ESA Cassini-Huygens Status Report, 07-12-2004

Second Battery Depassivation

The second run of the Huygens Battery Depassivation sequence was
successfully executed on 5 December.

Initial indications are that the data looks exactly the same as the first
depassivation from 19 September, with all Probe systems exhibiting nominal
behaviour.

The depassivation sequence, which was run in “Flight Checkout Suspend” mode
and Pre-T0, started at 06:00:00 (SCET/UTC) and lasted for 35 minutes, after
which there was a 5 minute pause before the Probe Saving sequence started.
This lasted for 8 minutes and was run to ensure that no battery remained
connected to the Probe power bus.

Each battery exhibited essentially the same behaviour during each of the 5
minute depassivation periods, with voltages starting at ~65V and slowly
increasing to ~70V. Measurements on the bus side showed battery currents of
~1.9A with a similar value being measured from the Cassini line, which
indicated an equal sharing of the bus load between battery and Cassini. Bus
voltage was steady at 28V.