Solar Eclipse 2015

Solar Eclipse and AO-73 on 20-03-2015 starts 07:41 UTC and ends at 11:50 UTC.


Coming Friday there will be a solar eclipse and during this eclipse there are in my case 3 AO-73 (FUNcube-1) passes that go through this region. Therefore it is interesting to see how this phenomenon influences the satellite.

For my location (JO21) the following times are interesting (Times in CEST = UTC+1)

Solar Eclipse path 20-03-2015

First AO-73 pass in this periode starts 09:21 CEST
Second AO-73 pass in this periode starts 10:57 CEST (best opportunity)
Third AO-73 pass in this periode starts 12:33 CEST

When you look closely to the below image, taken from Oribitron you can see that Sun and Moon fall over each other.


I will listen for the AO-73 beacon during these three passes and upload the data to the FUNcube Warehouse.

NASA | Shadow of the Moon. The Moon’s shadow will create a total solar eclipse. This video presents several visualizations of what this shadow would look like from space, and highlights the areas of the world in the path of the umbra and penumbra.

Longer Eclipse Periods Affecting AO-51

Amsat Oscar AO-51AO-51 Command Stations report that the seven year old spacecraft is now shutting down its transmitter after losing sunlight on its solar panels during eclipse periods. Two of the six battery cells are now dead. Since July 31, 2010 AO-51 has maintained continuous and stable operations due to careful tuning of its power settings.

The AO-51 Operations Team reported on November 25 that the on-board computer (IHU) crashed between 1815 and 1945Z due to low voltage. This happened after a few days of intermittent and unpredictable operation.

AO-51 Control Operators Mark Hammond, N8MH and Drew Glasbrenner, KO4MA reset the satellite and started the repeater back up around ~2030Z. Satellite operation was set to the following:

Uplink: 145.880, no PL tone required
Downlink: 435.150 at about 300 milliwatts

Satellite EclipseDrew reported that telemetry data showed the battery voltage was low, around 4.9v, with cell 1 less than 1 volt. The impending third cell failure will likely end continuing operations, particularly if it fails shorted as the others have. At present there remains little margin as the operations team has observed the transmitters cutting off around 4.7 to 4.6 volts prior to the last reset, in eclipse.

Please submit your AO-51 reports to the OSCAR Status Web Page: The command stations monitor this for changes in the operation. While worldwide participation is good, more reports from US operators are appreciated.

Eclipse periods, which are expected to reach 30 minutes by the end of 2011, are causing AO-51 to shut itself OFF due to low voltage.

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.

You can keep up with the latest AO-51 Command Team news at:

Source: Amsat NA

FO-29 Eclipse Undervoltage Stops Operation

FO-29Information has been received that the FO-29 analog repeater is currently off the air. The eclipse periods have increased to the point exceeding 27% shadowing which causes an undervoltage fault to shut down the satellite.

The FO-29 control station sent commands to reactivate the satellite during daytime passes over Japan between October 8-10. Also at the present time the control station was experiencing computer hardware problems which slowed progress.

[Thanks Mineo, JE9PEL, for the above information]