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[aprssig] Fwd: ISS/PCsat Joint Ops report

Robert Bruninga bruninga at usna.edu
Sat Feb 5 01:12:01 UTC 2005


Joint Ops Success #3:

During the 2300z pass over the Western USA PCsat was
leading ISS by about 8 minutes and both were operating
on 145.825 MHz for UIdigipeating.

Dozens of stations were seen, but at 2259z and2302Z, 
K7OFT in Seattle was successful with a packet through 
ISS to PCsat and down to everyone in the footprint.  
At that time ISS was about 1000 miles out over 
the North Pacific and PCsat was over Eastern Arizona. 

It was only thorugh the efforts of our West Coast PCsat 
command station, N6CO, that this happened in time.  On
the previous Pass, at 2119z over central USA, PCsat
reset back to W3ADO-1 and yours-truely was out getting
the kids from music lessons.  I was copying packets on
my D700 mobile when everything just stopped.  Using
the P.MON button I could see that PCsat had reset back
to the W3ADO0-1 callsign, but I was miles from my command
station.

I got back just 30 seconds after LOS!  A quick call to
Doc, N6CO, and he fired up his station high up in the
mountains of California and was ready with AMPS on
to restore the necessary parameters. 

PCsat came above the horizon, but there were very few
packets.  Evedryone was honoring the request to only
digipeat through PCSAT-1 and not the reset callsign of
W3ADO-1.   He waited, until he could get a good shot
for the loggon attempt. And then sent the PCSAT-1
callsign change.  Before he even got an ACK for the
command, we saw at least a dozen successful digipeats.

The activity was so great that it had completely scrolled
off the live downlink page: http://pcsat.aprs.org even
before the pass was 70% complete.

This is only day 2 of the test, but since PCsat will re-enter
eclipses tomorrow, it is doubtfull that we will be able to
keep PCsat alive...  But we will try.  RULES TO LIVE BY:

1)  No dark ops
2)  No morning ops when PCsat is West of you (its in the dark)
3)  DIGI via PCSAT-1, or WIDE callsigns only
4)  Do not even transmit if W3ADO-1 is the call.  Your packets
     are jamming the uplink making it difficult for the command
     station to loggon and fix it!  

5) EXCEPTIONS to this rule are for HAWAII and Alaska 
    stations attempting very long over-ocean hops.  They 
    may use the W3ADO-1 call even if PCsat has reset,
   because we do not want to miss this opportunity.

It is intersting to note that PCsat and ISS orbits are almost 
right on top of each other at this time period,  But ISS being
lower, it goes faster.  So  you have to wait for ISS to LAP
PCsat for these joint ops periods to occur.

PCsat's period is 101 minutes, and ISS's is 92 miunutes so
it takes about 10 orbits for ISS to "lap" PCsat.

The next Event will be an excellent opportunity to make
Packets from Hawaii to CONUS at 1524Z  using the
path of VIA RS0ISS-3,PCSAT-1.  But this is well before
sunrise in Hawaii and PCsat will also be in mostly darkness.

This is why ONLY HAWAII stations should transmit  using
the above path and NOT THE REVERSE.  Everyone
else should just listen in the USA until after PCsat is well
over canada and in good sun again.   Another good
Hawaii-to-Alaska dual hop path is poosible at about 1703z.


Good Luck!

Bob, WB4APR
US Naval Academy Command Station




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