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The AO-40 command team has established a routine of trying to cycle the main battery off (aux. battery on) and then the S2 Tx ON every orbit, using simple machine codes. Following this, the sequence to disconnect all transmitters is sent, to protect them from low voltage. If we have approximately 10 volts on the main buss, then these commands should be making it through, but the S2 transmitter was not designed to run below 20 volts and is not coming on. The battery relay has been tested in the AMSAT lab, where a duplicate exists, and it will cycle reliably at 12 volts, but not lower. If we have less than 10 volts, then the commands will not be received because the IHU-1 and/or command receivers are insufficiently powered. Either way, the IHU-1 is not currently running IPS. The machine code commands only function in reset mode. We assume that we currently have less than 12 volts and that either the IHU-1 and relay are not functional (<10 volts) or the relay isn't functional (<12 volts), because cycling the relay should get us out of this situation by disconnecting the main battery.
With regard to the stability of the attitude/spin, this will not be a concern for a very long time. We are currently rotating at 3.5 RPM. The spin decay rate is extremely slow. It will take approximately 4 years to drop this to 3.0 RPM. We can magnetorque at speeds as low as 1.5 RPM. The mystery effect will decrease ALON approximately 11.5 degrees/week. It does not affect ALAT, though ALAT will change slightly as the orbit precesses.
The main batteries consist of three packs housed in sheet aluminum cases and bolted to the radial braces between panels 1/6, 2/3 and 4/5. The cells within the packs have threaded metal binding posts and the cells are connected by thick metal straps with strain relief "U's" in them. The pack at 2/3 consists of 7 cells and is the negative end of the chain. The pack at 1/6 consists of 6 cells and is in the middle of the chain. The pack at 4/5 consists of 7 cells and is at the positive end of the chain. The main battery pack at 1/6 is the closest battery to the "flaky" heat pipe thermistor, though it is located "below" this heat pipe near the omni end of the spacecraft. Main battery packs 4/5 and 1/6 lost their thermistors during the 400N incident. Whether this was due to trauma to the battery or damage to the cabling is unknown. If a short to ground occurred in the 1/6 battery pack it would pull the cells on the negative side of the short in this pack to zero, as well as all cells in the 2/3 pack. Depending on the location of the short and the status of the cells in pack 4/5, this could pull the main buss voltage to half normal (14 volts) or even 10 volts or below. <conjecture> A short at this location might have generated enough localized heat (or even some hot metal spatter) to damage the thermistor on the flaky heatpipe or, more likely, its wiring. This is appealing because it would represent a single point failure, rather than a failure cascade. One piece of evidence that doesn't clearly fit with this theory is that the cells in pack 2/3, the one main battery pack that still has a thermistor temperature sensor, do not appear to get warm following the voltage drop. We do not know how much capacity remained in these cells. It is possible they contained relatively little energy. </conjecture>
As several of you indicated, we are in a waiting game for the main battery to develop one "open" cell.
[ANS thanks Stacey, W4SM, for the above information]
Many thanks to all who participated in AMSAT-NA's 32nd annual Straight Key Night on OSCAR, 1 January 2004. With only AO-7 and FO-29 available for use this year, the activity level was down from the record high participation of 2003, but as always a good time was had by all who took part.
Our Best Fist winners for 2004, each nominated by someone he worked, are:
Richard Limebear, G3RWL
Cliff Buttschardt, K7RR
Keith O'Brien, N4ZQ
Al Ozias, N7EQF
Al Tribble, W3STW
Congratulations to all. See you all next year!
[ANS thanks Ray, W2RS, for the above information]
On January 28, The King's School in Canterbury, England experienced a successful ARISS contact with Mike Foale, KB5UAC. Twelve questions were asked and answered. Students and teachers as well as the Lord Mayor of Canterbury, the school's dignitaries, the RSGB and AMSAT UK representatives were in the audience. Meridian TV, BBC TV, BBC Radio Kent, Invicta Radio, and the Kent Gazette covered the contact, and broadcast the event in their main news. The BBC World Service and the Press Association asked for information and transcripts.
An ARISS contact has also been scheduled for James Bay Elementary School in Houston, Texas. This contact will take place on February 4.
The ARISS International Team held a teleconference on Tuesday, January 20. Agenda items discussed included the next face-to-face meeting to be held in the Netherlands in March, 2004, and the Expedition 9 crew change which may adversely affect school contacts if Leroy Chiao is not licensed before his launch. Also discussed was a Packet User Service Agreement, which would provide ground based ham radio operators with guidelines on how to use the ISS packet radio equipment.
Astronaut Leroy Chiao, who will be replacing William McArthur Jr., KC5ACR, as commander of the Expedition 9 crew on the ISS, has expressed interest in obtaining his amateur radio license. He will try to get through training prior to the next Soyuz launch in April. His licensure and training are critical to the continuation of the ARISS school contacts during the Expedition 9 increment.
The ARISS team has been unable to schedule ISS Ham engineering passes for the Kenwood radio system voice tests in early February due to the scheduled Progress 13P docking and unpacking. The team is currently looking at the weeks of February 16 - March 15 to schedule their tests. A procedure for the tests has been written and will be uplinked to Mike Foale in the near future.
ARISS Chairman Frank Bauer and other members of the ARISS team met at GSFC on Saturday, January 17. The team worked on getting the radio station, NN1SS, set up for the engineering passes.
[ANS thanks Carol Jackson for the above information]
An Oregon girl considered a year ago as the youngest General class licensee in the US now may be the country's youngest Amateur Extra ticket holder. Seven-year-old Mattie Clauson, AD7BL (ex-KD7TYN and ex-KD7SDF), of Roseburg passed her Extra examination January 14 during a Valley Amateur Radio Club ARRL-VEC volunteer examination session in Eugene. The FCC granted her new ticket and an Extra-appropriate call sign on January 20.
She announced her accomplishment in a message routed via the RS0ISS packet system on the International Space Station. "Looks like a future astronaut to me," Amateur Radio on the International Space Station (ARISS) Chairman Frank Bauer, KA3HDO, remarked after spotting the post.
Mattie says she'd at least like to talk with one of the ISS astronauts some day. She says she heard ISS Expedition 8 Commander Mike Foale, KB5UAC, on the air from NA1SS but was unable to make contact. She keeps listening, however. She's also a member of the ISS FanClub and enjoys digipeating through RS0ISS.
[ANS thanks the ARRL for the above information]
Link to the weekly report on satellite ...
ISS. RS-12. RS-13. RS-15. AO-7. AO-10. UO-11. UO-14. AO-16. LO-19. FO-20. UO-22. KO-23. KO-25. IO-26. AO-27. FO-29. GO-32. SO-33. PO-34. UO-36. AO-40. SO-41. SO-42. NO-44. NO-45. MO-46. AO-49. SO-50
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This week's AMSAT News Service bulletins were edited by AMSAT News Service Editor Lee McLamb, KU4OS, firstname.lastname@example.org