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[aprssig] PCSAT2's First Day Operations Summary (+1)

Robert Bruninga bruninga at usna.edu
Thu Aug 4 20:41:24 UTC 2005


Postscript.  A note about PCSAT2 was posted
on a popular news group called slashdot and

"In terms of the numbers, there were about 
40,000 extra visits and over a million extra hits
in the last 18 hours..."

We have no data on our own USNA actual PCSAT2
web pages since the entire building was down
as well as our web pages, HVAC and power.
The entire USNA PCSAT2 initial operations and
checkouit was conducted on emergency power 
over 3 days on one 15 amp emergency circuit 
with one lamp, a few flashlights, radios and 7 laptops.

Many thanks to the USNA infrastructure technicians
that made sure we had the power circuit,
telephone and a wireless LAN into one laptop.

Bob Bruninga
USNA Satellite Lab


>>> Robert Bruninga 08/04/05 4:19 PM >>>
PCSAT2 Day 1 Summary:

After Deployment, PCSAT2 minimum operating commands
were established by USNA ground station on a lucky 
2 deg last-pass of the day.  But the short access did not
allow initializing the FTSCE solar cell experiment.  Without
another pass for 14 hours, we spent the next 24 hours
on a continuous telcon with our backup command 
stations making incremental progress in activating
the FTSCE experiment.

FTSCE was activated  7 hours later by our NZ station
but poor downlinks over 6 more passes yielded little
meaningful FTSCE data.  After 14 hours or so, on USNA's
first pass of the new day,we did get 44 of 54 data lines
and subsequent passes yielded similar results on the
next 6 USNA passes.

By mid-day, the automatic WEB page telemetry was
beginning to work and ALOGGER data collection was
working very well from SOuth Africa and the western
USA.

Battery voltage remained nominal at 14 volts and peak
charge as high as 1.5 amps out of a possible 1.8 amps
were observed even at this 25 or so degree beta
angle.

Once FTSCE data was flowing, we activated and tested
the PSK-31 transponder and voice repeater.  Both
were nominal.  On the 1755z pass the PSK-31
transponder was left on for a whole orbit and the
fail-safe timer properly reduced the duty cycle to
50%.  We successfully turned it off on the last
1930z pass for the day.

Final settings were also made to reduce telemetry 
from 10 sec to 20 sec in order to halve the TX power
used over the next 14 hours of no access.  Also
telemetry was reduced to only the 1200 baud
set and not the 9600 baud courtesy copy.  The
FTSCE beacon was left on.

NASA Glen also was getting good data by the
end of the day and was satisfied with the quantity
to allow analysis.  Overall, no system anomolies
were observed.  All voltages and currents
were nominal.  Temperatures did decay from about
10C initially down to about 4C over the 32 hour
period.

Most stations did observe better signals during the
first half of most passes probably due to ISS attitude
and PCSAT2 blockage.

Also the decision was made at JSC that PCSAT2
would not have to be shut down on every EVA or
arm operations, but only if operations were 
within 14 meters of our antennas.

After more than 36 hours of continuous operation
at USNA operations on PCSAT2 were secured and
efforts shifted to ANDE final integration items that
are due on Friday at NRL.

Many thanks to our volunteers in CA, NZ, AUS,
and the UK who remained on-line with us for more
than 24 hours until initial operations were nominal.
Also thanks to the Telemetry and APRS web-
master volunteers, software authors and amateur
radio volunteer ground stations who made
the global data collection effort possible.

Bob Bruninga
USNA Satellite Lab






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