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[jamsat-news:1228] * SpaceNews 14-Feb-00 *

* SpaceNews 14-Feb-00 *

BID: $SPC0214


		 	MONDAY FEBRUARY 14, 2000

Assi Friedman, KK7KX / 4X1KX, reports "unfortunately, it appears that the
ASUSat-1 satellite has stopped transmitting".  Received telemetry has
indicated the batteries aboard the satellite did not receive any charge
from the solar-array.  Because of this, the satellite worked for about
15 hours on battery power alone.  KK7KX reports the ASUSat-1 team has no
indications at this time to pinpoint the exact cause.  The team is looking
at the relationship between the solar-array and the power-board.

According to Assi, "the ASUSat1 team is disappointed but yet very happy.
The satellite provided interesting telemetry when it was alive, and we are
analyzing the data at present.  We were thrilled that the system powered up
and did what it was supposed to.  In any case, the team is looking forward
to future missions!"

ASUSat-1 contained an amateur packet hardware system and a 2-meter/70-cm FM
voice repeater.

The Air Force Minotaur had rocket successfully lifted off from Vandenberg
Air Force Base with a number of satellites onboard, including the Joint Air
Force-Weber State University Satellite (JAWSAT), Stanford University's
Orbiting Picosat Automatic Launcher (OPAL), the Air Force Research Lab's
Optical Calibration Sphere, along with ASUSat-1.  The primary payload was
the US Air Force Academy's FalconSat.

[Info via the AMSAT-NA News Service]

For anyone interested in tracking StenSat, controllers would appreciate full
details of all contacts, including AOS and LOS times, signal strength, and
tracking angles.

Controllers have received a half dozen reports so far that seem to indicate

* StenSat is leading in front of OPAL by about 1 minute.

* StenSat is in transponder mode (No CW or AX.25 has been reported).

Controllers suspect that StenSat is rapidly moving away from OPAL.  While it
remains on the same orbital track, it either leads or trails OPAL by some as
yet to be determined amount.  Based on the rapid deceleration of the Aerospace 
(tethered) picos, controllers suspect StenSat is leading OPAL.  If its
deceleration is on the same order as the Aerospace picos (circa one minute
ahead per day after ejection), StenSat might be found around one to two
minutes ahead of OPAL, but this is just a guess.

Hank Heidt, N4AFL ias created a StenSat Signal Report web page that may be
found at the following URL:


[Info via Hank Heidt, N4AFL]

Launch of the International Space Station's next component, the Zvezda
service module, is scheduled to occur between July 8 and 14 from the
Baikonur Cosmodrome in Kazakhstan, according to NASA and the Russian
Aviation and Space Agency.  The Zvezda launch window will be proposed
for approval to the International Space Station Partners in accordance
with the ISS Control Board process within the next several weeks.

Following joint meetings in Moscow, including a General Designer's Review
and a Joint Program Review, Rosaviakosmos has proposed that Zvezda (Russian
for "Star"), the early living quarters for crews aboard the station, be
launched on a Proton rocket with second and third stage engines modified
to increase reliability.

The 42,000 pound Zvezda not only provides the early living quarters for
astronauts and cosmonauts, but also the life support system, electrical
power distribution, data processing system, flight control system, and
propulsion.  While many of these systems will be supplemented or replaced
by later U.S. station components, Zvezda always will remain the structural
and functional center of the Russian segment of the International Space

Zvezda has a solar-array wingspan of 97.5 feet tip to tip, and is 43 feet
long from end to end.  The module contains three pressurized compartments
and four docking ports.

Following Zvezda's launch and about 15 days of free flight, the ISS will
rendezvous and dock with its newest module.  Launch of Zvezda sets the stage
for the launch of other ISS components undergoing final testing at NASA's
Kennedy Space Center in Florida.

These components include a small truss segment that will serve as the support
structure for other station hardware; the first set of solar arrays; the
United States Destiny laboratory; the Canadian-built space station robot
arm; and several truss segments that will serve as the station's backbone
for external hardware, experiments and solar arrays.  Other key station
components are also under development and testing in Europe and Japan.

[Info via NASA by way of Roy Neal, K6DUE]

Not being too happy with the AMSAT-BB archives on the AMSAT server, Jeff
Davis, N9AVG started archiving the AMSAT discussion messages in HTML format
on his own machine.  The result is an indexed archive that can be sorted
by month, date, author, subject and thread.  Jeff added the HT-Dig search
engine for complete word/phrase searches.

The Web-based archive may be found at:


[Info via Jeff Davis, N9AVG]

SUNSAT is equipped with a high resolution imager capable of filling 
the 64 MB ramtray in a matter of seconds.  However, because of the 
failed 40 Mbit/s S-band downlink, controllers are forced to download
data at only 9.6 kbit/s.  With about 40 minutes of useful download time
per day, this is getting extremely boring (not to mention the frustration 
for not being able to capture such wonderful images more often).

Controllers are investigating ways to better utilize the NBFM data channels 
available on VHF and UHF.  The satellite's 40 MHz Motorola DSP56L002 
platform has been commissioned at the end of last year.  The SNR on 
the 8W downlink is extremely favorable (it still has to be measured 
for capacity calculations).

The effective data rate could be increased by pre-processing of the 
image data and/or by implementing more complex modulator-demodulator 
pairs.  A simple compression routine running on the DSP already 
results in an effective rate of 15k36 bit/s.  Because of the high SNR 
the 9k6 modems can also be overclocked with limited success (up to a 
30% increase in the data rate before ISI becomes a limiting factor).  
This option could be pushed a little further by increasing the IF 
bandwidth of the receivers.

Any pointers to existing DSP56000 code for compression algorithms 
(like JPEG, wavelet and the like!) and/or modems implementing complex 
constellations would be most welcome.  Also, ideas on the suitability 
of ITU recommendations for telephony modems (such as V.34) would be
appreciated.  Controllers would like to know if these protocols be
used for simplex transmissions, or if there may be other ways to
increase the data rate.

Information should be directed to Johann Lochner, ZR1CBC, via e-mail at:


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/
MAIL:       John A. Magliacane, KD2BD
            Department of Engineering and Technology
            Brookdale Community College
            765 Newman Springs Road
            Lincroft, New Jersey 07738
INTERNET:   kd2bd@amsat.org, magliaco@email.njin.net

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