed without disturbing the lunar soil.
>The litle moon buggy they show *is* leaving tracks, so either
>the 'scopes were placed from above (an unseen boom attachment
>for the buggy?) or the people doing the initial placement were
>nice enough to return the site to its original boot-print and
>tire-trackless condition.
>                        James Nicoll
>PS: Smilies for those that need them, of course.

If you look at the shadows, there also seems to be a rather dense
atmosphere present, judging by the amount of diffusuion.

Also, the location of the sun is, to say the least a little odd.
(Compare the shadow angles with the location of the terminator
on the Earth in the background, for example)

Tony Jackson

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

Date: 12 Mar 90 20:11:56 GMT
From: mephisto!prism!fsu!gw.scri.fsu.edu![e-mail]  (Eric Pepke)
Subject: Re: Artificial Gravity

Another thing is that, while the cylinder is spinning, you wouldn't be
able to change the direction of the ship, so you would have to stop it for
direction changes.  Sure, you could probably keep the cylinder spinning,
but you wouldn't want to have to have the extra bulk of the structure
needed to keep the ship from snapping under that much torque.  If the
cylinder's moment is small compared to the moment of the rest of the ship,
you should be able to recover most of that energy, but it probably won't
be.

Here's another idea, which I saw first in a Piers Anthony book.  When the
ship is under acceleration, you've already got artificial gravity.  When
it isn't, tumble it end over end.  Gravity in the aft part is in the same
direction as when accelerating.  In the fore part, walk on what used to be
the ceiling.  (BTW, please don't infer from this that I am a Piers Anthony
fan.)

Eric Pepke
INTERNET:[e-mail]
Supercomputer Computations Research Institute MFENET:   pepke@fsu
Florida State University                      SPAN:     scri::pepke
Tallahassee, FL 32306-4052                    BITNET:   pepke@fsu

Disclaimer: My employers seldom even LISTEN to my opinions.
Meta-disclaimer: Any society that needs disclaimers has too many lawyers.

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

Date: 12 Mar 90 16:54:10 GMT
From: zaphod.mps.ohio-state.edu!usc!elroy.jpl.nasa.gov!aero![e-mail]  (Thomas F. Smith)
Subject: Treasure Hunt for capsules

HELP!   I'm looking for the Reentry Capsules left over
from the Discover Satellite (program WS-177 or WS-117).
It started in January 1958 with a letter contract with
Lockheed [AF04(647)-181].
McDonnell Douglas got in on it somewhere.
And GE made some smaller Biomedical capsules for monkey
flight tests.
It's the program where the film capsules were captured
in mid air over the Pacific Ocean by a special aircraft
with a V shaped rig on the front.
The program split into Discover, SAMOS and MIDOS later
Any info could help.  A Federal Stock Number would be
the most help since it could be checked on the big Logistics
computer (somewhere? in Utah?).

Aparently hundreds were made and at least a hundred
were left over and could be used for small satellite
launches.
--
This space reserved.                                     Space Not Reserved.
Space Commercialization Office, Space Systems Division, Los Angeles AFB, CA.
Newsgroups: sci.space
Subject: Treasure Hunt for RVs
Expires:
References:
Sender:
Reply-To: [e-mail] (Thomas F. Smith)
Followup-To:
Distribution: usa
Organization: The Aerospace Corporation, El Segundo, CA
Keywords: DISCOVER, SAMOS and MIDOS programs.

HELP!   I'm looking for the Reentry Capsules left over
from the Discover Satellite (program WS-177 or WS-117).
It started in January 1958 with a letter contract with
Lockheed [AF04(647)-181].
McDonnell Douglas got in on it somewhere.
And GE made some smaller Biomedical capsules for monkey
flight tests.
It's the program where the film capsules were captured
in mid air over the Pacific Ocean by a special aircraft
with a V shaped rig on the front.
The program split into Discover, SAMOS and MIDOS later
Any info could help.  A Federal Stock Number would be
the most help since it could be checked on the big Logistics
computer (somewhere? in Utah?).

Aparently hundreds were made and at least a hundred
were left over and could be used for small satellite
launches.
--
This space reserved.                                     Space Not Reserved.
Space Commercialization Office, Space Systems Division, Los Angeles AFB, CA.

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

Date: 12 Mar 90 21:08:11 GMT
From: cs.utexas.edu!samsung!zaphod.mps.ohio-state.edu!mips!prls!philabs!briar.philips.com![e-mail]  (Robert Casey)
Subject: Re: Artificial Gravity rephrased

If I was in that spaceship that was in _2001_, in the spinning section, seems
that I could throw a baseball in such a way as to cancel the spin speed.  Then
the baseball would seem to take a circular path thru the spinning section at
the height from the floor where I threw it.  Then I better duck at one
rotation! :-)  Seen from outside the spinning section of the ship, the
baseball would be staying put in one spot.  So, the artifical gravity wouldn't
grab the ball.  Make sense?

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

Date: 13 Mar 90 04:03:42 GMT
From: lazlow![e-mail]  (102SMI)
Subject: Re: United Space Federation (International organization)

Hasn't anyone read this yet?  There's no discussion!  So, the article was
a bit long...  It sounds like this guy is actually going to do *something*
which is more than many organizations can say.

In article <[e-mail]>:
>
>    WHAT IS THE UNITED SPACE FEDERATION
>
>The United Space Federation (USF) is a non-military. non-govermental,
>non-profit international organization which promotes, pursues, and
>undertakes civil space projects and missions for industry, commerce, and
>science.
    [ ... ]
>Important Update:
>
>    The United Space Federation is now in the process of being accepted
>in non-goverment organization (NGO) status with the United Nations.  Also,
>at present papers are pending with the Department of State, State of New
>York, for official non-profit status.  Presently the organization is
>establishing volunteer officer detachments at universities and colleges
>around the world.  If you are interested in obtaining more information or
>have further questions about the United Space Federation then send SASE to:
>
>            Rick R. Dobson
>            Founder and First Director
>            United Space Federation
>            POB 4722
>            Ithaca, NY 14852


I posted a few months ago about an organization which I thought was
necessary, but unfortunately, other things had to have priority in my
personal life so I was unable to put the time required until now.

I'm going to offer my services and ideas, which consist of a liaizon and
information service for the space industry, government, organizations,
and individuals, to this organization so as to `get things off the ground'
sooner.

I heard about hits guy a while ago and heard that he was very serious
and very dedicated.  Considering what the second paragraph above says,
it looks like he hasn't wasted any time and is accomplishing *something*.

Sounds good.  And Henry, it looks like he is putting in more than his
one hour a week for space.  :-)

I'm not part of this organization yet, nor have I met Rick yet, but I'm
planning on contacting him this week.  Let's get some discussions going
here so I can give him some feedback.  (He has no net account yet;
thus, he can't read it for himself.)

-Daniel

>============================================================================
>
>    It is my dream to see the United Space Federation realized within
>my lifetime.  So it is my hope that others will see the importance of this
>quest for the stars and the many benfits it will have for humankind in the
>future.
>        Thank you for your time and support, Godspeed,
>            Sincerely,
>                Rick R. Dobson
>                United Space Federation

Like I said before: I'll make it to space, or I'll die trying!!!
--
Daniel Pezely <[e-mail]> (NSFnet)      728 Bent Ln, Newark, DE 19711
Comp Sci Lab, 102 Smith Hall, U of Delaware, Newark, DE 19716; 302/451-6339

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

Date: 13 Mar 90 13:02:32 GMT
From: zaphod.mps.ohio-state.edu!rpi!crdgw1!ge-dab!puma!andrew.ATL.GE.COM![e-mail]  (John F Nixon)
Subject: Re: SR-71 Record Flight Information

[e-mail] (Bruce Lowerre) writes:
>The SR-71 was
>developed to replace the U-2.  The U-2 became obsolete when the Russians
>developed a cannon ball that could be blasted high enough to shoot it down.
>The SR-71 became obsolete when satellites were developed with telescopic
>cameras good enough to photograph the license plate of a car.

But satellites cannot provide the "unexpected" coverage of the SR-71!  You
Know where a satellite is, and where it will be, all the time.  There aren't
that many in orbit (on the US side, anyway :-).  One never knows when a
quick look could be vitally important.

This issue has been argued before.  I can't believe that *some
aircraft* didn't replace the 71.  Maybe something unmanned, smaller,
with similar performance, but surely something...

----
[e-mail]                    ...steinmetz!atl.decnet!jnxion

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

Date: 12 Mar 90 12:29:56 GMT
From: mcsun!ukc!axion!vision![e-mail]  (Simon Taylor)
Subject: Subscription to AW&ST in UK ?


    Does anyone know where one can get hold of Aviation Week in the UK ?


    Thanks

    Simon


Simon Taylor
VisionWare Ltd                  UUCP    : [e-mail]
57 Cardigan Lane                BANGNET : ...!uunet!mcsun!ukc!vision!simon
Leeds                           PHONE   : [phone] Ext. 228
LS4 2LE                         FAX     : [phone]
England
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---------------- VisionWare: The Home Of DOS-UNIX-X Integration ---------------
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------------------------------

Date: 13 Mar 90 00:07:32 GMT
From: manta![e-mail]  (Michael A. Simpkins)
Subject: Re: SR-71:  LA to DC

>>Smithsonian made the trip from Los Angeles to Washington DC
>>in 68 min, 15 sec.  The target time was 64 minutes.
>Their flight path was such that they watched the sun rise and set 3 times (this
>from an interview with the pilot).  A truley awsome experience.
>
>--
--------------------------------------------------------------------------------

    I'm afraid I don't understand how this could be if they were flying
directly West to East. Were they on some kind of zig-zag course? COULD THEY
ZIG-ZAG COAST TO COAST IN ONE HOUR!  Boy what show-offs!  :-) wow.

        somebody  'xplain please.

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

End of SPACE Digest V11 #144
*******************