Monday, July 11, 2011
AO-51 operations update
AMSAT Vice-President of Operations Drew Glasbrenner, KO4MA, provided the latest details in AMSAT's work to keep the amateur radio satellite AO-51 operational for as long as possible.
Drew wrote, "Keeping AO-51 operating requires the US command team routinely restarting the satellite, and tweaking the power settings to find a combination of operating parameters to get it through eclipse. Currently one of the 6 battery cells onboard is shorted, and another is in really poor shape."
Continuing, Drew explains, "The onboard computer was crashing each orbit because of low voltage when the solar cells were no longer receiving illumination and the satellite relies entirely on its internal battery power. Through experimentation the Command Team seems to have found a balance point where it will sometimes go up to two days before crashing."
Each time the computer crashes the Command Team has to restart it using the housekeeping software onboard in ROM. The firmware code has a limited functionality compared to the normal flight software which we would upload from the ground over a few days time. However the eclipses and battery problem were causing a crash before the upload can complete.
Drew concludes, "With lots of luck we will be able to continue to
limp along. How long is anyone's guess. I'd encourage you to use AO-51 while it's available, and to financially support new satellite programs like Kiwisat, Funcube, and Fox when you can."
Uplink: 145.880 MHz, no tone.
Downlink: 435.150 MHz
The repeater is open to all when the satellite is operational.
Keep up with the latest AO-51 Control Team News on-line at:
http://www.amsat.org/amsat-new/echo/CTNews.php
Drew Glasbrenner, KO4MA
AMSAT-NA VP Operations
From http://www.southgatearc.org/index.htm
Drew wrote, "Keeping AO-51 operating requires the US command team routinely restarting the satellite, and tweaking the power settings to find a combination of operating parameters to get it through eclipse. Currently one of the 6 battery cells onboard is shorted, and another is in really poor shape."
Continuing, Drew explains, "The onboard computer was crashing each orbit because of low voltage when the solar cells were no longer receiving illumination and the satellite relies entirely on its internal battery power. Through experimentation the Command Team seems to have found a balance point where it will sometimes go up to two days before crashing."
Each time the computer crashes the Command Team has to restart it using the housekeeping software onboard in ROM. The firmware code has a limited functionality compared to the normal flight software which we would upload from the ground over a few days time. However the eclipses and battery problem were causing a crash before the upload can complete.
Drew concludes, "With lots of luck we will be able to continue to
limp along. How long is anyone's guess. I'd encourage you to use AO-51 while it's available, and to financially support new satellite programs like Kiwisat, Funcube, and Fox when you can."
Uplink: 145.880 MHz, no tone.
Downlink: 435.150 MHz
The repeater is open to all when the satellite is operational.
Keep up with the latest AO-51 Control Team News on-line at:
http://www.amsat.org/amsat-new/echo/CTNews.php
Drew Glasbrenner, KO4MA
AMSAT-NA VP Operations
From http://www.southgatearc.org/index.htm
Sunday, July 3, 2011
Saturday, June 4, 2011
Listening to HF via on the Web
A WebSDR is a Software-Defined Radio receiver connected to the Internet, allowing many users to listen and tune it simultaneously.
SDR technology makes it possible for all listeners to tune independently, and thus listen to different signals; this is in contrast to the older Internet connected receivers that can only be tuned by one person.
The WebSDR.org site lists Internet SDR receivers all over the world that you can use. If you ever wondered what your 40m signal sounds like in Atlanta then tune in one of the SDR's listed at http://www.websdr.org/
From http://www.southgatearc.org/index.htm
SDR technology makes it possible for all listeners to tune independently, and thus listen to different signals; this is in contrast to the older Internet connected receivers that can only be tuned by one person.
The WebSDR.org site lists Internet SDR receivers all over the world that you can use. If you ever wondered what your 40m signal sounds like in Atlanta then tune in one of the SDR's listed at http://www.websdr.org/
From http://www.southgatearc.org/index.htm
Wednesday, June 1, 2011
The Sun is becoming more active again
After an approximate two week slumber the sun is becoming active once again.
The daily solar flux index rose to 91.0 on Friday May 27, 2011 after a minimum of 79.7 on Wednesday May 25, 2011. The daily sunspot number rose to 65 on Friday May 27, 2011 after a minimum of 23 on Tuesday May 24, 2011.
The number of sunspot groups is rising again with five visible numbered groups and one visible but as of yet un-numbered on Friday May 27, 2011.
New sunspot group #11226 located at S18E74 is growing rapidly in size and magnetic complexity and contains a twisted beta-gamma magnetic signature capable of producing M class solar flare and isolated X class solar flares. In the past 24 hour period the sunspot group has released five C class solar flares.
Recurrent transequatorial coronal hole #450 was in geo-effective (earth facing) position on May 24-25, 2011 and has impacted Earth's magnetic field in a negative manner with a maximum Kp of 6 (moderate geomagnetic storming conditions) and a maximum solar wind of ~550 (km/s).
73 & GUD DX,
Thomas F. Giella, NZ4O
Lakeland, FL, USA
From http://www.southgatearc.org/index.htm
The daily solar flux index rose to 91.0 on Friday May 27, 2011 after a minimum of 79.7 on Wednesday May 25, 2011. The daily sunspot number rose to 65 on Friday May 27, 2011 after a minimum of 23 on Tuesday May 24, 2011.
The number of sunspot groups is rising again with five visible numbered groups and one visible but as of yet un-numbered on Friday May 27, 2011.
New sunspot group #11226 located at S18E74 is growing rapidly in size and magnetic complexity and contains a twisted beta-gamma magnetic signature capable of producing M class solar flare and isolated X class solar flares. In the past 24 hour period the sunspot group has released five C class solar flares.
Recurrent transequatorial coronal hole #450 was in geo-effective (earth facing) position on May 24-25, 2011 and has impacted Earth's magnetic field in a negative manner with a maximum Kp of 6 (moderate geomagnetic storming conditions) and a maximum solar wind of ~550 (km/s).
73 & GUD DX,
Thomas F. Giella, NZ4O
Lakeland, FL, USA
From http://www.southgatearc.org/index.htm
Saturday, May 7, 2011
AO-51 recovery attempts continue
AMSAT-NA VP Operations, Drew KO4MA, provides an update on the work to recover the Amateur Radio satellite AO-51.
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.
Drew, KO4MA
AMSAT-NA VP Operations
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.
Drew, KO4MA
AMSAT-NA VP Operations
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