ACE Weekly 04/06/2007 - 04/12/2007

All ACE spacecraft subsystems are performing nominally.

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Orbit/Attitude:

No attitude maneuvers were completed this week.  The next attitude maneuver
is scheduled for Thursday, 04/19/2007.

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OCRs:

None

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Activities:

Quarterly security scans of the ground system were performed Thursday, April
12, 2007.

RIONET
* Security scan for String 2 was completed in preparation for transfer to
RIONet.  Vulnerabilities are being resolved and a rescan will be scheduled.
* String 2 conversion is still targeted for April 18, 2007.

Space Link Extension (SLE) - ACE SLE version 2.1 was delivered to the
Library on April 28, 2006.  Installation in the ACE MOC will not occur until
after the MOC is converted to the RIONET.

An evaluation is ongoing to replace the TPOCC mission software and
incorporate ACE operations into a multi-mission ops center.  A decision
between L3 INCNG and ITOS mission software is expected by the end of April.

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Anomalies:

Update on AR#S07-0002  SWEPAM-E Current Spike
Last week's report incorrectly stated that the SWEPAM-E shutoff autonomy bin
was set for 90 consecutive occurrences above 0.113Amps.  The shutoff bin
will actually execute after 3 consecutive occurrences.  The values are
checked once per second.

DOY 102  04/11/2007  S-ACE-0165  G07-0024  Limits not checked
The ACE ground system database has switch mnemonics for limit checks.
Switch mnemonics allow a parameter to be limit checked only if the
subsystem/instrument is on (e.g. ZZSWPEPWR = 1).  The original database,
however, used the mnemonic name from Integration and Test (e.g. ZZALARME =
1).  Since these mnemonics are not valid (always =0), the limits are not
checked.  Analysis of life-of-mission data is being performed to determine
previous range of values.  Reports will be given to instrument teams to
re-evaluate limits for instruments that have been reconfigured during the
mission.
IMPACT:  The affected instruments are SWICS, SWIMS, SEPICA, SWEPAM and
ULEIS.  The problem does not affect CRIS, SIS, EPAM or MAG.  97 delta limits
and 116 red/yellow limits not checked since launch.

DOY 103  04/12/2007  S-ACE-0166  G07-0025  TAPS Cross-Byte Decom Problem
The TAPS trending software is incorrectly extracting parameters that have
the following conditions: 1) does not start at bit 0, 2) extends to the next
byte, 3) and is 8 bits or less.  For example, LAST_AUTBIN_EXE starts at bit
2 and covers 8 bits (xxXXXXXX XXxxxxxx), the actual value for
LAST_AUTBIN_EXE is 255 (11111111), but TAPS incorrectly reads the value as
252 (11111100) where the 2 bits from the 2nd byte are incorrectly set to 0.
CDSID#00023375
IMPACT:  TAPS trending does not correctly extract the following parameters
LAST_AUTBIN_EXE, SSSRELAYS, SSS2KASET, SSS2KBSET, SSS2KCSET, SSSM5LIM,
SSSM15LIM, SSS30KSET, and SSS75SET.