Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V16_9/V16NO911.TXT

Text File | 1993-08-03 | 22KB | 551 lines

Space Digest                Fri, 23 Jul 93       Volume 16 : Issue 911

Today's Topics:
             >Re: Apollo 11: For All Mankind (transcript)
     Cold Fusion and its possible uses (if it is proven to exist)
                          comsat des'n ref's
                DC-X Prophets and associated problems
                         Isogrid Info Wanted
                    Isogrid Info Wanted (Correct)
                maximum velocity for gravity assists?
                        Moon Cable/Beanstalk.
                          Perseid publicity
                      Potential Markets for DC-?
                           SETI information
                      Space Lottery! Any Ideas?
                         Von Braun Team Work

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

Date: 23 Jul 1993 05:13:10 GMT
From: Francis Vaughan <francis@.cs.adelaide.edu.au>
Subject: >Re: Apollo 11: For All Mankind (transcript)
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (gregb) writes:

|> The transcript appears to be incomplete - The "alarms" which
|> occured during the final seconds of lunar descent are missing
|> from the transcript (the guidance computer failed). Only Armstrong's
|> training averted a catastrophic crash landing into the moon. The "coded"
|> message in the transcript notified Mission Control the LEM
|> descent was off-nominal. This is why Houston says
|> "you've got a bunch of guys about to turn blue."

Nope and Nope.  You are confusing two seperate issues.

Armstrong had essentially no idea whatsoever what the alarms meant,
except that the guidance computer was reporting an internal error.
The entire success of resolving this problem was due not to any of
Armstrongs training but due to the training and skill of the person in
mission control who decided that it was OK to proceed with the landing.
Both his skill and that of his support group in a back room.
Two seperate alarms occured during powered descent.  On both occasions the
controller responsible deeemed that it was safe to proceed.
Fifteen seconds before landing another mission controller announced
that there was thirty seconds of fuel left.   This was probably the
main reason "a bunch of guys" were about to turn blue.

When the Apollo 11 crew returned to earth they all got awarded the
medal of freedom, one other person also received this medal;  the
controller who made the call.

Armstrong however should be credited with a very cool and disciplined
landing, landing the LEM in an area strewn with boulders quite some
distance from the planned landing area (due to yet to be resolved
problems with mascons purturbing orbits and flight) was very much an
expression of skill and training.  That he did it under the pressure
of fuel limits and the psycological pressure of the first landing
are a great credit to him.

The guidance controller problem did not directly endanger the
LEM, if the failure was bad, mission control would have called
an abort, in which case the descent stage would have been jettisoned
and the LEM would have acsended to orbit once again.  There was a
small window, close to the ground in which the LEM was descending
sufficiently fast, but also so close to the moon that there was
not enough time between calling an abort and reversing the descent
to avoid impacting the moon.  However the guidance computer problem
occured a long time before this window.  The guidance computer did
not fail at any stage.  If it had done so one suspects an instant
abort call would have been made.  The call made was to simply ignore
the error and proceed as normal.  The decent was in fact still
essentially "nominal" up to then.

The "coded" message was simply an internal error diagnostic from
the guidance software.  Essentially the computer ran a real time kernel
and was notifying the outside world that it was overloaded and was
missing deadlines.  The problem turned out to be a small foul up
between MIT and mission planning, the guidance software was running
a feature that kept track of the command module, however after the
feature was added, a later decision was made not to use it.  Rather
than go through the paperwork of removing the feature the programmers
(incorrectly) decided that it could be disabled by removing the input
data.  Wrong, the program simply latched onto a random data stream
and was madly trying to make sense of it, causing the computer
to miss deadlines.  A simple change of one switch position was all
that was required to fix it for the ascent.  It was the need for this
change of switch position that was lost in the changes to the configuration.


                        Francis Vaughan

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

Date: 23 Jul 93 07:12:44 GMT
From: [e-mail]
Subject: Cold Fusion and its possible uses (if it is proven to exist)
Newsgroups: sci.physics,sci.space

Wierd question time:

If "cold fusion" is possible, as some what explained in this month popular
science.

Ho wbig would a basci unit be, how much power would it put off/out, and could
it be used in a space craft? or other places that a "small" nuclear
generator/reactor would be nice to have..

Basically what I am saying, is what uses would it have?? If it was or became
possible. Room Temperature Fusion.. Interesting..

===
Ghost Wheel - [e-mail]

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

Date: Fri, 23 Jul 1993 04:42:44 GMT
From: The Big 'G' <[e-mail]>
Subject: comsat des'n ref's
Newsgroups: sci.space

I would appreciate titles of design books for geosynchrounous
tri-axially stabilized K & C band communication sateelites. Are there
any models I could purchase to get a 3-D picture of said birds?



+------------------------------------+-----------------------------+
{           Grant Koehler            : "My feet are on the         }
{   Cal Poly Aeronautical Engineer   :     ground, but my head     }
{     GE Spacecraft Controller       :     ___    is in the stars" }
{ Internet:[e-mail] :    (o o)     -Ruth Gordon   }
+------------------------------------+-ooO-(_)-Ooo-----------------+

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

Date: 22 Jul 1993 23:59 CDT
From: [e-mail]
Subject: DC-X Prophets and associated problems
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Paul Dietz) writes...
>In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>
>>> for 1/10 to 1/20 the cost of the shuttle.  The development risk would
>>> have been much lower.  It would not have been as much of a jobs
>>> program for California, though.
>>
>> Are you sure? You'd be building 8 new vehicles a year instead of
>> 3+1 one time. I'd think you'd have more jobs.
>
>
>Well, the plan for BDB was to weld together most of the vehicle near
>the launch site.  I suppose this means California jobs for polar
>orbits, but most of the work would have been in Florida.  The design
>work would have been in California, perhaps, but it was a much simpler
>vehicle with a much smaller projected development cost.
>
>    Paul F. Dietz
>    [e-mail]

I have a copy of the Sea Dragon report put together by Aerojet in 1963. The
plan was for the Newport News or simliar shipyard to put the Sea Dragon
together. It would then by towed by sea down to KSC were the payload processing
would take place. The first payload for the Sea Dragon was to be 1 million
pounds of water! Bob Truax said to me that this would be a wonderful

payload to have in orbit and could you imagine what you could do with
1 million pounds of water in LEO!

The simplicity of Sea Dragon was to be its pressure fed single engine. This
would solve all kinds of problems associated with the use of turbopump fed
engines. What was really cool and innovative is that the second stage was
to have a corrugated sheath that would fit down over the first stage. During
the powered flight of the second stage the sheath would expand in a planned
way to provide a huge nozzle for the second stage. This effecitively gave
a nozzle throat to bell housing ratio of some huge number that I forget right
now.

Quite and interesting idea. Truax is still going at it although I think he
is around 83 years old now!

Dennis, University of Alabama in Huntsville

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

Date: 23 Jul 93 01:57:52 MDT
From: [e-mail]
Subject: Isogrid Info Wanted
Newsgroups: sci.space

news




fFORWARD
quit
end



help
?


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

Date: 23 Jul 93 02:03:18 MDT
From: [e-mail]
Subject: Isogrid Info Wanted (Correct)
Newsgroups: sci.space

Does anyone have any info concerning the "Isogrid" space structure
concept developed by McDonnell Astronautics back in the 1960's?
It was used in Skylab and in the Delta rockets.

Please contact me: [e-mail]

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

Date: Fri, 23 Jul 1993 06:59:05 GMT
From: Leigh Palmer <[e-mail]>
Subject: maximum velocity for gravity assists?
Newsgroups: sci.space

In article <[e-mail]> Al Globus,
[e-mail] writes:
>Does anyone know if there is a maximinum practical velocity that can
>be achieved using Jupiter gravity assists?

The maximum gravity assist delta-vee which can be attained in a flyby of
a planet is twice the orbital speed of the planet, and that limit is more
nearly approached the faster the object is moving as it passes the
planet. The big problem you might have is this: in order to get multiple
boosts passing Jupiter you would have to traverse orbits of increasing
major axis, and these would take increasingly long times. The other limit
you would face is that as soon as you hit a deltavee which produced a
final speed greater than escape velocity (from the solar system) you
would no longer be able to get boosts. That limiting speed is*

         VMAX = ( SQRT(2) + 2 ) VORBITAL = 44.7 km/s

for Jupiter. It would be much better to use Mercury for this purpose, in
which case the limiting speed would be 163.5 km/s, perhaps more if the
last boost could be made at perihelion, and the process of multiple
boosts would take less time. Note that using this scheme your starship
would only require 8000 years after the last boost to reach Proxima
Centauri, if that star were near the ecliptic, and it is not.

Leigh

*The derivation is left as an exercise.

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

Date: Fri, 23 Jul 93 00:26:43 GMT
From: Randy <cyphyn!randy>
Subject: Moon Cable/Beanstalk.
Newsgroups: sci.space

[e-mail] (Michael J. Black) writes:
: >Actually, you will need to buy up, or at least buy off ALL the local governements
: >along the equator. In a worst-case catastrophe the cable will come down in pieces
: >the whole way round.
:
: Screw 'em.  Ever played the game Civilization?  First guy into space wins. All
: the rest of the countries can just get out of the way.
: -black

Better idea:

 Construct a rail road track that goes completly around the Earth at the
Equator...use suggestion given above to obtain right of way.

 Track to be like the kind for roller-coasters, so the car won't fall off.

 On this track will be an electric locomotive, wired so its moters are
generators....and the nessesary pantagraph so the power can be taken off
and used by those near the track. ( A German engine using 3 phase AC has
its 3 pantagraphs on the side, not on top,  so use those. )

 On top of this locomotive, you run a heavy chain to the moon , which has a
collar around it to anchor the chain to.

 The moon, orbiting Earth, will pull the chain which pulls the loco, and so
produces electric power.

 ---*

  Bonus...connect a cable car to the chain, and you have the means to run
well guided tours to the moon.


--

Randy,KA1UNW             If you get a shock while servicing your equipment
                        DON'T JUMP!  You might break an expensive tube.

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

Date: Fri, 23 Jul 1993 06:22:36 GMT
From: Leigh Palmer <[e-mail]>
Subject: Perseid publicity
Newsgroups: sci.astro,sci.space

In article <[e-mail]> Phil G. Fraering,
[e-mail] writes:
>(Funny that you use the term Yahoo. You know where it comes from?
>Do you know the alleged geographical location?)

I'm not too Swift; I can only think of two possible places: The island of
the Whynyms (the spelling of which I've forgot) near Laputa (the spelling
of which I'm not likely to forget), and the birthplace of Einstein,
somewhere 'round Hobart, and I'm Serious about that. ;-|)

Leigh

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

Date: 23 Jul 93 06:59:08 GMT
From: [e-mail]
Subject: Potential Markets for DC-?
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Theodore F. Vaida ][) writes:
> Fill # with your prefered model (I like the DC-1 personally!)
>
> What about the commercial uses for the DC series? (including the
> original dc-x that might be usefull for sub-orbitals!)
>
>
> CREWLESS OPERATIONS:
> 1: Airborne Express (Federal Express, UPS, USPS, Percolator
> Courier...) need reliable QUICK trasportation of some INCREDIBLY urgent
> payloads (like documents from the president to the russian president
> perhaps?)
>
> 2: Breadbox science experiements that sitck out on an arm when the
> DC-1 is in orbit (speical doors needed?)
>
> 3: Landing at the 50 yard line of the superbowl (kudos to the person
> who thought this one up...)
>
> 4: Pulling tree-stumps from the yard... :O)
> >
> --
>
> ---------==============Sig file cover sheet=====================---------
>                   ->POLAR CAPS<- or [e-mail]
>       Student Konsultant Making the world safe for computing!
>
>       Pages including this page:  1
>                                 -----

Positive uses for DC-X as well as commericial uses.

FED-EX would be a good one.

Orbital or suborbital experiment is okay, but not quite what you might use it
for, unless you  had more than one oribital/suboribtal mission to accomplish.

Rescue of astronauts in a space station. Rescue/Repair/Capture of a satellite.
(basically medevac).

Space Combat (gag sorry all, thou not positive, other than in SF).
To include anti-asteroid/meteorite quick reaction team.
Also to be a ABM shield in the future. So the USSR and USA are not enemies
anymore, there is still alot of odd people who might liek to start a war..
Good use fro DC-X would be a weapons platform for bombardment of Iraq or any
other place.. Bombardment as in Ice/Dirt Chunks.. So who said Nukes were
outlawed..

Passenger flights, or for tourism..

Landing on the 50 yard lien would be interesting, but, I'd hate to underwrite
the insurance for it..

If you can extend the range of the DC-X and add soem cargo, you might be able
to go to the Moon or beyond..

Best use for DC-X is for crew roetation on a space station...

===
Ghost Wheel - [e-mail]

We must remember that DX-X is just the basic ground work and it has soem
possibilties in quite a few areas. After all its not "done" quite yet..

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

Date: Fri, 23 Jul 93 00:05:16 GMT
From: Randy <cyphyn!randy>
Subject: SETI information
Newsgroups: sci.space

[e-mail] (Russ Renaud) writes:
:
: In a previous article, [e-mail] (Remi Cabanac) says:
:
: >>Where on the Internet could one get some information
: >>re: the SETI project?  I'm looking for some basic info,
: >>as well as perhaps some technical details, such as what is
: >>the smallest discernible signal that the SETI radio telescope
: >>are capable of detecting?  How are they processing the
: >>myriad of signals they must be receiving.
: >>
: >>--
: >
: >I've just heard a lecture from Franck Drake and Billingham on the SETI project,
: >at ISU in UAH few minutes ago.  Basically, the SETI receivers are built to
: >detect the equivalent of earth emission from 5000 light years, which
: >corresponds roughly to 10-23 W/m2/Hz (I'm not sure of the units).
: >But it depends on the radio-telescope used (these data are for Arecibo).
: >The emission are processed by an MSCA able to manage 6 million channels at once.
: >Each emission is filtered with rigorous criteria such as periodicity, intensity
: >regularity, etc...
: >Until now, 38 signals are interesting and cannot be explained by radio
: >terrestrial interference (yet).  But none are periodic.
: >
: >Remi Cabanac.
:
: I would assume this would be 10^-23 Watts/metres squared/Hertz, which
: is a ratio of signal density to bandwidth.
:
: I would assume that one of the limiting factors in detecting these
: extremely weak signals would be the internal thermal noise of the
: microwave amplifiers.
:
: In conventional RF amplifiers, thermal noise is expressed as.
: Pn = KTB, where:
: Pn = Noise power in Watts
: K  = Boltzmann's constant 1.38(10^-23)
: T  = Noise temperature in degrees Kelvin
: B  = receiver bandwidth in Hertz.
:
: With GaAsFET RF amplifiers, noise temperatures of less than 50 Kelvin
: can be easily achieved even by us Amateur Radio operators.  I would
: think that the SETI microwave equipment would be capable of far lower noise
: temperatures figures, bring Pn very close to Boltzmann's constant.  I
: have no idea if Pn=KTB would be a valid equation if K is a value
: very close to 0 degrees kelvin.
:
: Can anyone shed some light on this?
:
:
: --
 For those of us trying to visualize the signal levels involved....

Assuming a plain CW transmitter, keyed slow enough to 'fit' the band-pass
of the SETI receiver, located at that distance ( 5000 Light years), how
much power would be needed for it to be heard, if the transmitter is using
a unity gain dipole, and 1400 mc?


--

Randy,KA1UNW             If you get a shock while servicing your equipment
                        DON'T JUMP!  You might break an expensive tube.

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

Date: 23 Jul 93 03:34:54 GMT
From: Bob Kirkpatrick <[e-mail]>
Subject: Space Lottery! Any Ideas?
Newsgroups: sci.space

[e-mail] writes:

> Lottery in Space and heart problems and other likely diseases/injuries for a
> Lottery Winner. Ever heard of the "Release Form".. People all over suffer fro
> more stress and such than a space launch, ever ridden in some of those nifty
> carnival rides..

> Also ever heard of the "Flight Physical" to find those nifty problems, and
> correct them, so it might add on to the cost of the launch, but you can claim
> it as an advertising expense latter on your taxes.. Or does NASA not pay taxe
> well then claim it as a operating expense or Public Relations, liek the Air
> Farce does..OR is that recruiting..

Well, you obviously don't have a grasp of the Catch-22 in this. Do all
who buy a ticket sign a waiver with each ticket they purchase? Take a
flight physical? I don't think so.

So what happens? Some poor guy who doesn't know his heart is weak pulls
the winning ticket --only to be told 'Sorry.' How can a cash award be
compensation for a trip to space? One or two of these and the idea is
history. Also, flight physicals may find things, but there isn't nec-
essarily a 'correction' for the conditions they might reveal. So,
things like this need to be worked out before the Great Idea is passed
along to any who might be able to start an implementation process.

I get the impression you read only part of my post. I pointed out that
this is what discussion of a lottery would meet with, because there isn't
a big interest in space on the part of Congress, the Senate, etc. So we
(those interested) would have to point out the advantages of doing such
a thing. Thus the tiny description on economic improvement.

I don't think a lottery can be 'written off' as advertising. Maybe it
can, but it doesn't strike me as likely. :-)

--
Bob Kirkpatrick -- Dog Ear'd Systems of Spokane, WA
I love my country. I'm just not fond of it's people and I hate the government.

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

Date: 21 Jul 93  00:00:00
From: [e-mail]
Subject: Von Braun Team Work
Newsgroups: sci.space

GW>My calculation shows the RL-10 will have an Isp about 360 at sea
GW>level;
GW>given that, a single RL-10 based demonstrator weighing 10,000 lbs at
GW>SL
GW>and 1,000 lbs at burnout should easily work.  It has a takeoff T/W of
GW>1.35
GW>and makes orbital velocity with about 300 m/s to spare, including the
GW>low-altitude thrust losses and gravity losses.
GW>
GW>I will concede "realistic"; this vehicle will have no payload.
GW>But it will make orbit.
GW>
GW>-george william herbert
GW>Retro Aerospace

Since there already is something close to your hypoethetical design - the
General Dynamics Centaur stage, perhaps a comparison with a real piece of
hardware may be illuminating. The Centaur is a 2 engine stage (2 RL-10s),
so the weight of the second engine should be considered in the comparison;
however, the Centaur weighs in at 4,000 lbs dry, not 1,000 lbs. Since the
skin of the Centaur is made of aluminum foil (for all intents and
purposes), please show me where your hypothetical design saves 3,000 lbs.
of dry mass over the Centaur.


___ WinQwk 2.0b#0

--- Maximus 2.01wb

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

End of Space Digest Volume 16 : Issue 911
------------------------------