Oscar 40 har ftt ngot problem med batterierna s passbandet r avstngda just nu. Problemet undersks:
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On orbit 1486, the main battery voltage ran lower than expected. This was due in part to usage and high solar angle as mentioned previously, but even after the passbands were shut off automatically the voltages did not come
back up as expected, in spite of apparently positive battery charge currents. At the beginning of the eclipse on orbit 1486 at MA =225, the battery voltage rapidly dropped just below the S2 Tx cutoff voltage of 24.0
volts and the S2 Tx shut down. to protect the battery and IHU s. The eclipse ended at about MA=237, approx. 55 minutes later. We expect the S2 Tx to start back up as programmed at MA =2 (as I type this), though it has
been known to be balky before on restarts and could require manual cycling.
The command team is investigating this anomaly to determine if the main battery may have developed a single bad (shorted) cell or if there is a problem with the battery set voltage, solar array set voltages, or other
problem. Until we sort this out the passbands will be off for one or more orbits. If the battery charge or array set points are wrong, they can be changed. If we have one bad ( shorted ) cell we can reset charge/trigger points to account for this, and we have the completely redundant auxiliary battery, if needed. We hope to be able to work through this and correct things without too much down time.
We ll update you here as soon as we know more.
– –W4SM for the AO-40 Command Team
Klla: W4SM