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[jamsat-news:1092] * SpaceNews 24-May-99 *
SB NEWS @ AMSAT $SPC0524
* SpaceNews 24-May-99 *
BID: $SPC0524
=========
SpaceNews
=========
MONDAY MAY 24, 1999
* SUNSAT SUCCESS *
==================
SUNSAT controllers are happy to announce that successful reception of PAL
television images from SUNSAT have been received last week. The commercial
grade TV camera on-board SUNSAT is connected via a MUX to the satellite's
S-Band transmitter, and the images received at the Overberg Test Range
as well as the SUNSAT ground station.
The signal strength of the S-Band transmitter was constant throughout the
pass, and the images of oceans with some clouds of South Africa marks a
milestone in the commissioning of SUNSAT. The image covers an angle below
the satellite of 90 degrees and two of the antennas are visible on the
image. On the ground directly below the satellite it covers a width of
450km. The image is three color, and the colors are bright and vibrant.
The congratulations goes to our ground station engineers and lecturers who
committed to achieving this milestone.
SUNSAT's history so far:
23 Feb : Launch (after MANY attempts!)
24 Feb : Switched telemetry transmitter on and heard first signals
25 Feb : Recorded and analyzed first telemetry
26 Feb : More telemetry, first switch on of OBC1, 'I'm alive'
27 Feb : Boom deployment, more telemetry,
28 Feb : Uploaded first diary to OBC1 to initiate 10 min interval diary,
downloaded in the USA
01 Mar : Restarted OBC1, uploaded diary to do WOD file over 70 min
03 Mar : Backup telecommand path verified
04 Mar : Y-axis torque coil working, estimators switched on
05 Mar : Estimators switched on, reliable communication day and night
06 Mar : SUNSAT attitude is stabilized and pointing to the earth
PHASE I COMMISSIONING COMPLETE - JJDP
14 Mar : SUNSAT's voice repeater is turned on and 38 radio amateurs
use it to talk to each other
21 Mar : SUNSAT Reaction wheels are used to rotate the satellite:
FIRST TIME FOR A GRAVITY GRADIENT SATELLITE
24 Mar : NASA JPL GPS receiver is switched on
25 Mar : Successful 128 kbyte code upload for ADCS and filters are converging
05 Apr : Calibration of ADCS actuators
12 Apr : Successful testing of software upload for OBC1
14 Apr : Successful rotation of imager tube
15 Apr : Groundstation repairs due to rain damage begin
21 Apr : First star mapper image downloaded and first imager sensor test
indicates all is functioning well
22 Apr : OBC software successfully uploaded
11 May : First images from the PAL TV imager on SUNSAT
13 May : First images with the PAL TV imager of South Africa
Further information on SUNSAT may be found on the Web at the following URLs:
http://sunsat.ee.sun.ac.za/
http://esl.ee.sun.ac.za/
[Info via Mostert S.]
* UoSAT-12 IMAGES *
===================
The recently launched UoSAT-12 Amateur satellite contains earth imaging
cameras capable of providing interesting views of planet earth from the
satellite's low-earth circular orbit. Some of UoSAT-12's recent images
have been made available on the Internet at the following URLs:
Detroit (32-metre 4-band multi-spectral image)
http://www.sstl.co.uk/primages/SSTL-UO12-msimage-Detroit.jpg (768 kB)
http://www.sstl.co.uk/primages/SSTL-UO12-Detroit-Metro-Airport.jpg (86 kB)
http://www.sstl.co.uk/primages/SSTL-UO12-Detroit-buildings.jpg (157 kB)
Los Angeles (10-metre panchromatic image)
http://www.sstl.co.uk/primages/SSTL-UO12-pan-LA.jpg (443 kB)
Ontario (10-metre panchromatic image)
http://www.sstl.co.uk/primages/SSTL-UO12-pan-Ontario.jpg (180 kB)
[Info via Chris Jackson, G7UPN]
* OSCAR-11 REPORT *
===================
During the period 15 April to 15 May 1999, reliable signals have been
received from UoSAT-OSCAR-11's 145.826 MHz beacon transmitter. Telemetry
shows that the battery voltage during daylight passes has continued to
decrease with the average value observed being 13.5 volts with 13.1 volts
recorded on one occassion.
The spacecraft's internal temperatures have continued to fall, and have
dropped by about two degrees C during the reporting period, primarily due
to increasing eclipse times. They are now 2.4C and 0.6C for battery and
telemetry electronics respectively.
The magnetorquer spin correction counters have now started to show some
activity. During the last month, the negative spin counter has started
to increment at about three counts per day, whereas previously it was
incrementing at about one count every three days. At the beginning of
April, there was a period when the Z-axis counter reached 1024, causing
the attitude control to stop. During this time, the spin rate remained
fairly constant, indicating that the spin rate did not require any
corrections, rather than a fault condition. The Z-axis counter continues
to increment normally at around 10 counts per day.
The WOD survey dated 08-April-1999 of channels 39, 50, 52 & 63
(telemetry electronics temperature, battery charge current, battery
voltage, and BCR status), has recently been transmitted by the satellite.
A plot of channel 52 (battery voltage) shows that during periods of
sunlight, the voltage can be seen rising and modulated by the spacecraft
spin. The shape of this modulation suggests that one photo cell panel
may be generating a smaller output than the others. During the eclipse
period, the voltage steadily decreases from 13.3 down to 12.2 volts.
Channel 63, which contains the battery charge regulator (BCR) status,
shows that the switch between A & B units occurs when the satellite
enters or exits from the eclipse state. Channel 39 (telemetry
electronics) shows a very small change in temperature, about one
degree C, of the telemetry electronics unit, as the satellite passes
through the earth's shadow.
The Mode-S beacon has been heard by Victor, OK1VKW. Victor uses a 40
element horizontal Yagi with an SSB UEK2000 converter into an Icom
IC-275 receiver. Signals were S2-3 at a range of 700 km.
OSCAR-11's operating schedule remains unchanged:
ASCII status (210 seconds)
ASCII bulletin (60 seconds)
BINARY SEU (30 seconds)
ASCII TLM (90 seconds)
ASCII WOD (120 seconds)
ASCII bulletin (60 seconds)
BINARY ENG (30 seconds)
The ASCII bulletin is currently a static message that details modes and
frequencies of all the amateur radio satellites.
There are additional status blocks after each bulletin is transmitted
as well as between ASCII TLM and WOD.
The Mode-S beacon is ON transmitting an unmodulated carrier, but
telemetry indicates that it has partially failed, and delivering half
power. This beacon is a useful test source for those testing Mode-S
converters prior to the launch of P3-D. However, the signals are very
weak, and there is a lot of Doppler shift. Users should also note that
the polarization of OSCAR-11 is left-hand circular. Even if you can't
hear OSCAR-11, your equipment may still be OK for P3-D. Any reports
of Mode S beacon reception on 2401 MHz would be most welcome and should
be directed to Clive Wallis, g3cwv@amsat.org.
The 435.025 MHz UHF beacon is normally OFF. However, it can sometimes
be heard when the satellite is being commanded by ground control, ie.
within range of Guildford, UK. When the 435 MHz beacon is transmitting,
the 145 MHz beacon is normally OFF. The data transmitted is mainly
binary.
Listeners to OSCAR-11 may be interested in visiting an OSCAR-11 web
site maintained by Clive Wallis, G3CWV. The site contains details
of hardware required and some software for capturing data, and decoding
ASCII telemetry and WOD (whole orbit data). There is an archive of
raw data (mainly WOD) for analysis that is continually being expanded
as new data is captured. Also included are some audio files containing
examples of each type of data transmitted by OSCAR-11. Each one plays
for about ten seconds. There are also examples of Mode-S reception.
All the audio files are compressed (zipped) so that they can be played
off-line. These files should help listeners identify the various
types of data, and give an indication of the signal quality required
for successful decoding.
The URL is: http://www.users.zetnet.co.uk/clivew/
[Info via Clive Wallis, G3CWV]
* FO-29 SCHEDULE *
==================
The FO-29 command station of has announced the following operating
schedule for the FUJI-OSCAR-29 satellite:
Mon 17-May-99 -to- Mon 24-May-99 : Mode JD (1200 baud)
Mon 24-May-99 -to- Mon 31-May-99 : Mode JA
Mon 31-May-99 -to- Mon 07-Jun-99 : Mode JD (1200 baud) - New
[Info via Kazu Sakamoto, JJ1WTK]
* STS-96 ORBITAL DATA *
=======================
Below is the nominal OMS-2 State Vector and Keplerian Elements for
STS-96. The vector data comes from NASA; the Keplerian Elements
were computed from the vector.
This file may be read by VEC2TLE version 9648 to update your
Keplerian Elements text file.
Vector format = 10117
Satellite Name: STS-96 OMS-2
Catalog Number: 99996
Epoch MET: 0.03060320602
0/00:44:04.117 MET
EFG E: 6189756.8 ft
F: 20637061.8 ft
G: -4356976.2 ft
Edot: -14999.991056 ft/s
Fdot: 439.532345 ft/s
Gdot: -19227.977369 ft/s
ndot/2 (drag): 0.00006404797 rev/day^2
nddt/6: 1.73581E-10 rev/day^3
Bstar: 3.92061E-05 1/Earth Radii
Elset #: 2
Rev @ Epoch: 1.54068956834
Launch scheduled: 1999-MAY-27 10:49:38 UTC
The following Keplerian elements were computed by VEC2TLE from this
vector and the nominal launch time, using a 0.5 drag multiplier:
STS-96 OMS-2
1 99996U 99147.48173747 .00006405 17358-9 39206-4 0 20
2 99996 51.5922 302.0826 0034903 206.1676 348.4700 15.75680771 10
Satellite: STS-96 OMS-2
Catalog number: 99996
Epoch time: 99147.48173747
Element set: 2
Inclination: 51.5922 deg
RA of node: 302.0826 deg
Eccentricity: 0.0034903
Arg of perigee: 206.1676 deg
Mean anomaly: 348.4700 deg
Mean motion: 15.75680771 rev/day
Decay rate: 6.40480e-05 rev/day^2
Epoch rev: 1
Checksum: 330
VEC2TLE may be downloaded from <http://www.mindspring.com/~n2wwd>.
[Info via Ken Ernandes, N2WWD]
* FEEDBACK/INPUT WELCOMED *
===========================
Comments and input for SpaceNews should be directed to the editor
(John, KD2BD) via any of the paths listed below:
WWW : http://www.njin.net/~magliaco/
PACKET : KD2BD @ KS4HR.NJ.USA.NA
INTERNET : kd2bd@amsat.org, magliaco@email.njin.net
SATELLITE : AMSAT-OSCAR-16, KITSAT-OSCAR-25
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/EX
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