Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V12_4/V12_449.TXT

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Subject: SPACE Digest V12 #449

SPACE Digest                                     Volume 12 : Issue 449

Today's Topics:
            When is SALUT 7 going to fall?
              Voyager Update - 10/11/90
            Re: Ulysses Update - 10/06/90
            Clyde Tombaugh lecture
            Re: Ulysses Update - 10/06/90
              N-waste sea water dilution
           Re: disposal of N-waste into sun
           Re: Frame sequential TV in space
               Orbital elements
              Magellan Update - 10/11/90
     Re: Deep Space Network use (Was: Ulysses Update - 10/06/90)
                 Space Books

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: 10 Oct 90 08:00:41 GMT
From: mcsun!unido!mpirbn![e-mail]  (Daniel Fischer)
Subject: When is SALUT 7 going to fall?

November 1990 plus or minus two months: that was the date given in SPACE NEWS
of 26 March for the reentry and crash of the old Soviet space station Salut 7.
For months I haven't heard about that: what's the latest prediction? Did the
falling solar activity give the Soviets a few more months? But even so: that
the station should be in a stable orbit again is hard to believe. Any recent
indications of a rescue mission or controlled reentry recently? As Salut has
some 20 tons mass + another module attached, it seems we might be in for
another Skylab-style adventure. Therefore it's strange so little is being
heard about it, especially in the net ("Falling Salut - why not nuke it?" :-).

                [e-mail] <> Daniel Fischer

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

Date: 11 Oct 90 22:01:20 GMT
From: usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Voyager Update - 10/11/90


                        Voyager Mission Status
                           October 11, 1990

                              Voyager 1

     The Voyager 1 spacecraft collected routine UVS (Ultraviolet Spectrometer)
data on source  HD 217675. There was a PWS (Plasma Wave ) high-rate record
frame on October 1.  On September 28, TWNC was turned off for 3-way
ranging from the 70 meter antenna in Australia to the 70 meter antenna
in Spain. On September 29 TWNC was turned back on.

     There was an tracking outage of 4 hours and 55 minutes with the 34 meter
antenna in Spain on September 29 because of heavy rain.

     On October 3 real-time commands were transmitted to lock the PRA
(Planetary Radio Astronomy) receiver; these commands were necessary due to
the incomplete PRA recovery on September 26 which left the PRA receiver local
oscillator loop unlocked.  The PRA instrument response to the real-time
commands was as predicted.


                              Voyager 2

     The Voyager 2 spacecraft collected routine UVS data on sources Markarian
509 and PKS2155-304.  On October 2, one frame of high-rate PWS was recorded.

     There was an tracking outage of 4 hours and 45 minutes with the 34 meter
antenna in Spain on September 28 because of heavy rain.


                 CONSUMABLE STATUS AS OF 10/11/90

      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       5          36.3 + 2.0         369      56
 Voyager 2       5          39.4 + 2.0         370      62

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

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

Date: 11 Oct 90 13:19:55 GMT
From: rochester!uhura.cc.rochester.edu![e-mail]  (Bill Haake)
Subject: Re: Ulysses Update - 10/06/90

In article <[e-mail]: [e-mail] (Andy Clews) writes:
:From article <[e-mail]>, by
:[e-mail] (Ron Baalke):
:> The closest Ulysses will ever
:> get to the sun in its lifetime is when it was on Earth.
:
:Shome mishtake, shurely? What about when Ulysses was in the orbiter payload
:bay in orbit around Earth? Or even after deployment as it floated gently
Not if we weren't at perihelion when it was in orbit! :-)


--

Bill Haake                      [e-mail]    (128.151.80.13)
University of Rochester         [phone]

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

Date: 11 Oct 90 13:27:11 GMT
From: bbn.com![e-mail]  (Dick Koolish)
Subject: Clyde Tombaugh lecture



Clyde Tombaugh, discoverer of Pluto, will give a lecture
at  the  Hayden  Planetarium  of  the  Boston  Museum of
Science on Thursday, October 18 at 8:00  PM.   Admission
is  $10.00  with  all  proceeds going into a scholarship
fund.  For tickets, send a check payable to  the  Museum
of Science and a self-addressed stamped envelope to:

    Tombaugh Lecture
    Hayden Planetarium
    Museum of Science
    Boston, MA 02114

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

Date: 11 Oct 90 10:49:56 GMT
From: usc!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!watserv1!maytag!watcsc![e-mail]  (Trevor Green)
Subject: Re: Ulysses Update - 10/06/90

[e-mail] (Andy Clews) writes:
>[e-mail] (Ron Baalke):
>> The closest Ulysses will ever
>> get to the sun in its lifetime is when it was on Earth.
>
>Shome mishtake, shurely? What about when Ulysses was in the orbiter payload
>bay in orbit around Earth? Or even after deployment as it floated gently
>away from Discovery, on the side of the Earth facing the sun and before its
>boosters were fired to send it off on its merry way?
>
>I mean c'mon guys, let's have some accuracy here!   :-) :-)

Okee dokee.

The closest Ulysses will have ever gotten to the sun was some time in
early January, one of the past few years, within 12 hours of Earth's
perihelion.  We are currently at least some few hundreds of thousands,
if not millions, of kilometres shy of that point currently - a deficit
which LEO is at a loss to make up.

Happy to inject some actual accuracy into the discussion, (-:

Trevor Green

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

Date: 10 Oct 90 18:00:30 GMT
From: ubc-cs!cpsc.ucalgary.ca![e-mail]  (Michael Hermann)
Subject: N-waste sea water dilution

In article <[e-mail]> [e-mail] (Alan Hepburn) writes:
>Picture this:  a supertanker modified slightly so that the nuclear
>waste starts out in the bow tank, being diluted 100:1 with sea water.
>This mix is then pumped to the next tank where it is diluted 100:1 with
>sea water.  And so on till the last tank, which is pumped into the open
>ocean.  You would be unable to detect other than background radiation
>in the resulting water.

Gee, that's such a good idea. We could even do the same thing on land.
Perhaps in the desert. Or normal garbage headed for the landfill. I'm sure
Mr. Hepburn wouldn't mind us using his local landfill site. Afterall, one
backyard is as good as another.

I hope you were joking.

|  Mike Hermann  | [e-mail] ..!uunet!ubc-cs!calgary!hermann
_Organized_ religion is like organized crime: it preys on peoples' weaknesses,
generates huge profits, and is nearly impossible to eradicate.
--
|  Mike Hermann  | [e-mail] ..!uunet!ubc-cs!calgary!hermann
_Organized_ religion is like organized crime: it preys on peoples' weaknesses,
generates huge profits, and is nearly impossible to eradicate.

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

Date: 11 Oct 90 17:58:56 GMT
From: usc!wuarchive!cs.utexas.edu!news-server.csri.toronto.edu!helios.physics.utoronto.ca!physics.utoronto.ca![e-mail]  (Christopher Neufeld)
Subject: Re: disposal of N-waste into sun

In article <[e-mail]> [e-mail] (Dave Dodson) writes:
>In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>>In article <[e-mail]> [e-mail] (james d. Del Vecchio) writes:
>>>Why would it be harder to send something to the sun than away from the sun?
>>
>>The direction is unimportant; what matters is the velocity change needed.
>>To get something into the Sun, you have to kill *all* of Earth's orbital
>>velocity (well, just about), and that's 30 km/s, a horrendous amount for
>>chemical rockets.
>
>Time for a little arithmetic here.  Let's use the following approximate
>values for these constants:
>
>Earth's Surface Escape Velocity        11 km/sec
>Earth's Orbital Velocity around Sun    30 km/sec
>
>A launch into the sun requires sqrt (11^2 + 30^2) km/sec =~ 32 km/sec.
>This is so the payload, after having climbed out of the Earth's gravity
>well, is travelling away from the Earth at 30 km/sec.  If the velocity
>vector is in the opposite direction from the Earth's velocity vector
>around the sun, the payload would fall into the sun.
>
   This is wrong. If something is fired away from the surface of the
Earth at Earth escape velocity of ~11 km/s, it will wind up pacing the
Earth in its orbit around the Sun at 30 km/s. This is regardless of the
direction in which the object is fired away from the surface. You still
need another 30 km/s to fall into the Sun. This makes a total of 41 km/s,
not 32 km/s. I don't understand why you felt you needed the Pythagorean
identity here. Recall from first-year physics classes that the "escape
velocity" is in fact a scalar, and that neglecting atmospheric effects,
any object fired in any trajectory which does not intersect the ground or
a mountain or something, will leave if fired in excess of 11 km/s.

>A launch to solar escape requires sqrt (11^2 + (30^2)/2) km/sec =~ 24 km/sec.
>This is so the payload, after climbing out of the Earth's gravity well, is
>travelling away from the Earth at 30(sqrt(2)-1) km/sec =~ 12.5 km/sec.  If
>the velocity vector is in the same direction as the Earth's, the payload would
>have solar escape velocity and depart the solar system.
>
   Again wrong, for the same reason. It takes 11 km/s + 1/sqrt(2) * 30
km/s, or roughly 23 km/s.

>Thus solar impact requires 32/24 = 4/3 as much energy as solar escape.
>
   No, roughly 7/4.

>All of these energy requirements could be reduced by using gravity assist
>flybys of various planets, but would you want to jeopardize contaminating a
>planet with radioactive debris in case of a navigation error or onboard
>failure?
>
   No, so we'd better all get out there and put motors and navigation
equipment on every asteroid in the solar system. They may not have a
very high density of radioactive material, but they weigh billions of
times more than any earthly probe would. Oh, but natural radioactivity
is harmless, isn't it?

>Dave Dodson                                     [e-mail]
>Convex Computer Corporation      Richardson, Texas      [phone]


--
 Christopher Neufeld....Just a graduate student  | "The pizza was just a
 [e-mail]    Ad astra! | detonator; I mean, if
 cneufeld@{pnet91,pro-micol}.cts.com             | it had set off the
 "Don't edit reality for the sake of simplicity" | hams...." Downtown Brown

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

Date: 9 Oct 90 23:18:34 GMT
From: swrinde!zaphod.mps.ohio-state.edu!samsung!emory!emcard!wa4mei!ke4zv![e-mail]  (Gary Coffman)
Subject: Re: Frame sequential TV in space

In article <[e-mail]> [e-mail] (Eric Pepke) writes:
>I saw some TV pictures from the Shuttle on CNN last night, and when there
>was much motion, the image left behind colored ghost images.  This leads
>me to believe that it is essentially a frame-sequential system.
>
>If so, why is such a system used?  I know that NTSC is notoriously phase
>sensitive, but surely in this digital age we don't need to be limited by
>that.  Are the reasons historical?

It's more likely that they are using old technology single tube cameras
that suffer from color lag under modest (ie: not full sun) lighting.
Newer cameras are not as bad about this, but NASA probably hasn't updated
the cameras due to the paperwork involved in rating anything for space
use on the shuttle. The newest cameras use chip pickups instead of tubes
and suffer practically no lag.

Gary

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

Date: 12 Oct 90 00:11:00 GMT
From: [e-mail]  (Smith, Lee C.)
Subject: Orbital elements

Does anyone know what happened to Kelso's orbital elements posts?
Haven't seem them in weeks.  They would be particularly useful
in helping to track Salyut 7's impending reentry.

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

Date: 11 Oct 90 17:55:25 GMT
From: usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Magellan Update - 10/11/90


                            Magellan Status Report
                              October 11, 1990

     The Magellan spacecraft has now completed 192 mapping orbits of Venus
since the start of radar mapping operations on September 15.  Good
radar data from at least 188 orbits has been received.  Six of the seven
star calibrations in the past 24 hours were successful with attitude updates
of about 6/100 of a degree.  The foreground filter rejected one star on the
unsuccessful star calibrations.  The two desaturations were nominal.

     An increasing difference has been noted between the AACS (Attitude and
Articulation Control Subsystem) commanded position of the solar panels and
the position indicated by the potentiometers.  If allowed to continue, the
Solar Array Drive Mechanism (SADM) control loss fault protection could be
triggered and a swap of the IODA (Input-Output Drive Assembly) could be
attempted.  While the cause is being investigated, a near-term fix of
disabling the SADM control loss fault protection was approved and commanded
yesterday.  The next step is to readjust the software stops, reset the
commanded position to match the actual position, and renable the SADM
control loss fault protection.  These corrections are expected to be completed
by tomorrow.

     Commands to update the RAM and ROM safing reference parameters will be
uploaded today.  Radar engineering telemetry analysis and the production of
a test image swath from orbit 553 shows that the radar sensor continue to
operate normally.

     Prodution of standard image products throught the SAR (Synthetic Aperture
Radar) processor continues.  Eleven image swaths were successfully completed
yesterday.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|
     | | | |  __ \ /| | | |      Ron Baalke         | [e-mail]
  ___| | | | |__) |/  | | |___   Jet Propulsion Lab | [e-mail]
 /___| | | |  ___/    | |/__ /|  M/S 301-355        |
 |_____|/  |_|/       |_____|/   Pasadena, CA 91109 |

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

Date: 11 Oct 90 18:33:12 GMT
From: usc!wuarchive!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!cunews!bnrgate!bwdlh131![e-mail]  (Marcus Leech)
Subject: Re: Deep Space Network use (Was: Ulysses Update - 10/06/90)

In article <[e-mail]>, [e-mail] (Jim Barnes) writes:
> In article <[e-mail]> [e-mail] (Ron Baalke) writes:
> >
> If Ulysses needs 8 hours per day of coverage, Magellan is returning radar
> images several times a day, and Galileo is doing some interesting things
> at the same time, are there enough minutes in the day?  Will we just
> ignore the Voyagers/Pioneers/etc. for a while?  How much extra bandwidth
> does the DSN have?
The **rumour** I have heard is that NASA is trying to get enough funding to
  take over the 46M dish at the Algonquin Radio Observatory as an additional
  site for DSN work.  I'm not able to verify this, so treat is as a rumour.
-----------------
Marcus Leech, 4Y11             Bell-Northern Research  |opinions expressed
[e-mail]                  P.O. Box 3511, Stn. C   |are my own, and not
[e-mail]         Ottawa, ON, CANADA      |necessarily BNRs

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

Date: 11 Oct 90 12:11:33 GMT
From: bacchus.pa.dec.com!shlump.nac.dec.com!imokay.Berkeley.EDU![e-mail]  (Doug Borsom)
Subject: Space Books


A couple months back, someone posted a note about Wernher von Braun's
book "The Mars Project."  (A great book, as the poster pointed out.)

A  follow-up posting mentioned that the book might be available from a
San Diego bookstore, Crawford-Peters Aeronautica, that specializes in
aviation and space books.

I would like to further recommend Crawford-Peters Aeronautica as
an excellent source of all kinds of space publications.

They publish a number of catalogs (they sell for a few bucks each)
of their holdings, including,

       -Aviation and Space, 1945-1962
       -Aviation and Space, 1962-1990
       -Space and Related Titles

Titles in the catalog "Space and Related Titles" include publications
from the aerospace industry that appear to be the equivalent of the
model descriptions and spec sheets you get at your local car dealer.
In a phrase, the catalog offers lots of good stuff.

I have found Crawford-Peters pleasant and honest to deal with.

                    Crawford-Peters Aeronautica
                    P.O. Box 152528
                    San Diego, CA  92115
                    [phone]

If there are specific books you're trying to find, give them a call.
For those interested in spaceflight,  the catalogs make fun browsing all
on their own.

My only connection with these folks is that of a satisfied customer.

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

End of SPACE Digest V12 #449
*******************