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PCSAT2 Operations Notes



PCSAT2 has been thorugh a critical 4 days of
experiences and commanding.  But hopefully
we are back to OPS-normal.

Here is a summary:
1) A re-configuration for the Monday ARISS School contact
2) A random reset Monday night
3) Recovery taking most of Tuesday due to not having
   primary ground station access for 14 more hours
4) Rising temps and overcharging due to ISS change in
    station keeping attitude
5) All day Wednesday management of battery volts
    by turning on everything including 1.8 amp shunts.
6) Got everything back to normal that night but were
starting to get reports from PSK-31 users that the
uplink receiver was dead.
7) Followewd by a second 1 AM random RESET.

Working backwards, all events have now been
explained and all anomolies traceable to a series
of events complicating our learning experinece
on this new bird (attached to a big object in
space over which we have no control as to 
attitude)!  And oh-by-they-way, surviving
a Solar Storm!

>"AURORA STORM: It's over. A geomagnetic storm 
>that began on August 24th when a coronal mass 
>ejection hit Earth has subsided....

Thus, the RESET was caused by an SEU.  Which
we survived well. AND The lack of PC2PSK uplink
receiver was because the Solar Storm cause the
ionosphere to block uplinks on 29 MHz...

As far as all the work on the temps and battery,
we have been operating around, things are
are starting to come back down now.  This was 
all caused by ISS going from YVV to XPOP attitude 
to account for the changing beta angle...

We will anticipate this next time and just shut down
the PC2PSK transponder for a week to avoid the
temperature extremes (30C ambient plus, fully
charged batteries (16v), yielded XMTR PA temps
of 75C which was pushing Junction temps up to
near 150C which is the max for our transistors.)

So after 4 days of critical operations, looks like
all is explained, understood and learned and
OPS are now NORMAL. 

Next mode change will be for the 2 Sept ARISS
voice contact over Japan.

Enjoy! the 29 MHz CW/PSK-31 narrowband transponder!

http://www.ew.usna.edu/~bruninga/pec/pc2ops.html

Bob Bruninga, WB4APR
USNA Satelltie Lab
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