* Listen to the new Microsats * Bulletin-ID: 34842_W3IWI * de DB2OS @ DK0MAV *

R:900123/0535z 34842@W3IWI.MD.USA [Balto/Wash MD/DC/VA/DE] Z:21029

As you have probably heard, six new amateur satellites were launched on
schedule Sunday night, Jan.21 (about 01:36z on 1/22) following a one day
delay because of bad weather at Kourou. With that launch we now have
OSCAR-19 (and 14, 15, 16, 17 and 18) all in orbit.

All four Microsats (-16 thru -19) and both UoSATs (-14 and -15) have now all
been brought to life and all indications are that everything is nominal.

Of the Microsats, three (PACSAT, LUSAT and WEBERSAT) are transmitting 1200BPS
PSK packet telemetry in the 437 MHz range. LUSAT is also transmitting CW on
437.125 MHz.

The fourth Microsat, DOVE has a 2M downlink on 145.825 which later will be
transmitting synthesized voice, but now it is sending ordinary 1200 BPS
AFSK-FM packet telemetry which anyone can copy with a "stock" TNC and
2M FM radio -- no special equipment required!  On the last pass I was
even able to hear DOVE well on my HT with a rubber duckie when it was 2800 km
away, about 5 degrees above the horizon. On the radio I normally use for the
W3IWI PBBS, DOVE is as loud as many local area packet users. DOVE's 2 watt
2M xmtr puts out a potent signal!

All 6 spacecraft are in essentially the same sun synchronous orbit. In the
northern hemisphere you will get two or three evening passes in a window
centered on 10PM local time, and two or three morning passes centered on
11 AM local time -- all the passes you can hear will be between plus/minus
two hours from these times.

So if you want to copy the packet signals from DOVE flying 800 km up, just
crank your 2M FM rig to 145.825 and leave your TNC in the monitor mode.
It will transmit for a couple of minutes and then stop for 30 seconds.
To decode the telemetry from any of these satellites, watch the ALL@AMSAT
packet bulletins distributed by AMSAT for more details.

And there's more to come -- the Japanese plan to launch OSCAR-20 next
month, and astronaut Ron Parise, WA4SIR will have packet radio hardware
onboard the next flight of the Shuttle Columbia (STS-35) in April.

If you are proud of these amateur achievements, please contact AMSAT
for more information on how YOU can participate in these amateur space
activities.

73 de Tom, W3IWI
.z.z.q.

* MICROSAT UPDATE * Bulletin-ID: ANS-055.02 * de DB2OS @ DK0MAV *

HR AMSAT NEWS SERVICE BULLETIN 055.02 FROM AMSAT HQ
SILVER SPRING, MD FEBRUARY 24, 1990
TO ALL RADIO STATIONS BT

Week five at the AMSAT Satellite Factory (tm) finds the Engineering Team
focusing their attention on investigations of the spinning motion of each
satellite and the accompanying effects on solar cell illumination and
temperature. All four satellites have some degree of wobble motion in
addition to spin and magnetic lock. Jim White (WD0E) and a number of
other volunteers have put forth considerable effort aiding W3GEY, N4HY,
and NK6K in evaluating the telemetry from each satellite to characterize
its various motions.

AO-16 seems to have the most wobble of all the MICROSATs. It currently has a
rotational period of 690 seconds (which is fairly slow) and a wobble of about
45 degrees. LO-19 takes about 270 second/rev and has a wobble of about 20
degrees. DO-17 is the most stable of all the satellites with its 20 second
rotational period and a wobble of about 12 degrees. Data on WO-18 is still
being analyzed. Because WO-18 has two additional trays (a total of 7
electronic platforms) its spin characteristics are more complex and will
require further study.

Because of the shortage of real estate and modest power budgets, none of the
MICROSATs has an active attitude control system on board e.g., magnetorquing
coils such as those used on AO-10, UO-11, AO-13, and UO-14. They do, however,
have a set of bar magnets placed along each of the four corners of the
spacecraft which will provide some alignment with the earth's magnetic field
and will ultimately damp the wobbling motion. In addition, the 70 cm antenna
elements on each satellite are painted black on one side and are silver coated
on the other side. The purpose of painting only one side is to generate a
slight rotational torque due to solar radiation on the MICROSAT to keep the
satellites rotating. This solar torque drives each satellite in constant
rotation and thus prevents one part of the spacecraft from becoming too hot
or too cold.

Once it has been determined that each satellite's battery charging and
temperature parameters have stabilized, preliminary operating schedules will
be drafted and the satellites released for general use. Look to ANS for late
breaking news on the commissioning of the MICROSATs.