ACE Weekly 11/12/04 - 11/18/04
All ACE spacecraft subsystems are performing nominally. No maneuvers were
executed this reporting period. The next attitude maneuver is scheduled
for 11/22/04.
============================================================================
Orbit Events:
From Craig Roberts (FDF):
The next ACE Solar Exclusion Zone transit has begun. ACE crossed the 4.75
deg mark inbound on 11/15/04, and will exit outbound by 12/09/04. As the
ACE Lissajous orbit transitioned to an opening pattern mid-summer, we are
now in an era where the Sun-ACE separation angle at closest approach will
be greater with each successive crossing (for the next couple of
years). This time the angular radius of closest approach (RCA) will be
0.83 degree (last time it was 0.31 deg (11/31/04)). More details below:
3.0 deg inbound: 11/20 02:17Z
2.0 deg inbound: 11/22 18:53Z
1.0 deg inbound 11/25 19:29Z
0.83 deg RCA 11/26 21:32Z
1.0 deg outbound 11/28 12:08Z
2.0 deg outbound 12/01 13:24Z
3.0 deg outbound 12/04 06:50Z
ACE will spend 2.7 days below 1.0 deg.
=====================================================================
OCRs Executed:
None
=====================================================================
Ongoing Activities:
TAPS:
- TAPS Release 4.3 was installed on the Prime System on 10/13/04.
-- FOT regression testing is in progress.
--- No problems to report.
----------------------------------------------------------------------------
Automation (ROBOTT):
- ROBOTTv0.9 delivered to String 1 on 09/27/03 (OCR GND_145).
-- Performing operations in "Auto" mode on String 1.
-- 13 DR fixes in this release.
--- 12 DRs have been verified by the FOT to date.
--- The last DR to be verified will require ROBOTT to be
observed over a period
of time to ensure no reoccurrence of the problem.
-- 13 DRs have been written against this release.
- Lights-out weekend operations started 11/13/04.
- ROBOTT FOT Test Summary Report ready for signature.
- ROBOTT System User's Guide (SUG) (signed) received from Developers.
============================================================================
Extra Spacecraft Activities:
DOY 04320 (11/15/04) Executed the procedure S_TLM_SECTIONS for SSR-B. THE
SBE_CT_B increased from 608 to 858. The SCRUB_ERR_CT_B remains at 0. The
last time S_TLM_SECTIONS was performed was on 09/22/04, the SBE_CT_B
increased from 286 to 608.
DOY 04321 (11/16/04) Execute the procedure S_TLM_SECTIONS for SSR-A. There
were no new SBE's for SSR-A.
=====================================================================
Anomalies:
DOY 04320 (11/15/04) ACE Anomaly S04-0015 - Increase in SSR B SBE Count
While scrolling through SSR B's 30 telemetry sections, the FOT noticed that
the SBE_CT_B had increased from 608 to 858. The Scrub Error Count
(SCRUB_ERR_CT_B) remains at 0. The last time S_TLM_SECTIONS was performed
was on 09/22/04, and the SBE_CT_B increased from 286 to 608. IMPACT: None.
DOY 04321 (11/16/04) ACE Anomaly G04-0133 - ROBOTT - FOT not receiving
ROBOTT pages
After being in the pass for 15 minutes (BOT 15:30), no pages had been
received from ROBOTT. At least two pages should have been
received. Password change occurred on DDS during the pass which may have
affected DDS operation. IMPACT: None. After noticing no email messages
from the DDS the FOT monitored the pass until such time email messages were
received again.
DOY 04321 (11/16/04) ACE Anomaly G04-0134 - GDS 34m (DSS-27) Telemetry Outage
At 17:09:45, the FOT lost telemetry from DSS-27. At 17:15, the TSS
informed the FOT of a communications problem. At 17:26:47, telemetry
resumed from DSS-27. IMPACT: Loss of data from 17:09:45 -17:26:47. Data
recovered via SSR redumps. DR# N102484
DOY 04321 (11/16/04) ACE Anomaly G04-0135 - No Data Available For System
Variable
While running the procedure s_tlm_sections.prc, the data server hadn't
updated the telemetry parameters before the procedure had reached the
telemetry checks. This last occurred on 2/29/04 (AR
G04-0017) IMPACT: Can cause problems if the GOTO statement was to the
incorrect line. If this problem happens at an IF statement and ROBOTT
gives it a GO, then the procedure may execute an inappropriate section of
the TSTOL procedure.
DOY 04323 (11/18/04) ACE Anomaly S04-0016 - STAR_BKGD_HIGH Configuration
Monitor Violation
At 19:03:29, STAR_BKGD_HIGH configmon violated. This occurred only once
during the pass. IMPACT: On Day 07027 there was a STAR_BKGD_HIGH RH limit
violation, however, this problem isn't similar (Ref. AR#SO4-0002). It is
believed that this anomaly is an erroneous value due to a processing
problem. AR#S04-0017 explains this in greater detail as this has occurred
with the STAR_L_TEMP configmon.
DOY 04323 (11/18/04) ACE Anomaly S04-0017 - STAR_LTEMP Erroneous Values
Over the life of the mission the nominal value of the star_ltemp (star lens
temperature) has been between 10-17 degrees. Occasionally the value drops
instantaneously to around -14 to -4 degrees. The FOT investigated why
this drop of about 20 degrees occurs. After analysis, the FOT determined
the negative temperatures occur when the spin rate of the spacecraft is
between 4.942 and 4.983 rpm. This trend has happened for the entire
mission. The last time this occurred was the last week in August
2004. IMPACT: Unknown at this time. The FOT will continue analysis and
monitoring of this event.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Glen A. Miller
ACE Flight Operations Observatory Engineer
Honeywell Technology Solutions Inc.
Goddard Space Flight Center
Building 14, Room W10A
Mail Stop 428.2
Greenbelt, MD 20771
Office: 301-286-7071
Pager: 800-425-3174
Fax: 301-286-1729
gamiller@pop500.gsfc.nasa.gov
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~