Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V13_0/V13_074.TXT

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Subject: SPACE Digest V13 #074

SPACE Digest                                      Volume 13 : Issue 74

Today's Topics:
         NASA Headline News for 01/22/91 (Forwarded)
             Re: Ultimate Weapon
                Tenth planet?
           Re: space news from Dec 17 AW&ST
              Re: Spacing Organizations
               An Atlas Story (1 of 2)
             Galileo Update #2 - 01/24/91

Administrivia:

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

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

Date: 22 Jan 91 18:38:56 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: NASA Headline News for 01/22/91 (Forwarded)


             Headline News
Internal Communications Branch (P-2) NASA Headquarters

  Tuesday, January 22, 1991    Audio Service: 202 / 755-1788

This is NASA Headline News for Tuesday, January 22, 1991

The plasma physics experiments with the Combined Release and
Radiation Effects Satellite continued over the weekend.
Sunday morning at 12:30 am, a large barium cannister
was released into the Earth's magnetosphere by the CRRES.
Of the seven planned releases scheduled for January, six have
been accomplished.  CRRES management at the Marshall Space
Flight Center is currently examining dates for the remaining
release.

  * * * * * * * * * * * * * * * * * * * * * * * * * *

In Florida, orbiter ground processing technicians continued work
on Discovery over the weekend.  Swab samples were taken
on all main engine drain lines with the result being a clean
bill of health.  Rocketdyne technicians might take another
sample on engine #3 today.  The samples were being taken to
determine whether there was possible contamination in the
main engines from hydraulic fluid.  Discovery's Ku-band
antenna has been stowed for flight.  Following crossfeed leak
checks on the orbiter's twin orbital maneuvering system pods,
workers replaced both primary and secondary seals on all the
crossfeed lines.

Activities scheduled for Discovery today include structural
checks on the wings and leak checks on the forward reaction
control system.  The rollover date for moving Discover from
the Orbiter Processing Facility to the Vehicle Assembly
Building is still under review.

Also over the weekend, work on Atlantis advanced.  Hatch
functional checks were completed, as were fuel cell coolant loop
and system inspections.  All three main engines have now
been installed.  Work on Atlantis this week will include
potable water servicing, Ku-band antenna testing, and waste
containment system inspection.

Atlantis' STS-37 stack is well on its way to completion in the
Vehicle Assembly Building.  The left-hand solid rocket booster
stack is completed.  The right-hand aft center segment has been
stacked and work is in progress on mating the forward center
segment.

Still awaiting a spot in the OPF, Columbia remains in the VAB
where technicians continue work on orbiter tile refurbishment
and replacement.  Preparations are also underway to
access the waste-water dump-line nozzle for failure
analysis.

  * * * * * * * * * * * * * * * * * * * * * * * * * *

The STS-39 pre-flight briefings get underway tomorrow at
9:30 am EST from the Johnson Space Center.  The first briefing
will be by STS-39 lead flight director Ron Dittemore.  That
briefing will be followed by a payload briefing from the
Department of Defense at 11:00 am EST.  The flight crew
briefing will be at 2:00 pm.  Michael Coats is mission
commander and Blaine Hammond, Jr. is mission pilot.
Mission specialists for the flight, now scheduled for early March,
are Guion Bluford, Richard Hieb, Charles Veach, Gregory
Harbaugh, and Donald McMonagle.  The briefings will be
carried live on NASA Select TV.


Here's the broadcast schedule for Public Affairs events on NASA
Select TV.  All times are Eastern.  **indicates a live program.

Tuesday, 1/22/91
    12:00 pm    "Education:  A NASA Commitment."
    12:40 pm    Aeronautics & Space Report #254.
    1:00 pm        "Live via Satellite.
    1:15 pm        "Delta:  America's Space Ambassador."

Wednesday, 1/23/91
    9:30 am        **STS-39 Flight Director briefing from JSC.
    11:00 am    **STS-39 DOD payload briefing from JSC.
    2:00 pm        **STS-39 crew briefing from JSC.

Thursday, 1/24/91
    11:30 am    NASA Update will be transmitted.



All events and times may change without notice.  This report is
filed daily, Monday through Friday, at 12:00 pm, EST.  It is a
service of Internal Communications Branch at NASA
Headquarters.  Contact:  CREDMOND on NASAmail or at
202/453-8425.


NASA Select TV:  Satcom F2R, Transponder 13, C-Band, 72
degrees West Longitude, Audio 6.8, Frequency 3960 MHz.

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

Date: 23 Jan 91 16:27:16 GMT
From: sdcc6!kingkong![e-mail]  (Eric Anderson)
Subject: Re: Ultimate Weapon

In article <[e-mail]> [e-mail] (Wayne Hayes) writes:
>
>To make the Earth into a black hole, you would have to
>squeeze it into a ball about the size of a grape.

A black hole of such small mass is inherently unstable, and will
generally "evaporate" (by a somewhat complex process).  The other
poster who mentioned a black hole over Siberia was referring to a
proposition that a black hole of much less mass than the Earth was
responsible for the blast.

>The largest black holes postulated, in
>the centre of some galaxies with masses of several million Suns,
>*may* just be big enough to swallow a solar system.

A black hole doesn't have to be *nearly* as large as a solar system to
swallow it, it just needs sufficient "suck"... :-)

>If a black hole the size of the solar system was coming, you'd see
>gravitational effects long before you even saw the growing disk
>of black, missing sky as it got within visual range.

Don't forget that light would bend around it, so you'd actually see
starts, but in the wrong places in the sky.

Eric Anderson, UC San Diego    [e-mail]

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

Date: Wed, 23 Jan 91 19:51:39 PST
From: fermat![e-mail] (Richard Schroeppel)
Cc: [e-mail]
Subject: Tenth planet?

We were debating the evidence for a tenth planet, based on perturbations of
the other nine.

Henry Spencer wrote:
> ...(A very careful reassessment of observations
  of the orbit of Neptune by some folks at JPL concluded that there are no
  unexplained perturbations.) ...

I countered with a long quote from the 1988 Astronomical Almanac, page L1;
I have capitalized one sentence for emphasis:
>   Fundamental ephemerides of the Sun, Moon and planets were calculated by
    a simultaneous numerical integration at the Jet Propulsion Laboratory in
    a cooperative effort with the U.S. Naval Observatory.  Optical, radar,
    laser, and spacecraft observations were analyzed to determine starting
    conditions for the numerical integration.  In order to obtain the best
    fit of the ephemerides to the observational data, some modifications to
    the IAU (1976) System of Astronomical Constants were necessary.  These
    modification of the constants are listed on page K7.

                                                          A SATISFACTORY
    EPHEMERIS FOR URANUS FOR THE 1980'S COULD BE COMPUTED ONLY BY EXCLUDING
    OBSERVATIONS MADE BEFORE 1900.

                                    This integration, designated DE200/LE200,
    is available on magnetic tape for the period 1800-2050.  Additional
    information about the new ephemerides is included in the *Supplement to
    the Astronomical Almanac for 1984.*

I commented on the quality of the old data:
> Astronomical photography was inaugurated in 1858.  It should be possible
  to remeasure the position of Uranus accurately from old photos.

Henry responded:
> The JPL work I refer to was quite recent, as I recall, enough so that it
  might not be reflected in a three-year-old book.

I've checked some additional years of the AA:  The same paragraph is present
in the all the editions I checked, for the years 1985, 86, 88, 90, and 91,
always on page L1, the explanation chapter.

So, can someone from USNO or JPL help us out?  Is the orbit of Neptune ok,
but that of Uranus damaged?  Is JPL concealing the existence of a tenth
planet?  Is general relativity wrong?  Is Pluto really a black dwarf?
Are the Uranians manipulating their orbit just to confuse us?  Was the
1991 AA printed before the Voyager Neptune flyby?  Can Henry remember his
reference?

Rich Schroeppel  [e-mail]

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

Date: 24 Jan 91 17:22:12 GMT
From: swrinde!elroy.jpl.nasa.gov!freedom![e-mail]  (David Cornutt)
Subject: Re: space news from Dec 17 AW&ST

[e-mail] ("Allen W. Sherzer") writes:


>The public will accept risk if given an accurate assessment of the risks.

I realize that this is getting way off the thread here, but IHMO this
statement is fundementally untrue.  Today's American public will accept
NO RISK WHATSOEVER, no matter how small, if it is not something that
has existed in society prior to World War II.  This is grounded in
a fundemental lack of understanding of probability.  Just look at all
of the ruckus that is raised whenever a researcher supposes that
some environmental influence (marginal magnetic fields, Teflon-coated
cookware, Coca-Cola, etc.) might just be a contributing factor to
a handful of cancer death each year.  The public cries for ban of
the offending substance are immediate and strident; only later do
people start to think about the consequences of such a ban.

There is a deep-seated mistrust of all forms of rational thinking
(and the disciplines that arise from them) in our society that,
I think, stems from fundemental educational failures.  This
especially effects the space program, which is a national symbol
of scientific and technological progress.  You can see that in
the content of this newsgroup, which seems to me to be about 75%
flames and misinformation.  People are afraid of technological
change, and the space program (anybody's space program) is sure
to be adversely affected by this.

--
David Cornutt, New Technology Inc., Huntsville, AL  [phone]
([e-mail]; some insane route applies)
"The opinions expressed herein are not necessarily those of my employer,
not necessarily mine, and probably not necessary."

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

Date: 24 Jan 91 19:23:48 GMT
From: usc!cs.utexas.edu!news-server.csri.toronto.edu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Spacing Organizations

In article <[e-mail]> [e-mail] (Tim McDaniel) writes:
>(2) Near the end of last year, I saw a report that Iraq had launched
>    something into orbit...

This was a misreporting of a rocket launch that may have been part of
a program to develop an orbital capability.
--
If the Space Shuttle was the answer,   | Henry Spencer at U of Toronto Zoology
what was the question?                 |  [e-mail]   utzoo!henry

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

Date: 24 Jan 91 00:49:59 GMT
From: sdd.hp.com!elroy.jpl.nasa.gov!zardoz.cpd.com!dhw68k!ofa123![e-mail]  (Mark Perew)
Subject: An Atlas Story (1 of 2)

The following was posted to the Unisys A Series Mail Network
back when CRRES was launched.  With the recent discussion of
pre-historic computers I thought it would be timely to cross-
post it here.

=============================================================

Reading about the Atlas-Centaur launch vehicle for the
CRRES brought to mind a long-ago experience and a
particularly interesting (at least to me) episode.

When I first came to Burroughs (Great Valley Labs) in the
late 50's I was leader of the logic design group for the
Atlas Ground Guidance Computer for the Atlas ICBM
program.  This was all highly classified stuff, and were
the days when every few months a thing would be shot up
from Cape Canaveral and hopefully splash down in the
right place in the South Atlantic.  Our system provided
the launch guidance for this.  It has been a long time,
so some of the details I recall may be inaccurate, but
the gist is right.

The process for each test flight (our part) was this:
first the Technical Director, at that time the Ramo-
Wooldridge Corp., the predecessor of TRW, would send us
the "guidance equations" and flight parameters and we
would "program" them.  Actually a big part of the
programming was scaling to preserve the significance of
the operands;  the machine only had fixed point, single
precision arithmentic instructions.  (This was partly the
state of the art, but more importantly for reliability --
we would SWEAT BLOOD to eliminate a couple of and-gates
or a flip-flop to reduce the component count.)

Then we would wire the program into re-usable program
trays (yes, hard-wired each program for each flight,
again for reliability -- *nothing* could corrupt that
code) and ship them out to RW in California, where they
put them in a test bay hooked up to a large IBM system
which simulated the flight, with variations, to test the
programming.

Then the trays were sent to Cape Canaveral (we had a big
team there), and ultimately used for the flight.  As I
recall, the cycle for each test was about 9 months to a
year and a half.

The gist of the equations was to calculate the present
predicted impact point on the earth's surface from the
radar inputs, and issue continuous steering commands, and
the engine cut-off command when the present predicted
impact point matched the target point.  (Actually there
were several; booster cut-off, booster jettison, ...
until finally sustainer engine cutoff.)  This Atlas
launch vehicle (we called it a missile) was the first
version of the one being used with Centaur for CRRES.




--
Mark Perew
Internet: [e-mail]
Compuserve: >internet:[e-mail]
--------------------------------------------------------------------------

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

Date: 25 Jan 91 00:47:57 GMT
From: swrinde!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Galileo Update #2 - 01/24/91


                          GALILEO STATUS REPORT
                            January 24, 1992

     As of noon (PST) Thursday, January 24, 1991, the Galileo spacecraft is
22,659,670 miles from the Earth and traveling at a heliocentric speed of
82,880 miles per hour; distance to the Sun is 85, 374,930 miles (0.91 AU).
Round trip light time is 4 minutes, 0 seconds.

     A command was successfully sent on January 21 to set the Command Loss
Timer to its new value of 144 hours in preparation for the LGA-2 (Low Gain
Antenna-2) to LGA-1 antenna switch on January 31.  A separate command was
also sent on January 21 to modify the system fault protection state to select
LGA-1.  Another command to reset the Command Loss Timer to 144 hours was sent,
as planned, on January 24.

     Cruise Science Memory Readouts (MROs) were successfully completed on
January 19 for the EUV (Extreme Ultraviolet Spectrometer), DDS (Dust Detector)
and MAG (Magnetometer) science instruments; MROs for the DDS and MAG were also
performed on January 21.

     Two USO (Ultra Stable Oscillator) calibration tests were successfully
completed on January 19 and 21.  These tests provide trend information to
characterize this ultra-stable downlink frequency source.

     A total of four sun acquisition activities were successfully performed;
the sun acquisitions were performed, as planned, on January 18, 20, 21 and
23 to maintain a thermally safe sun pointed attitude.  To date four sun
acquisitions out of the 17 planned in VE-12 (Venus Earth-12) have been
completed.  Following each sun acquisition activity, star buffer memory
readouts were succesfully completed.  These readouts provide valuable star
intensity information data which is being used to update the attitude control
star catalog.

     The CDS A (Command Data Subsystem) prime and extended memory was
successfully read out on January 22; no parity errors were observed with the
memory readout.  The CDS B memory readout is planned for January 30.  At the
end of the planned uplink for the CDS "A" memory readout activity, the number
of command lock change indications observed in both CDS A and B was two more
than expected (62 vs. 60).  This is second occurrence using the 70 meter
station in Australia and third occurrence overall.  The first occurence was
on September 13, 1990.  The second occurrence at the 70 meter Goldstone station
on November 7, 1990 and resulted from a CPA (Command Processor Assembly)
hardware failure.  There was no indication of any abnormal spacecraft operation
as a result of any of these indications.  The spacecraft continues to properly
receive and process all commands.  Investigation of these unexplained
indications is in process.

     The AC/DC bus imbalance measurements exhibited some minor activity.  The
AC measurement dropped about 1 DN and now reads 46.4 volts. The DC bus
measurement dropped about 20 DN and now reads 11.6 volts; the DC measurement
reduction occurred during a period of no spacecraft activity.  All other
power-related measurements and spacecraft telemetry are normal.

     The Project reviewed and approved the final profile design for the VE-14
sequence on January 22, 1990.  The VE-14 sequence controls spacecraft
activities from February 18 to April 29, 1990.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|      Ron Baalke         | [e-mail]
     | | | |  __ \ /| | | |      Jet Propulsion Lab |
  ___| | | | |__) |/  | | |___   M/S 301-355        | It's 10PM, do you know
 /___| | | |  ___/    | |/__ /|  Pasadena, CA 91109 | where your spacecraft is?
 |_____|/  |_|/       |_____|/                      | We do!

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

End of SPACE Digest V13 #074
*******************