JARL report about FO-29 (Fuji-3) status and operation, 7 Aug 2007

The inside impedance of battery in FO-29 (Fuji-3) are rising now extremely by deterioration at time. According to the telemetry data and the eclipse rate of the satellite main body (the rate that a day is not), 25 minutes are supposed with a limit as for the analog battery system use. Because the eclipse rate of current FO-29 (Fuji-3) is about 30%, the power supply of the relay with the battery cannot serve a period of the eclipse.

And the malfunction occurs in the part of the electricity control system. The malfunction to become the problem in use in particular is UVC which is an automatic function about the electricity management. When the satellite is in the eclipse, and the light of the sun is not the solar battery, the transmitter becomes OFF by UVC. It is designed afterwards so that an analog system transmitter becomes ON automatically when the terminal voltages of the battery exceed the rated value after the light of the sun is the solar battery. However, it is likely that malfunction occurs for this function, and the terminal voltage cannot turn on a transmitter even if it exceed the rated value unless we send a command from the ground.

The eclipse rate of FO-29 (Fuji-3) will rise in future and rises to 34% in March 2008 and comes over a peak of the eclipse rate. When it goes over this peak, the eclipse rates decrease slowly, and it is 20% in August 2009, and it is all sunshine (the period when the sun continues being) in February 2010.

Because we follow for about 8 months, as for all sunshine, it seems that we can apply the analog system relay consecutively for this period.

http://www.ne.jp/asahi/hamradio/je9pel/fo29sta3.htm#3

--------------------------------------------- Name: Mineo Wakita / JE9PEL, JAMSAT member Mail: ei7m-wkt@asahi-net.or.jp URL : http://www.ne.jp/asahi/hamradio/je9pel/ QTH : Yokohama Japan, GL:pm95tj Date: Aug 10, 2007 ---------------------------------------------