Date: December 6th 2009

AMSAT NEWS SERVICE ANS-340

ANS is a free, weekly, news and information service of AMSAT North America, The Radio Amateur Satellite Corporation ANS reports on the activities of a worldwide group of Amateur Radio operators who share an active interest in designing, building, launching and communicating through analog and digital Amateur Radio satellites

Please send any amateur satellite news or reports to:

ans-editor@amsat org

In this edition: * Magnetic Flip Experiment Aboard AO-51 Successfull * OSCAR-11 REPORT 30 November 2009 * ARISS Status - 30 November 2009

SB SAT @ AMSAT $ANS-340 01 Magnetic Flip Experiment Aboard AO-51 Successfull

AMSAT News Service Bulletin 340 01 From AMSAT HQ SILVER SPRING, MD December 6, 2009 To All RADIO AMATEURS BID: $ANS-340 01

Since its launch AMSAT-Echo AO-51 has carried a spacecraft attitude adjustment experiment which was tested for the first time this week The experiment contains a "reversible" magnet which will align the spacecraft with Earth's magnetic field

On the December 2, 2242 UTC pass of AO-51 AMSAT-NA VP Operations Drew Glasbrenner, KO4MA issued the command to reverse the magnet and "flip" the orientation of the satellite The first effect of the experiment was expected to be some changes in signal levels and patterns AO-51's 435 MHz downlink was expected to become slightly weaker in the northern hemisphere and slightly stronger in the south- ern hemisphere

ZL2BX reported, "With two usable passes over ZL last night the most notable feature was the frequent polarity shifts Certainly good strong signals but difficult to tell how it compares to previous signal levels "

IW4DVZ reported results from a contact with EI8JB, "For me nothing changed, I received from AO-51 the same strong signal as usual "

W6ZKH reported the only difference were frequent polarity changes The signal strength here on the West Coast seemed to be the same as before

Tom Clark, K3IO offered an explanation for the received signal changes, "Since angular momentum must be conserved when you "flip" the space- craft it should precess (probably looking like tumbling) until the mom- entum dampers absorb the change Keep an eye on the solar panel currents and I'll bet the spin rate will change "

Drew concluded, "We are still sifting through the telemetry, but as Tom suggested in his email, the satellite is precessing (wobbling) quite severely This will calm down as the hysteresis rods do their job Ini- tial reports from Australia and New Zealand indicate stronger signals, and about the same from South Africa There are some peculiar things about the magnetic field near South Africa, so that doesn't surprise me too much, but is worth digging into once we get the whole orbit tele- metry down "

The AO-51 Command Team appreciates any signal reports or observations for the next few days that you can email to ao51-modes@amsat org or ko4ma@amsat org In a week or so the Command Team expects to re-orient AO-51 back to its original attitude

Twitter users can receive tweets from the AO-51 command team at http://twitter com/AMSAT or by adding "AMSAT" to your follow list

[ANS thanks the AO-51 Command Team for the above information]

/EX

SB SAT @ AMSAT $ANS-340 02 OSCAR-11 REPORT 30 November 2009

AMSAT News Service Bulletin 340 02 From AMSAT HQ SILVER SPRING, MD December 6, 2009 To All RADIO AMATEURS BID: $ANS-340 02

This report covers the period from 21 April 2008 to 30 November 2009

The satellite unexpectedly resumed transmissions recently It was first heard by Keith N4ZQ on 19 November 2009 and transmissions continued until it switched OFF on 27 November It was last heard by Tetsu JA0CAW at 23:59 UTC 26 November 2009 Previously, it was last heard by Peter ZL3TC on 23 April 2008, on a single pass

Study of the satellite's behavior had suggested that its battery would not sustain operation during solar eclipses, and the watchdog timer would switch the satellite OFF after less than an orbit Eclipses are now occur during every orbit and will continue for many years In practice this meant that OSCAR-11 would only be heard occasionally by stations monitoring the frequency while listening for other satellites

During this period of inactivity the satellite achieved 25 years in orbit on 01 March 2009 Congratulations to Professor Sir Martin Sweeting, his team at the University of Surrey and participating amateur radio groups, for this fine achievement

Good signals have been received by stations located all over the world during this recent period of activity and telemetry has been decoded successfully However, the satellite has only transmitted when in sunlight I have been overwhelmed by the number of reports received, too many to list individually! Many thanks to everyone who sent email reports or posted to AMSAT-BB

The telemetry is unchanged from the 2008 downloads The on-board clock is now 241 days slow When last received in 2008 it was 83 days slow The increasing error suggests that the clock may be stopping, when the satellite is in eclipse

The exact date when the satellite started transmitting is not known, so if the watchdog timer was reset, the next transmissions might start around 16 December, however if the timer went through its full operating cycle, transmissions could resume around 06 December

The Beacon frequencies are -

VHF 145 826 MHz AFSK FM ASCII Telemetry

UHF 435 025 MHz OFF

S-band 2401 5 MHz OFF

The satellite is now subject to eclipses during every orbit Long term predictions indicate that eclipses will occur until 2019, when there will be some eclipse free periods until 2023 However these very long term predictions should be regarded with caution, as large tracking errors can accumulate over long periods of time

When telemetry was last received it showed that one of the solar arrays had failed, and there was a large unexplained current drain on the main 14 volt bus After 25 years in orbit the battery has undergone over 100,000 partial charge/discharge cycles, and observations suggest that it cannot power the satellite during eclipses lasting more than about ten minutes, or sometimes even during periods of poor solar attitude

                     -------------

RECEPTION REPORTS REQUESTED!

Please send reception reports to xxxxx@amsat org (replace xxxxx by g3cwv) or post to amsat-bb If you have a file, please let me know what you have, before sending it!

The satellite transmits on 145 826 MHz , set receiver to NBFM OSCAR-11 has a characteristic sound, rather like raspy slow morse code, sending "di di dah dah dah dah dah dah dah" sent over five seconds If you are receiving a very weak signal, switch the receiver to CW or SSB You should hear several sidebands around the carrier frequency, should be able to hear the characteristic 'morse code like' sound on at least one sideband

Please note that you need a clean noise free signal to decode the signals There is an audio clip on my OLD website www users zetnet co uk/clivew/ which may be useful for identification and as test signal for decoding

                    -------------

The current status of the satellite, is that all the analogue telemetry channels, 0 to 59 are zero, ie they have failed The status channels 60 to 67 are still working The real time clock is showing a large accumulated error, although over short periods timekeeping is accurate to a few seconds per month When last heard the clock was 241 days slow The day of the month has a bit stuck at 'one' so the day of the month may show an error of +40 days for some dates The time display has switched into 12 hour mode Unfortunately, there is no AM/PM indicator, since the time display format was designed for 24 hour mode

The spacecraft computer and active attitude control system have switched OFF, ie the satellite' attitude is controlled only by the passive gravity boom gradient, and the satellite is free to spin at any speed

The watchdog timer now operates on a 20 day cycle The ON/OFF times have tended to be very consistent The average of many observations show this to be 20 7 days, ie 10 3 days ON followed by 10 4 days OFF However, poor solar attitude may result may result in a low 14 volt line supply, which may cause the beacon to switch OFF prematurely, and reset the watchdog timer cycle When this occurs, the beacon is OFF for 20 7 days

OSCAR-11 was the second satellite from the University of Surrey, www ee surrey ac uk/SSC It was designed, built and launched, within a time scale of six months, by a team headed by Martin Sweeting G3YJO Amateur radio groups working at various locations in the world, also contributed to the project It used commercially available 'off the shelf' components (COTS) Following the success of these satellites, in 1985 Surrey Satellite Technology Ltd www sstl co uk was formed, as a commercial venture This grew into a major company which has produced over 30 small satellite projects for a global market

The University of Surrey has recently sold it's major shareholding in SSTL to EADS-Astrium The joint company will therefore have the experience of manufacturing large and small satellites, for geo-synchronous and low earth orbits

In regognition of his work, Martin G3YJO, was appointed Professor at the University of Surrey He received an OBE in the 1995 Queens birthday honours list, and in 2002 a knighthood in the New Year's honours list

Listeners to OSCAR-11 may be interested in visiting my websites If you need to know what OSCAR-11 should sound like, there is a short audio clip for you to hear The last telemetry received from the satellite is available for download The website contains an archive of news & telemetry data which has now been updated It also contains details about using a soundcard or hardware demodulators for data capture There is software for capturing data, and decoding ASCII telemetry The URL is www users zetnet co uk/clivew/ However, please note that this site is no longer being updated, and the latest news and information will and will be uploaded to my new site www g3cwv co uk which is currently being constructed

If you place this bulletin on a terrestrial packet network, please use the bulletin identifier $BID:U2RPT145 CWV, to prevent duplication

73 Clive G3CWV xxxxx@amsat org (please replace xxxxx by g3cwv)

[ANS thanks Clive, G3CWV, for the above information]

/EX

SB SAT @ AMSAT $ANS-340 03 ARISS Status - 30 November 2009

AMSAT News Service Bulletin 340 03 From AMSAT HQ SILVER SPRING, MD December 6, 2009 To All RADIO AMATEURS BID: $ANS-340 03

De Winne Speaks with Dumbleyung Primary School through ARISS

On Thursday, November 26, Dumbleyung Primary School in Western Australia took part in an Amateur Radio on the International Space Station (ARISS) contact with Frank De Winne, ON1DWN via telebridge station VK4KHZ in Australia To prepare for the contact, students studied Earth, its structure and the solar system As part of the ARISS event, students in Years 5 -7 gave presentations of their space work and viewed footage of the ISS as well as video of an astronaut interview All 21 children had their questions answered during their radio contact and ABC (Australian Broadcasting Corporation) News covered the event

Don Bosco Institut Experiences ARISS Contact

On Thursday, November 26, an Amateur Radio on the International Space Station (ARISS) contact was held between Institut Don Bosco in Bruxelles, Belgium and Frank De Winne on the ISS The connection was made possible through telebridge station ON4ISS in Belgium Students asked 19 questions of the astronaut during the ISS pass Don Bosco is a secondary industrial technical school with an enrollment of approximately 750 students and offers courses in carpentry, electricity, mechanics, computing, printing and electronics

ARISS Contact held with Katholieke Centrumscholen Sint-Truiden Students

Students attending Katholieke Centrumscholen Sint-Truiden in Sint-Truiden, Belgium experienced a successful Amateur Radio on the International Space Station (ARISS) contact with Frank De Winne on Thursday, November 26 via telebridge station ON4ISS in Belgium Twenty questions were asked and answered In order to prepare for the radio contact, the students studied astronomy and science In addition, the school headmaster talked to the youth about the ISS and his own experiences during two Ã‚Â“space campsÃ‚Â” in the U S (Huntsville and Kennedy Space Center)

ARRL Covers Installation of Columbus Module Antennas

The American Radio Relay League (ARRL) ran an article about the new antennas that were installed on the Columbus module To view the story, which ran in the November 25 issue of the ARRL Letter, see: https://www arrl org/arrlletter/index html?issue=2009-11-25

ARISS News on Amateur Radio Newsline

On November 27, Amateur Radio Newsline Report 1685 reported on the new Columbus module ARISS (Amateur Radio on the International Space Station) antenna To view Ã‚Â“Ham Radio in Space: ISS Gets New Dual Band Antenna,Ã‚Â” see: ftp://ftp arnewsline org/quincy/News/news txt

New Web Site for ARISS-Brazil

ARISS Brazil recently formed a partnership with the internet portal DiÃƒÂ¡rio da ProduÃƒÂ§ÃƒÂ£o com to publicize ARISS activities in Brazil and South America To view the Web site, go to: http://diariodaproducao com/

[ANS thanks Carol, KB3LKI, for the above information]

/EX

In addition to regular membership, AMSAT offers membership in the President's Club Members of the President's Club, as sustaining donors to AMSAT Project Funds, will be eligible to receive additional benefits Application forms are available from the AMSAT Office

73, This week's ANS Editor, Lee McLamb, KU4OS ku4os at amsat dot org

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