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[jamsat-news:848] * SpaceNews 22-Jun-98 *

* SpaceNews 22-Jun-98 *

BID: $SPC0622


                          MONDAY JUNE 22, 1998

SpaceNews originates at KD2BD in Wall Township, New Jersey, USA.  It
is published every week and is made available for non-commercial use.

The prospects of having the Phase III-D amateur radio communications
satellite launched this year from a European Space Agency "Ariane" flight
have dropped to zero.  On 1998-Jun-15, it was announced that a dummy
satellite representative of Eutelsat's W2 spacecraft would be flown along
with ESA's Atmospheric Reentry Demonstrator (ARD) on Ariane flight 503,
now officially targeted for "Mid-October".  The Phase III-D satellite will
not be carried on flight 503, despite the numerous assurances given to AMSAT
over the past several months.

According to a recent "go-Ariane" report, when questionned as to the reasons
that had led to broken promises to AMSAT, Arianespace Chairman Jean-Marie
Luton fully explained the situation in terms of urgency.  "We had to
constitute a pairing, the ARD and another payload within the allowable
mass limits.  After the fire that damaged W1 which had been scheduled on
503, the fact that the sister craft W2 would not be ready and our inability
to find an alternative commercial passenger, we decided to have a dummy
satellite that was as dynamically representative as possible of a W series
satellite - and that without having to start all the studies from scratch
which would have pushed back the launch.  If AMSAT had been accepted, the
launch could not have taken place before the end of the year."

AMSAT was officially notified that AMSAT Phase III-D cannot fly on Ariane
flight 503 "because it would take 8 months to fullfill the necessary
studies."  AMSAT is now considering its future options for the Phase III-D
spacecraft, and does not exclude a solution to be found with Arianespace.

According to an announcement made by the FO-29 command station, bit errors
were detected again on 1998-June-08, and the on board computer was reset
1998-Jun-09.  Investigation into the bit error problem continues.

Controllers are asking that groundstations monitor channel "2A" in FO-29's
CW telemetry.  Channel 2A is the fifth item after "HI HI", and is usually
reported as "00".  Reports should be sent to: lab@jarl.or.jp.

[Info via Kazu Sakamoto, JJ1WTK]

During the period 1998-May-16 to 1998-June-14, reasonably strong signals
have been received from UoSAT-OSCAR-11's 145.826 MHz VHF-FM beacon.  The
satellite was not monitored between 1998-May-27 and 1998-June-10.  However,
there is no evidence of ground control operations, and it appears to have
been another uneventful period.

Telemetry continues to be nominal.  The battery voltage has tended to rather
low levels, averaging 13.5 volts, with one value of 13.2 volts observed.

The internal temperatures have fallen by about 2.5 C to 2.2 C and 0.6 C
for battery and telemetry electronics respectively.

A single WOD survey of channels 1, 2, 3, 61 (magnetometers) dated 1998-Mar-19
has been transmitted.  A quick plot of this WOD showed reasonable agreement
with the theoretical field, and nominal attitude.  Anyone using this survey
should note the unusual starting time of 16:00:05 UTC.

Reports of the OSCAR-11 Mode-S beacon have been received from Roger W3SZ,
Jim AF9A, Micheal OH2AVE, and Jack W9JIU.

The operating schedule remains unchanged:

        ASCII status (210 seconds)
        ASCII bulletin (60 seconds)
        BINARY SEU (30 seconds)
        ASCII TLM (90 seconds)
        ASCII WOD (120 seconds)
        ASCII bulletin (60 seconds)
        BINARY ENG (30 seconds)

The ASCII bulletin is currently a static message, detailing modes and
frequencies of all the amateur radio satellites.

There are additional status blocks after each bulletin is transmitted,
and between ASCII TLM and WOD.

The Mode-S beacon is ON, transmitting an unmodulated carrier, but telemetry
indicates that it has partially failed and delivering only half power.
This beacon is a useful test source for those testing Mode-S converters
prior to the launch of P3-D.  It is considerably weaker than DOVE, which
should be used for initial testing.  Any reports of reception on 2401 MHz
would be most welcome, and should be directed to Clive Wallis at:

The 435.025 MHz beacon is normally OFF.  However, it can sometimes be heard
when the satellite is being commanded by ground control (ie. within range of
Guildford, UK).  When the 435 MHz beacon is transmitting, the 145 MHz beacon
is normally OFF.  The data transmitted is mainly binary.

Listeners to OSCAR-11 may be interested in visiting Clive Wallis's web site.
The web site contains details of hardware required and some software for
capturing data, and decoding ASCII telemetry and WOD.  There is an archive
of raw data (mainly WOD) for analysis, which is continually being expanded
as new data is captured.  Also included are some audio files containing
examples of each type of data transmitted by OSCAR-11.  Each one plays
for about ten seconds.  There are also examples of Mode-S reception.
All the audio files are zip compressed, so that they can be played off-line.
These should help listeners identify the various types of data, and give
an indication of the signal quality required for successful decoding.

The URL is:


[Info via Clive Wallis, G3CWV]

The TMSAT-1 telemetry configuration file for DTLM is available on the UoSAT
web site at -:


In addition, up-to-date news will be posted to this page as the mission

[Info via Chris Jackson G7UPN / ZL2TPO  (HS0AM)]

The news as of 1998-Jun-18 is that SEDSAT-1 has PASSED its vibration test.
All three axes went fine.  For each axis, an up/down sine diagnostic sweep,
a body dynamics sine test, a random vibration test, and an other up/down
sine diagnositic sweep was performed.

1. All modes were at constant frequency before and after the vibration
(within a few Hz).

2. No modes had center frequencies below 65 Hz.  The lowest frequency mode
in the X and Y directions appears to have been rocking on the PAF, although
there was not enough instrumentation to prove this.  Assuming that is the
case all SEDSAT body modes are above 95 Hz.

3. In the Z vibration which was expected to maximally excite internal
components, designers could hear some distinct internal "buzz" and "hum"
sounds at particular frequencies.  However, everything passed functional
tests afterward.

4. During the functional tests two anomalies were observed.  First was
unstable current readings from the internal main bus current sensor.  This
spontaneously disappeared after some operation.  The second was reduced
brightness and contrast in the PAL images after the X shake.  It is possible
this is due to a lens iris problem.  Designers will do some analysis later
but do not plan any opening of the satellite.

5. The shock test was scheduled for 1998-Jun-19.

6. Ground handling and GSE continues to be a problem.  Designers were able
to complete all required operations, but doubts were raised about several
steps with the flight PAF that could not be fully resolved.  The differences
between the T-PAF used for vibration, the test PAF used for shock, and the
flight PAF make the issue more complicated.

A really BIG thank you to everybody who has helped get the SEDSAT-1 design
team to this point.  Special thanks to Larry Berge and Mike Henderson at
Boeing, Mike Goeser at Goddard, Christine O'Neill at JSC, Marion Thompson
at KSC, Jim Harrison at Marshall, and the whole staff of the vibration lab
at Marshall who've been putting up with abortive tests and every changing
PAFs for quite a while.

[Info via Dr. Mark W. Maier and Dennis Ray Wingo]

Comments and input for SpaceNews should be directed to the editor
(John, KD2BD) via any of the paths listed below:

WWW       : http://www.njin.net/~magliaco/
INTERNET  : kd2bd@amsat.org, magliaco@email.njin.net

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