UPDATE:
The IHU crashes each eclipse, erasing the software needed to operate the repeater automatically. At this time the command team is turning the repeater on and off during some US passes, mainly in the afternoon, and only as available. The repeater is open to all when this happens. The uplink is now 145.880, and the downlink is 435.150. We are working on trying to automate this.
73, Drew KO4MA
AO-51 Partial Operation Restored
AMSAT-NA VP Operations, Drew Glasbrenner, KO4MA reports that partial operation has been restored to AO-51.
Because the Integrated Housekeeping (IHU) computer crashes during each eclipse turning AO-51 ON requires a manually sent series of commands from a control station to reload a small housekeeping program stored on the satellite from ROM, then turning the repeater on, setting the modulation level and turning the RF power down.
At present, this re-start sequence is being done on afternoon passes over North America when the satellite's solar panels are being illuminated by sunlight and it is in range of an available control station. AO-51 is being left enabled after the North American afternoon passes so stations in Asia may hear it active still on the descending morning passes there.
The crashes prevent Whole Orbit Data from being collected for analysis on the ground. Analysis of live telemetry indicates that one of the Ni-Cd battery cells has failed. Further study is still in progress.
Drew concluded, "Thanks for all the donations for Fox and ARISSat-1 over the last week! If you haven't yet donated, drop by the AMSAT web page, or call Martha at 1-888-322-6728 today and help us get Fox in space."
AO-51 Partial Operation Restored
AMSAT-NA VP Operations, Drew Glasbrenner, KO4MA reports that partial operation has been restored to AO-51.
Because the Integrated Housekeeping (IHU) computer crashes during each eclipse turning AO-51 ON requires a manually sent series of commands from a control station to reload a small housekeeping program stored on the satellite from ROM, then turning the repeater on, setting the modulation level and turning the RF power down.
At present, this re-start sequence is being done on afternoon passes over North America when the satellite's solar panels are being illuminated by sunlight and it is in range of an available control station. AO-51 is being left enabled after the North American afternoon passes so stations in Asia may hear it active still on the descending morning passes there.
The crashes prevent Whole Orbit Data from being collected for analysis on the ground. Analysis of live telemetry indicates that one of the Ni-Cd battery cells has failed. Further study is still in progress.
Drew concluded, "Thanks for all the donations for Fox and ARISSat-1 over the last week! If you haven't yet donated, drop by http://www.amsat.org, or call Martha at 1-888-322-6728 today and help us get Fox in space."
Keep up with the latest AO-51 Control Team News on-line at:
http://www.amsat.org/amsat-new/echo/CTNews.php
Command Team and Operations Group AO-51 News
UPDATE:
After much trial and error, we have found a "sweet spot" where AO-51 will stay operational through eclipse for the time being. Cell 3 is a dead short, and cell 2 now goes to zero in eclipse also. It's amazing the satellite will operate on 2/3rds the designed voltage input!
How long AO-51 can be kept operational is anyone's guess. By the end of this year, eclipses will be headed for 30 minutes long. It is unlikely it will continue to operate as-is at that point. Enjoy while you can.
Uplink is 145.880, no PL
Downlink is 435.150 at about 1 watt
Please support AMSAT-NA and the other AMSAT groups around the world, and help us get new satellites into orbit. Projects like Fox, FunCube, P3E, and Kiwisat need your financial support to keep our amateur satellite fleet flying.
73, Drew KO4MA
AMSAT-NA VP Operations
Weekly Satellite Report
October 16, 2011
Currently we are running the repeater on 435.150 down, 145.880 up. Somehow, we've found a sweet spot where it will run through eclipse, despite 2 of the 6 cells in the battery being shorted. Enjoy it while it lasts!
May 6, 2011
We are having a difficult time trying to restore AO-51 to operation. Currently, the satellite will not retain the upload of the flight software across eclipse. The batteries are in very poor condition. We have a few more things to try, but with eclipses peaking around July at ~27 minutes, the long term situation is grim. There is a brief period around November where eclipses are as short as 16 minutes, but past that it is a long climb to 30 minutes or longer eclipses for many years. We have no expected "return to service" date. If you have 9k6 digital capability, you can listen in on our attempts at recovery on 435.150 on many passes over the US.
Please support AMSAT-NA and the other AMSAT groups around the world, and help us get new satellites into orbit. Projects like Fox, FunCube, P3E, and Kiwisat need your financial support to keep our amateur satellite fleet flying.
73, Drew KO4MA
AMSAT-NA VP Operations
2011年9月11日 戶外上下鏈ao51成功
2011年10月22日 戶外上下鏈AO51成功
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野外經AO51衛星
通聯泰國HS3ANP
野外經AO51衛星
通聯泰國HS3ANP
