Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V11_5/V11_551.TXT

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Subject: SPACE Digest V11 #551

SPACE Digest                                     Volume 11 : Issue 551

Today's Topics:
            E-Mail address needed
            Re: Public Perception Of Space
                Lunar SURVEYOR
         Re: Aim For The Moon - model rocket contest
         Re: Aim For The Moon - model rocket contest
              Voyager Update - 06/20/90
            Re: What makes a nebula glow??
         Re: Aim For The Moon - model rocket contest
              claiming the Moon
              Re: Saturn Rockets

Administrivia:

    Submissions to the SPACE Digest/sci.space should be mailed to
  [e-mail].  Other mail, esp. [un]subscription notices,
  should be sent to [e-mail], or, if urgent, to
             [e-mail]

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

Date: 20 Jun 90 17:53:37 GMT
From: news-server.csri.toronto.edu!utgpu!watserv1!ria!uwovax![e-mail]  (Vince Gray)
Subject: E-Mail address needed

Does anyone know the electronic mail address for a Mr. Brian McLeod, of the
Canada Centre for Remote Sensing in Ottawa, Ontario, Canada?  Please reply
to  [e-mail], as I do not normally read this newsgroup.  Thanks.

Vince Gray, Data Resources Librarian, U.W.O.

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

Date: 20 Jun 90 19:16:12 GMT
From: zaphod.mps.ohio-state.edu!usc!samsung!umich!umeecs!itivax!vax3.iti.org![e-mail]  (Allen W. Sherzer)
Subject: Re: Public Perception Of Space

In article <[e-mail]> [e-mail] (Jon C. Slenk) writes:
>Doug said that if private enterprises were the only ones to do the exploration,
>etc, things wouldn't get done too quickly (if at all), because of the pro-
>hibitive cost.

That is one factor. Another equally important one is the ways the government
gets in the way. There are a lot of laws, agreements, and policies which get
in the way. Example: Airanespace schedules customers all the same way.
Government payloads do not get special treatment. In the US however, US
government payloads always have highest priority. If they get delayed,
they just take other people's launch slots if needed. If you are paying
interest on a $250M launch, it hurts.

The government does have a role in the creation and operation of the space
infastructure (both space based and ground based). The construction of a
large space based infastructure will have the added benefit of reducing
operational costs. This will (I hope) make new markets and produce net
growth.

>I can agree with that viewpoint. There would have to be noticable benefits
>from such exploration, and they might be difficult to find, and thus
>the missions might be difficult to justify. I do not know if data on the
>outer solar system is something people would be willing to pay for if
>that was the only way they could get it.

With extensive infastructure and associated reduced costs, exploration
of the outer planets (unmanned) will be a lot cheaper. I look forward to
the day when the National Geographic Society sends off their first probe.


  Allen
-----------------------------------------------------------------------------
| Allen W. Sherzer         |          Death to all extremists!              |
|   [e-mail]            |                                                |
-----------------------------------------------------------------------------

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

Date: 20 Jun 90 08:03:25 GMT
From: bfmny0![e-mail]  (Tom Neff)
Subject: Lunar SURVEYOR

I am interested in any articles sci.space readers might have on the
SURVEYOR program of unmanned lunar soft landers 1966-68.  You are
invited to post articles here or email them to me.

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

Date: 19 Jun 90 01:54:05 GMT
From: zaphod.mps.ohio-state.edu!mips!pacbell.com!pacbell!sactoh0!unify!csusac!csuchico.edu![e-mail]  (Ralph Reid)
Subject: Re: Aim For The Moon - model rocket contest


Sounds like a great idea, but how big can a model get until it is no
longer a model?  I like the idea of just getting to the moon with
small rockets; perhaps a crash landing resulting in a small crater
would not require any radio at all (just send the rocket there by
itself?).

--
Ralph.
ARS: N6BNO
Compuserve: 72250,3521
email: [e-mail]

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

Date: 20 Jun 90 21:24:53 GMT
From: sam.cs.cmu.edu![e-mail]  (Vincent Cate)
Subject: Re: Aim For The Moon - model rocket contest


Lawrence Curcio:
>Assumptions:
>[...]
>Rocket is composed of class N clusters, because Class N engines
>have the best mass ratios
>
>Top stage is one N engine
>
>Each stage carries stages above it that total half of the mass of
>the current stage => mass ratio of each stage is 2.0
>[...]
>ENGINES REQUIRED= 6561
>MINIMUM COST IN $ 8529300   (That's $8,529,300.00)
>
>Any calculational errors? Please correct and repost.

You do NOT want the total weight of all of the above stages
to be half the current stage weight for model rockets where
the current stage case weight is significant.

You do NOT want to have your smallest stage be made from the largest
and most expensive rocket engine that you can buy.  The goal is to
end up with 1 oz way up there, not kilograms (the last case in your
design weighs 2 kg!!).  We are not after efficiency, only low cost.
If your smallest engine costs $2,000 and each larger stage costs more than
a factor of two more than the previous (your design) your total cost
will be around 2,000 times as much as if your smallest stage cost
only $1.00.   The whole point of the idea is to use small cheap motors
to send up a very very small payload!!


Some real prices from Vulcan Systems Inc [phone]:

Motor  Thrust  Length     Cost
--------------------------------
E       40 ns   3.0  in     $8
F       80 ns   4.5  in    $10
G      130 ns   6.0  in    $15
H      320 ns   7.25 in    $32.5
I      640 ns  11.25 in    $60
J     1280 ns  11.25 in   $110
K     2560 ns  22.0  in   $210


They did not give me the weights of the motors.

Imagine a multistage rocket made using one motor from each motor type.
If each motor were only 1/2 fuel (the other half case) each stage
would act like a single stage rocket with 25% of its weight as fuel.
By my calculations a single stage rocket with an Isp of 230 that is
25% fuel will get a delta-V of 1,500 MPH.  In practice all motors from
G to N are over 1/2 fuel so they will do better than this.  So it
should be possible to make a rocket with less than 14 stages (A to N)
that gets the needed delta-V.  If you launch from a balloon you could
start at 100,000 feet and avoid most of the air.  It now looks like you
could buy one motor of every type up to "N" for under $3,000.

   -- Vince


PS  Has anyone calculated what a space shuttle solid rocket booster is on
    the "model" rocket scale?  Seems like it will be something like 100 "Z"s
    but I don't have the data for the SRBs.

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

Date: 21 Jun 90 05:06:05 GMT
From: usc!zaphod.mps.ohio-state.edu!sdd.hp.com!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Voyager Update - 06/20/90


                     Voyager Mission Status Report
                            June 20, 1990

                              Voyager 1

     The Voyager 1 spacecraft continues to collect routine cruise science data.
A  Computer Command Subsystem (CCS) timing offset determination test was
performed on June 11 and one frame of high-rate Plasma Wave (PWS) data was
recorded on June 12.  High-rate Ultraviolet Spectrometer (UVS) observations
were conducted on HD 217675 (June 8) and HD 199579 (June 12 and June 14).

     On June 8 full Attitude and Articulation Control Subsystem (AACS),
Computer Command Subsystem (CCS), and Flight Data Subsystem (FDS) memory
readouts were executed by the Voyager 1 spacecraft.  No problems were
encountered during the readouts.  Manual comparison of the memory readout
addresses missed during the post CCSA refresh readout on June 7 have been
completed and indicate that the contents of these addresses are as expected.
Also on June 8, a Magnetometer Calibration (MAGCAL) was executed.  No problems
were observed with the calibration.

     On June 11 a series of four Digital Tape Recoders (DTR) Tape Positioning
tests (TAPPOSs) were executed using the DTR Maintenance (DTRMA) Block Routine
(BR9).  This was the first execution of this block routine and DTR operation
was nominal.  A CCS Timing (CCSTIM) test was also executed which indicated
that the offset between the FDS frame start and the CCS timing chain in each
processor has not changed since the previous test.

     On June 8, 12, and 14 UVS observations were executed.  Spacecraft
performance appeared to be nominal however, the downlink Signal-to-Noise
Ratio (SNR) was 1 to 2 db below the predicted values for most of the three
passes by the 70 meter antenna in Spain.  Only the first three hours of the
five hour observation on June 14 was received due to the lack of Deep Space
Network (DSN) coverage.

     On June 13 real-time commands to perform a CCS Calibration (CCSCAL) were
transmitted to the spacecraft.  CCSCAL was confirmed by CCS checksum and the
CCSCAL indicated that there has been no change, since the previous test, in
the instruction cycle timing derived from the CCS oscillator when compared
with the sequence timing derived from the FDS oscillator.


                              Voyager 2

     The Voyager 2 spacecraft also continues to collect routine cruise science
data.  The only significant real-time telemetry outage was loss of one hour
of CR-5T data during the June 14 70 meter antenna tracking pass in Goldstone,
California, due to on-antenna repairs to transmitter equipment.  (These
repairs delayed the planned Doppler drift-through activities to the extent
that no downlink coverage was available to observe their effects.)

     On June 11 calibrations of the Plasma Subsystem (PLS), MAG, and Low
Energy Charged Particles (LECP) instruments was performed.  This was the
first time that this autocal sequence has been executed with the VIM-5 FDS
program.  It was programmed to begin at an FDS "mod 60" count of "9" for
checkout purposes; the calibration execution appears to have been nominal.
However, the transition from CR-5T to UV-5A again caused problems. The PLS
and LECP status words were incorrect and erratic.  The LECP stepping motor
position was checked in the raw data and is stepping correctly.  The
engineering and temperature channels were all nominal for the Fields &
Particles (F&P) instruments and the Cosmic Ray (CRS) and MAG instrument
status words were unaffected.

     UVS high-rate data were taken on PKS2155-304 starting June 14 in the
new UV-5A data mode.  The quality of this data is unknown because
lack of the capability to look at the data in near real-time.




                  CONSUMABLE STATUS AS OF 6/20/90

    P R O P E L L A N T    S T A T U S          P O W E R

                     Consumption
             One Week    Propellant Remaining     Output     Margin
  Spacecraft  (Gm)                (Kg)            Watts      Watts

   Voyager 1    3             36.4 + 2.0          370         59
   Voyager 2    6             39.5 + 2.0          374         66

       _   _____    _
      | | |  __ \  | |       Ron Baalke           |  [e-mail]
      | | | |__) | | |       Jet Propulsion Lab   |  [e-mail]
   ___| | |  ___/  | |___    M/S 301-355          |
  |_____/ |_|      |_____|   Pasadena, CA 91109   |

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

Date: 19 Jun 90 14:03:36 GMT
From: sdd.hp.com!zaphod.mps.ohio-state.edu!samsung!xylogics!linus!helios![e-mail]  (Cookson)
Subject: Re: What makes a nebula glow??

In article <107@contel0> maxz@contel0 (Mark A. Maxwell Senior Systems Support Analyst ) writes:
>-------------------------
> I read an article in the sunday 6/17 New York Times about
> the upcomming solstice, they happened to mention in a description
> of nebula that stars deep within the nebula excite gases and debris
> which gives off the glow.  They said it was similar to the way a florescent
> light works.  Is it not that these gases are just reflecting light
> from these internal sources or is there more to it?
>
It is not.  The stars within the nebula emit radiation.  The gasses in the
nebula (mainly hydrogen, some helium, and small amounts of a bunch o' other
stuff) absorb the radiation, and hence become excited (electrons jump
to higher shells).  When the atoms de-excite (electrons return to a lower
shell) they have to radiate away the energy that bumped the electrons out
in the first place.  The way they do this is each electron emits a photon
when in makes a transition (downward that is, it absorbs one when it excites),
and thus the gases glow.  Sort of a neon sign on steroids :-).

Dean


% Dean Cookson                  $ Anyone can be taught to sculpt    %
% [e-mail]                $ Michaelangleo would have had to %
% {devax,et al..}!linus!mbunix!helios!cookson $ have been taught how not to.  %
% Disclaimer: My opinions are my own, and       $ The same is true of great   %
%       are of questionable sanity                $ programmers               %

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

Date: 21 Jun 90 04:03:38 GMT
From: mcgill-vision!clyde.concordia.ca!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Aim For The Moon - model rocket contest

In article <[e-mail]> [e-mail] (Ralph Reid) writes:
>Sounds like a great idea, but how big can a model get until it is no
>longer a model? ...

I believe the US regulations are set up so that any rocket capable of
going above 100km falls under OCST jurisdiction, i.e. it is a full-fledged
launcher requiring full paperwork.  The rules don't say "100km" for silly
reasons of interagency politics, but they set restrictions on total impulse
and the like that supposedly amount to a 100km limit in practice.

Under that there is a large gray area where OCST does not get involved,
but the FAA and explosives laws do; I don't know much about the situation
there.

To truly qualify as a model rocket, it has to pretty much stay within
the orthodox model-rocket rules and size limits.
--
As a user I'll take speed over|     Henry Spencer at U of Toronto Zoology
features any day. -A.Tanenbaum| uunet!attcan!utzoo!henry [e-mail]

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

Date: 21 Jun 90 04:29:48 GMT
From: mcgill-vision!clyde.concordia.ca!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: claiming the Moon

In article <[e-mail]> [e-mail] writes:
>A very long time ago in the 1950s, somebody advertised in the science
>fiction magazines of the day, that people could buy 1 inch square sec-
>tions of the moon for $1.00...

I've heard of this.  Those claims had zero legal status even at the time,
and the Outer Space Treaty of the early 60s rendered them completely null
and void, I believe.
--
As a user I'll take speed over|     Henry Spencer at U of Toronto Zoology
features any day. -A.Tanenbaum| uunet!attcan!utzoo!henry [e-mail]

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

Date: 21 Jun 90 04:24:25 GMT
From: mcgill-vision!clyde.concordia.ca!news-server.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Saturn Rockets

In article <[e-mail]> [e-mail] (Bob Mosley III) writes:
>1) We've seen the results of the Saturn program, but what about the progress
>on the followup, the Nova series? I remember seeing photos of Werner Von Braun
>standing beside small models of proposed Nova boosters, but these were from
>1964 or so.
>How far did development go on the Novas, and when did they officially get the
>axe?

The primary mission for Nova was direct flight to the Moon, and it died
when that mission approach did, late in 1962.  In fact, Nova really died
7 Sept 1961, when the Michoud plant was chosen as NASA's heavy assembly
facility, because a cluster of more than five F-1s wouldn't fit under
the Michoud roof with the stage on its side.  From that point on, Nova
rapidly receded into the dim post-Saturn future.  Von Braun and his crew
at Marshall had more or less written Nova off as an Apollo booster a bit
earlier, which is why they didn't object to the choice of Michoud.

At that point, Nova was still a generic term for a wide range of big-booster
concepts, and nobody had really settled on anything specific.  The closest
anybody came to a detailed post-Saturn-V design was the Saturn C-8, with
eight F-1s in the first stage, which was either an enlarged Saturn or a
junior Nova depending on your point of view.
--
As a user I'll take speed over|     Henry Spencer at U of Toronto Zoology
features any day. -A.Tanenbaum| uunet!attcan!utzoo!henry [e-mail]

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

End of SPACE Digest V11 #551
*******************