Satgen 21   Mystery Sat Hilat  by GM4IHJ
With the 105 minute orbiter firmly identified as Polar Bear, it is
noteworthy that mystery sat number 2, has again been active recently.
It uses 137.676, 413.028 and 435.974 MHz, as does Polar Bear, but the 
413 signal is very weak. Its period is 100.9 minutes and its passes 
near UK get 27.5 minutes earlier each successive day. The frequencies
suggest that it is definitely HILAT, the partner to Polar Bear in the 
UCLA Polar Beacon and Auroral Experiment which forms part of the big
HISAT experiment presently underway from the UCLA station in Alaska.
But a search of official launch data has not yet produced a sat called
Hilat. Perhaps it launched under a different name, but it is clearly 
such a good fit to the UCLA data that I will be calling it Hilat from
now on.
Hilat appears to have an orbital inclination of about 82 or, 98 degrees.
It is strongest on 137 MHz, and this is frequently the only signal heard
clearly when it is near UK. It may also send telemetry on the 137 MHz 
channel , several passes of Hilat have been accompanied by telemetry
With its weak signals on 70 cms , it is not creating any problem on 
Oscar 13. Although one operator was heard to complain about " the 
station tuning on the frequency ".Typical pass times have been :-
Aug 17 1022 utc cpa. Aug 18 0955 1138  Aug 19 1252 1433
Aug 20 0903 1045 1229 Aug 21 1018 1200 1341 Aug 22nd 1133 1314 ut

Packsat Ground Terminal Developements
Computer simulation shows that with Packsat dopplering at up to 3KHz per
minute, packsat operations will be very demanding. So no one is expecting 
the majority of Radio Amateurs to use packsats directly. What we need are
unattended user transparent gateways which accept traffic like bulletin
boards , then fire it up to the sats at a convenient pass with no operator
involvement. Incoming messages will be downloaded for registered users at
the same time and held on the gateway bbs. A big problem is reception. It
looks as if a sensitive omni aerial will be OK but how do we keep the
BPSK in the receiver bandwidth as the signal dopplers. You could use 
expensive AFC, but IHJ is presently testing using a CAT controlled FRG
9600 rx driven by doppler prediction software to see if that might work.

Stop Press. Now Hilat is on, Polar Bear has been off on some but not all
orbits this week.  GM4IHJ 23rd August 89