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>Xref: infoac rec.radio.amateur.misc:710 sci.space:18276
>Path: infoac!unido!fauern!ira.uka.de!sol.ctr.columbia.edu!samsung!spool.mu.edu!mips!dimacs.rutgers.edu!rutgers!ka2qhd!kd2bd
>From: kd2bd@ka2qhd.UUCP (John Magliacane)
>Newsgroups: rec.radio.amateur.misc,sci.space
>Subject: * SpaceNews  25-Mar-91 *
>Keywords: U2MIR, PACSATs, STS-37, QRM
>Message-ID: <426@ka2qhd.UUCP>
>Date: 23 Mar 91 02:03:31 GMT
>Organization: KA2QHD - OCEAN NJ
>Lines: 142


SB SPACE @ AMSAT < KD2BD $SPC0325
* SpaceNews  25-Mar-91 *

Bulletin ID: $SPC0325


                              =========
                              SpaceNews
                              =========

                         MONDAY MARCH 25, 1991

SpaceNews originates at KD2BD in Wall Township, New Jersey, USA.  It
is published every week and is made available for unlimited distribution.


* U2MIR NEWS *
==============
U2MIR Activity Patterns   by John Shalamskas, KJ9U  3/17/91

Evidently, the best times to work the cosmonauts "live" are weekends UTC,
with some leeway for Fridays and Mondays.  Currently, their work schedule
of 08:00 to 23:00 Moscow time means that they are asleep from 23:00 to
08:00 Moscow time.  Watch for passes during their wakeful hours if you
wish to have a "live" conversation.  It's quite an experience!

UTC: "Prime Time" hours are from 05:00 to 20:00 Friday - Monday

For the record, his name is pronounced "Moo'sah", and he really does
have some trouble with the English language.


* STS-37 NEWS *
===============
A Flight Readiness Review for STS-37 is scheduled for March 26 and 27.
Shuttle Amateur Radio EXperiment (SAREX) schedules have already been
made with various schools around the country.  On 05-Apr-91, several
"bridges" have been scheduled so astronauts can communicate directly
with school children using Amateur Radio.  Contacts will be made at
15:11, 18:29 and 20:20 UTC using both voice and slow-scan television
(SSTV) on this date.  Audio re-transmissions of these bridges should
be available on WA3NAN, the Amateur Radio club station at the Goddard
Space Flight Center in Greenbelt, Maryland.

[Info via N9JEL]


* PACSAT NEWS *
===============
After spending two weeks studying memory dumps, NK6K and G0/K8KA have
determined the cause of the on-board computer crash which occurred on
AO-16 March 2.  NK6K traced the crash back to an inefficient way in
which a "homebrew" PACSAT user program requested information about new
files stored on the BBS.  Because of the slow way the search for new
files was being performed and the fact that at the time of the crash there
were over 560 files stored, the file server took a lot longer to search
than normal.  After sixty seconds, a critical software timer timed out,
and as NK6K put it, "the dominoes started falling."

Now that this problem has been identified, G0/K8KA has made a change in
the PACSAT file server software so that this problem won't re-occur.
Also, new implementation notes will be published so that all writers of
PACSAT ground station user software will be aware of the change in the
PACSAT Protocol.

As of 03:00 on March 15, 1991, the BBS on AO-16 was back in operation.
Likewise, the BBS on LUSAT-OSCAR-19 (LO-19) was on-line, according to
LU7XAC.  It is believed that the LO-19 on-board computer crash was due
to the same problem, manifest in a slightly different way.  NK6K points
out that PACSAT BBS software is much more robust with each new version,
and the time between crashes is increasing.

[Info via ANS]


* INTERSTELLAR QRM *
====================
145.825 MHz has become a popular frequency for VHF radio links with OSCAR
satellites.  At the present time, 145.825 MHz is used as a downlink for
both OSCAR-11 (UoSAT-2) and OSCAR-17 (DOVE-1).  RS-14/OSCAR-21 is a close
neighbor, using 145.822 MHz for a CW telemetry beacon.  At the same time,
RS10 and RS11 use this frequency (+/- 5 KHz) for uplinks to their auto-
transponders, or "robots".

The popularity of 145.825 MHz has created some real problems!  On frequent
occasions, OSCARs 11, 17 and 21 can all be heard at once, causing severe
interference between satellites and making it impossible to copy ANY
satellite when all three come into range at once.  There have also been
occasions when RS10 or RS11's "robot" uplinks have been interfered with by
constant carrier (FM) emissions from OSCAR 11 and/or 17.  Since many OSCAR
satellites are placed in sun-synchronous orbits, they often come into range
of a given satellite groundstation at about the same time every day, and if
they all use the same beacon frequency, the severe interference problem
results.

145.825 MHz is simply getting too crowded for practical use.  Even the
short-lived BADR-1 spacecraft used this frequency as an outlet for its
telemetry beacon.  Perhaps we should look toward using the 144.300 to
144.500 MHz OSCAR subband in future amateur spacecraft.

Something to think about.... de KD2BD


* TNX QSL! *
============
A special thanks to all those who sent QSLs to SpaceNews:

KB2HMK  : Michel Zadoroznyj, Garfield, New Jersey, USA
N3IKS   : John Ford Gibson III, Philadelphia, Pennsylvania, USA
N6YGD   : Donald Bowtell, Byron, California, USA
WB9OKM  : Leland Ronzheimer, Waukegan, Illinois, USA
WT0N    : B.J. Arts, Plymouth, Minnesota, USA

...and e-mail messages:

KB2FID, N2AAM, VK2BBD, WA2N, TI3DJT, KC4UZA, SM6JNS, N9JEL


* FEEDBACK WELCOMED *
=====================
Feedback regarding SpaceNews reports may be directed to the editor using
any one of the following paths:

INTERNET : kd2bd@ka2qhd.de.com
PACKET   : KD2BD @ NN2Z.NJ.USA.NA
UUCP     : ...rutgers!ka2qhd!kd2bd

MAIL     : John A. Magliacane, KD2BD
           Electronics Technology Department
           Advanced Technology Center
           Brookdale Community College
           765 Newman Springs Road
           Lincroft, New Jersey  07738
           U.S.A.

/EX
-- 
John A. Magliacane                 FAX  : (908) 747-7107
Electronics Technology Department  AMPR : KD2BD @ NN2Z.NJ.USA.NA
Brookdale Community College        UUCP : ...!rutgers!ka2qhd!kd2bd
Lincroft, NJ  07738  USA           VOICE: (908) 842-1900 ext 607
-- 
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