AO-40 Recovery Continues

From the http://www.amsat-dl.org/journal/adlj-p 3d.htm...


AMSAT-DL Vice President Peter Guelzow, DB2OS, gave a summary of recent command team actions regarding AO-40:





"The recovery efforts of AO-40 continue, mainly centered around housekeeping tasks designed to improve and stabilize the systems onboard the satellite. In addition, new software routines were successfully loaded that restored all Battery Charge Regulator functions and have resulted in a positive power budget with happy batteries. The command team is also pleased to report that the AO-40 Flight Software is now completely re-loaded (with the exception of D-block programming and WOD routines which will be done later).


Command station G3RUH (James Miller) reported that commanding AO-40 on L-band frequencies was fairly easy (~250 Weirpc only at 50° Squint!), thus it appears the L-band receiver seems to be work nominally.


A quick look at received telemetry instrumentation shows Helium pressure at essentially where it was following the first 400-N motor burn. Also, it appears that a few temperature and current sensors either failed and/or are showing incorrect values. The onboard sun sensors appear to be fine and are showing a solar angle that is near our predictions. The received spin rate telemetry is not accurate when compared to the actual spin as measured by the doppler wobbling of the S-band beacon. There appears to be a substantial spin increase. Clearly, more time is needed to analyze and understand what has happened here.


The good news is that the spacecraft is now fully under control. During the next several days additional software will be loaded and the various uplinks will be verified before a command is sent to turn on the 2-meter again."



According to S-Band observations best MAs to get reasonable signals from AO-40 S2-MB (around 2401.325 MHz +/- Doppler) are from MA 16 to MA 32.



In "Spacefligt Now" you can find a brief article about AO-40's recovery: spaceflightnow.com/news/n0012/27ao40/"