dna@dsd.UUCP (03/06/84)
Posted: Sat Mar 3, 1984 9:42 PM PST Msg: MGIE-1731-3168
From: TCLARK
To: AMSAT
Subj: U-O-11 nil report
Rip's report is confirmed here by another EMEer, W4DFK. Dana and I will
both be listening tomorrow AM.
Posted: Sat Mar 3, 1984 10:07 PM PST Msg: GGIE-1731-3182
From: JHOLLADAY
To: AMSAT
Subj: BIG EARS IN THE WEST
Harold Price contacted me this afternoon (Saturday) and requested
help with getting one or more well-equipped moonbounce stations
on the west coast to look for signals from UO-11. I started with
Lance Collister, WA1JXN, in Frenchtown, Montana, and he put me
in touch with K6MYC and W5UN. We were fortunate to have all
three stations operational and available to help with the search
tonight. That's the good news.
The bad news is that none of them heard any signals from UO-11.
Thse are three of the best-equipped moonbounce stations in the
West, and if none of them could hear a signal, there was probably
no signal to be heard. Their antenna setups and locations are:
WA1JXN, Frenchtown, MT 12 X 19-element Boomers
W5UN, Midland, TX 16 modified Quagis with 26 ft booms
K6MYC, San Martin, CA 8 long yagis with 28 ft booms
All stations are using good GASFET preamps located at the
antenna. Predicts were run by W6PAJ using UO-11 element set
No. 4, and W5UN also ran predicts using the same element set.
The following shows the times of the passes that were checked
and predicted maximum elevations (4 March UTC date):
WA1JXN 0300-0311Z (14 deg) 0436-0449Z (79 deg)
W5UN 0255-0306Z (17 deg) 0431-0444Z (38 deg)
K6MYC 0434-0446Z (33 deg)
So, we gave it a good shot and the results are not encouraging.
Each station agreed to try one good pass tomorrow morning in
hopes that being in sunlight will coax some signal out of
the satellite. They will call me if any signals are heard, and
I will notify Harold right away.
We owe each of these operators a big "thank you" for responding
quickly and well to our request for help. It was a pleasure to
work with them.
Here's hoping contact can be re-established with UO-11. 73.
Jay Holladay, W6EJJ
Posted: Sun Mar 4, 1984 5:57 AM PST Msg: AGIE-1731-3276
From: MSWEETING
To: AMSAT
Subj: UoSAT-2 Status report
** UOSAT-2 SPACECRAFT OPERATIONAL STATUS **
4th March 1984 0800 gmt
Following a flawless launch on DELTA 174 from Vandenberg Air
Force Base, Ca., UOSAT-2 separated from the launcher at approx
19:11 gmt over Turkey and in range of the Command Station at
Surrey. A lengthy series of instructions was transmitted to
the spacecraft to establish the initial operating conditions
and then the s/c computer was instructed to switch the 145.825
MHz downlink on for 10 secs to check housekeeping data and
ensure that outgassing of the beacon did not give rise to
corona. The spacecraft responded perfectly first time and good
data was received & decoded at Surrey. The 145 MHz beacon was
then activated for several minutes, under computer control,
and further data gathered which confirmed that the spacecraft
was in very good shape. Just prior to LOS at Surrey, the
computer was instructed to activate the beacon once more for a
further 4 minutes and good data was received as the spacecraft
disappeared over the horizon.
On orbit #2 the 145 MHz beacon was re-activated by
abreviated computer instructions and the short and long bursts
of telemetry repeated - data indicated everything on the
spacecraft to be entirely nominal and so the computer was
instructed to keep the 145 MHz beacon active in check-summed
telemetry at 1200 bps for the next 80 minutes.
The spacecraft arrived at UoS silent (as expected) at AOS
on orbit #3 and the short and long bursts of telemetry data
process was repeated - data again indicated the spacecraft to
be entirely nominal and so the computer was instructed to
activate the 145 MHz beacon for the next 10 hrs whilst the
spacecraft was out of range of the Surrey station.
With all having proceeded perfectly to plan thus far, the
UoS team relaxed (collapsed?) and waited for telemetry reports
from around the world!
The first indications that all was not well came from the
printer when Larry Kayser wanted to know why he could not hear
UO-11 followed by t/m from Phil Karn etc. The UoS Command Team
were 'revived' and awaited the first pass of the day, orbit
#8. The spacecraft was silent (again as expected) at AOS,
however repeated attempts to re-activate the 145 MHz beacon
using the s/c computer failed as did direct command. Heated
analysis of the situation resulted in the preliminary theory
that the 'Watch-Dog' timer (a device that de-activates the 145
& 435 MHz beacons after 21 days if no commands have been
detected from the ground - remember UO-9!) may have been
incorrectly initialised and thus may have terminated
transmissions prematurely. The 'Watch-Dog' can be reset by
command and this, and re-activation of the 145 MHz beacon,
were attempted on orbit #9 - however with no success.
Continued attempts on orbit #10 yielded nothing and things
began to look rather grim. At that time no reason could be
found for the premature shut-down of the beacon and the
prevailing theories tended towards cataclysm. Additionally,
t/m 'went down' and we had to resort to phoning around to
gather more pieces of the picture! Data from G.Ratcliffe via
phone from Australia confirmed that the spacecraft systems
were functioning nominally when he tracked UO-11 just before
termination of transmissions. The spacecraft was in very good
shape!
Detailed examination of the s/c computer software used
during the first few passes shewed that the timing had been in
error - the timing clock selected had been running at 8 times
that required - resulting in premature shut-down of the beacon
on both orbit #2 and #3 entirely in agreement with
observations! This now veered the theories away from the 'Big
Bang' and towards some sort of spacecraft systems problem.
Lack of feedback from the spacecraft keeps us effectively
blind and all we can do is postulate the most likely theories
based on pre-launch experience. The current theory is that
there may be a problem with the 145 MHz beacon causing it to
fail to operate correctly and generate wide-band noise and
block the command receivers. This theory is based on
observations of the performance of the beacon during test
where some problems of this nature were encountered but were
later believed to have been fixed. The Surrey Command Station
are continuing to attempt to command the 145 MHz beacon OFF
and the 435 MHz beacon ON - so far without success. If the 145
MHz beacon is ON but not operating correctly, it should be
possible to observe it with high gain antennas and spectrum
analysers etc. Should this prove to be the case, then it may
be most profitable to attempt to command the spacecraft using
the 1.2 GHzcommand uplink as this uplink is the most
independant of the VHF/UHF systems.
All we can do is try out various theories - we tend not to
favour total system failure or spontaneous detonation at
present rather some more limited scenario. We shall keep you
posted as to our thoughts and progress. Needless to say,
everyone here is somewhat disappointed after the efforts of
the last months and such a flawless start to UO-11's life!
We still have faith, though!
Martin Sweeting UoSAT Programme Manager
+ UoS Team
Posted: Sun Mar 4, 1984 4:32 PM PST Msg: PGIE-1731-3751
From: JHOLLADAY
To: amsat
Subj: NOTHING HEARD
I have had no reports of signals heard from any of the morning passes
which were monitored by WA1JXN, W5UN, or K6MYC. No further requests
will be made for those stations to do more monitoring unless I get
an input to do so from those working on the UO-11 problem.
Good luck!
Posted: Sun Mar 4, 1984 8:24 PM PST Msg: EGIE-1731-4120
From: TCLARK
To: amsat
Subj: 'IWI Program Questions
Several people have been asking questions and as a result creating rumors
about errors in my prediction program. To dispel some comments/rumors that
have been heard in the last day or two:
(1) The program code as it appeared in ORBIT is correct for handling satellites
with inclinations > 90 degrees. Any stories to the contrary are wrong.
(2) Two versions of the program ended up with minor typographical errors
involving the same line of code. The K0RZ version for APPLE II has an
error in about line 330 where the code reads "IF M > 1 THEN ...." -----
the correct code should read "IF M > 2 THEN ...."
(3) N5AHD has reported a bug similar to (2) for the IBM-PC. It is documented
on the AMSAT BB but involves a line which reads "IF M > 2 THEN ...." which
should read "IF MONTH > 2 THEN ....".
To my knowledge there are no other errors in the code distributed. The code
WILL work for UoSAT as it stands. The problems in finding UoSAT are not due
to the prediction software. Predictions made here using my "master" copy
on North Star agree with KA9Q's predictions made with independently developed
software running on a VAX.
73, Tom
- - - - - - - - - -
Attempts to hear using stations with "big" ears (K1WHS, W4DFK),
on the east coast have proven negative thru Sat. Nite.
Sun. AM attempts at W3IWI (within abt 2 dB of EME capability)
have also proven negative. 73, Tom
- - - - - - - - - - -
Posted: Mon Mar 5, 1984 7:02 AM PST Msg: IGIE-1731-5684
From: TCLARK
To: amsat
Subj: U-O-11 and Landsat D' Element Set #5
Here follows another new set of UoSAT-Oscar-11 Keplerian elements:
Object: 1984-021B = NASA # 14781
NASA El.Set: # 5
Epoch: 84064.46078527
Incl: 98.2551
RAAN: 126.9087
Eccr: 0.0012928
Arg.Perg: 253.6204
Mean Anom: 106.2574
Mean Motion: 14.61847144
Drag: +0.00034629
By popular request, here are elements for Landsat-D':
Object: 1984-021A = NASA # 14780
NASA El.Set: # 5
Epoch: 84064.46281564
Incl: 98.2545
RAAN: 126.9100
Eccr: 0.0010697
Arg.Perg: 274.5334
Mean Anom: 085.4451
Mean Motion: 14.60712266
Drag: +0.00010338
73, Tom
Posted: Mon Mar 5, 1984 8:47 AM PST Msg: CGIE-1731-6758
From: HPRICE
To: AMSAT
Subj: To the Big Ears crew.
Please compute the minimum strength signal you would expect to be able to hear
from the uo-11 orbit at your station. We would like to try to hear the local
rx oscillators on uo-11. Exact frequencies later, but they will be around
134 MHz.
- - - - - - - - -
My comments on Harold's msg: Most of the EME arrays are quite narrow band.
They are probably already down 1-3 dB at 145.8 MHz. I hold little hope
that they will hear anything 12 MHz = 8% away from their design freq. If
this is important, it would be best to try to find some station with a big
(e.g. > 30') dish and throw together a special feed. We should also arrange
for either Lunar or ARR or ??? to get a GaAsFET preamp done for us quickly.
To mount this test will be a fairly big deal. Is it really worth it?
73, Tom