ACE Weekly 02/03/05 - 02/10/05

All ACE spacecraft subsystems are performing nominally.

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Orbit/Attitude:

No maneuvers were executed this reporting period.  The next attitude
maneuver is scheduled for Friday 02/11/05.

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OCRs:

SEP-109 Planned for next week
Update the 2kVC setpoint to correspond to the current Fan 3 pressure.

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Ongoing Activities:

The Sun-Earth-Vehicle (SEV) angle will reach 1.435 deg on 02/21/05 (from
FDF).  DSN has had no problems acquiring the downlink for SEV angles greater
than 1 deg.  No problems are expected with the expanding Lissajous orbit.

The requirements review for SLE (Space Link Extension) implementation of ACE
commanding to DSN is underway.

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Extra Activities:

DOY 040 (02/09/05)  IPNoc Router upgrade completed with only a couple of ~2
minute TLM outages.  All data captured on CDR.

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Anomalies:

DOY 035 (02/04/05) ACE Anomaly S05-0007  SEPICA Fan 3 Pressure Drop
At 11:18:38z SSSPC3P began to lose pressure.  Yellow Low limit (raw=300)
violated at 11:20:38z.  Red Low limit (raw=245) violated at 11:29:39z.
SSSPC3P reached zero at 13:20:42z.  As a result of the pressure drop,
SSS2KCV, SSS2KI and SSS2KV were turned off at 11:42:15z.  SSSALARMS
transitioned from 6 to 14 at 11:42:51z.
IMPACT:  (from Mark Popecki) The Fan 3 pressure is now low, and the fan 3
anode voltage has been turned off by a pressure sensor. It may remain in
this state permanently, or the valve may open on its own, as it did in 1998.