karn@mouton.UUCP (10/08/84)
**** UoSAT Bulletin-95 5th October 1984 ****
UoSAT Spacecraft Control Centre, University of Surrey
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* UoSAT-OSCAR-9's Third Birthday *
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UO-9 was launched at 11:27 gmt on 6th October 1981 from
Vandenberg AFB, California into a 554 km sun-synchronous, polar
earth orbit by NASA DELTA-2130.
A great deal has happened since that day, both on the
spacecraft and on the ground. UO-9 took a little while to
'tame' - the difficult command links caused the commissioning
phase to stretch longer than anticipated and gave rise to the
well-remembered months of 'steady tone' whilst UoS and SRI
fought to regain use of the spacecraft. Those months (5) were
put to good use upgrading the ground station and, following the
successful recovery of the spacecraft, great strides were made
with the activation of the on-board experiments and
particularly navigation and attitude control. The complex and
difficult despin and attitude manoeuvres culminated in
temporary gravity-gradient stabilisation, however the
magnetometer cables on the boom became tangled during
deployment and the boom had to be retracted. The spacecraft
was then spin stabilised and the remaining experiments
activated. A weekly schedule of daily experiments have been
executed for the last two years including a weekly news
Bulletin Service; CCD image data; Radiation Experiment data,
computer-generated telemetry, DIGITALKER and whole-orbit
telemetry surveys. The Bulletin service has been especially
successful for maintaining the user community in close contact
with spacecraft operations; future mission proposals and more
general space news. The DIGITALKER experiment has had a
profound impact in schools and colleges worldwide due to its
vivid demonstration of low-cost, simple satellite
groundstations. The CCD camera has not yielded the hoped-for
image quality, but regular image dumps have stimulated interest
in image processing and acted as a development tool for the
UO-11 CCD Experiment. The best image thus far was received
this week!
UoSAT-1 has not exhibited any measurable degradation since the
failure of the secondary computer memory devices in the summer
of 1982 and the rate of decay of the orbit has been much less
pronounced than was anticipated - giving rise to an extended
orbital lifetime of, perhaps, another two years?
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* *
* H A P P Y B I R T H D A Y U O S A T - 1 *
* *
* OCTOBER 6 1984 *
* *
* from the UoSAT Team and the many *
* experimenters worldwide *
* *
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The UoSAT Team at Surrey would like to take this opportunity to
thank the many experimenters for their participation, support
and patience (!) during the mission thus far and we look
forward to more exciting projects.
** GENERAL NEWS **
** AMPTE-UKS Spacecraft Update **
The three Active Magnetospheric Particle Tracer Expt. (AMPTE)
spacecraft launched successfully by NASA DELTA from Cape
Canaveral on Thursday 16th August are reported to be
functioning well. UoSAT contributed some signal processing
modules to the UK satellite. Lithium releases have been
successfully completed on Sept 11 and 20th and the major barium
release of 10E25 ions is currently scheduled for Christmas day
1984. This release should give rise to a spectacular
artificial 'comet' visible to the naked eye from the ground.
Some experiments have been scheduled with UO-11 - more later in
the Bulletin.
** NOAA-9 **
The launch of NOAA-F (9) has been set for the 12th of November.
** UoSAT-Oscar-9 Schedule **
This weeks schedule is as follows:
Friday - load Bulletin
Saturday - Bulletin/DIGITALKER/1200 bps telemetry
Sunday - Bulletin/DIGITALKER/1200 bps telemetry
Monday - Bulletin/DIGITALKER/1200 bps telemetry
Tuesday - CCD Camera - next week Radiation data
Wednesday - Whole orbit telemetry survey
Thursday - Computer check-summed telemetry
The 21 MHz Beacon will be in use this week.
* CCD Image!! *
A routine CCD image taken last Wednesday afternoon contained a
close-up view of northern Italy with both coastlines quite
clearly defined - the best yet! Does anyone else have hard
copy of this image data? As this image was more interesting
than usual, it will be repeated next Wednesday (10th) instead
of Radiation data.
** UoSAT-Oscar-11 Operations **
* 9600 bps data was received successfully for the first time
from the UO-11 435 MHz downlink at UoS today (Friday) - work
continues!
* The real-time clock in the standard telemetry frame on UO-11
was reset to GMT (within 4 secs) on orbit 3077 (Friday 28th) to
facilitate the data-logging of telemetry. The clock was reset
using the spacecraft on-board computer feeding time information
to the telemetry system. Sorry it has taken us so long to get
around to this task!
* Particle/Wave Experiments - UO-11 and the AMPTE spacecraft
will be in conjunction for a couple of weeks at the end of
October allowing the simultaneous measurement of P/W
interactions with UO-11 and UKS. Preliminary tests will be
carried out on Monday 081084 to evaluate the P/W experiment in
preparation for this experiment. These conjunctions occur only
once every six months so we must get going! More details will
be given soon.
* No CCD images were taken this week as work continues on
preparing for the 9600 bps downlink and carrying out DCE rf
tests from UoS.
* The Particle/Wave experiment channel plate control counter
has been checked prior to testing of the Electron Spectrometer
next week. A meeting with AMPTE experimeters from the
Rutherford Appleton Labs. took place at UoS today (Friday) to
discuss the operation of the P/Wave experiment on UO-11.
A daily account of UO-11 operations follows:
DAY ORBIT CHANNELS RESET TIME
*** ***** ******** **********
Friday 3082 1,2,3,52 18:09:55
(Telemetry rate set to 300 bps for longer survey!)
(six orbits stored at lower sample rate)
Saturday Six orbit survey dump
Sunday 3108 1,2,3,52 13:05:10
Monday 3120 1,2,3,52 08:50:20
3121
3122 435 MHz downlink afsk test
ODATA dump
(OBC told to change d/link from ODATA to TLM after 8.5hrs)
Tuesday 3136 1,2,3,52 10:02:39
(OBC told to change d/link from ODATA to TLM after 9.5hrs)
Wednesday 3047 despin to Zspin~4.5 min.
3151 DCE encoder checkout for LSK
3152 1,2,3,52 13:18:22
(OBC told to change d/link from ODATA to TLM after 8.5hrs)
Thursday 3164 DCE rf tests using VHF up & UHF down
3165 ditto
3166 1,2,3,52 12:16:40
(OBC told to change d/link from ODATA to TLM after 8.5hrs)
Friday 3179 set up 9600 bps test data
3180 435 MHs beacon 9600 bps psk
nrzi data test (5 mins)
** Thanks for Reports & Questionnaire Returns **
N6CSI, ZL1GGZ, ZL1PK, ZL1BHX, ZL1UJT, ZL1MO, JE3MXU, F6BVP,
G6AAL, WB9ANQ
This week: W7AVE, JA2WO,
** Messages ** W7AVE DE G3YJO - thanks for the letter,
intrigued by your method of decoding 1200 bps Bulletin using
300 bps system! Thanks for the donation too!