ACE Weekly 08/25/2010 - 08/31/2010

All ACE spacecraft subsystems are performing nominally.

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Orbit/Attitude:

No maneuvers were completed this week.  The next attitude maneuver is
scheduled for Tuesday 09/07/2010.

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OCRs:

None

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Activities:

Data Capture:  100%  DOY 234-241 2010

DOY 242 08/30/2010  DSN SPS/TTC Project Interface Test (PIT)
DSN requested 2 Project Interface Tests for the upgrade (v9.1.4 ->
v10.1) of the DSN Tracking, Telemetry & Command (TTC) system.  The first
PIT on DOY 235 had used a test SLE CMD Provider.  The second PIT on DOY
242 used both the test SLE TLM Provider and the test SLE CMD Provider.
At the low data-rate (498bps), telemetry to the MMOC was delayed and
came in a single burst.  After switching to the high data-rate
(87648bps), only 20% of the realtime data arrived in the MMOC and none
of the playback data.  Also, telemetry from the test SLE TLM Provider
was not saved by DSN's Central Data Recorder.  50 minutes into the PIT,
DSN switched back to the operational SLE TLM Provider and all telemetry
was received in the MMOC.  The FOT requested staying with the
operational SLE TLM Provider until the last 30 minutes of the PIT.  At
that time, the spacecraft was switched back to the low data-rate, and
the DSN engineers analyzed the equipment while telemetry arrived in the
MMOC in bursts every 5 minutes.  The data from the first 50 minutes of
the pass was redumped on the following pass.

Background Information
	DSN occasionally requests that the missions take part in PITs
(Project Interface Test) and Demos.  DSN asks that the data during the
PITs and Demos be labeled "decommitted".  With the limited DSN antenna
time and reduced FOT staff, however, we have been using regular tracking
passes for PITs and Demos.  If the PIT or Demo is unsuccessful, NOAA
would lose 3.5 hours of real-time data and the spacecraft's SSR would
eventually fill-up and switch to the other SSR (resulting in a minimal
30 second gap).
	For the vast majority of DSN PITs and Demos, the problems have
been minimal and did not impact data.  But the PIT on Monday 08/30/2010
had more problems.  The loss of data to NOAA and the missing playback
data were expected possibilities.  The FOT had minimally staffed the PIT
and let the automation software run the pass.  However, DSN had
requested that the FOT switch between the test and operations SLE TLM
providers.  This was more effort than the FOT had available and the FOT
requested that DSN stay with the operational SLE TLM provider and make
one last switch to the test SLE TLM provider in the last 30 minutes of
the PIT.
	With the limited DSN antenna time and reduced FOT staff, PITs
and Demos will continue to be taken as tracking passes with the MMOC
automation software.

	
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Anomalies:

DOY 237  08/25/2010  S-ACE-0522  G10-0040 ITOS tm_controller
ITOS was unable to process telemetry due to a "timeout reading from
tm_controller".  ITOS was restarted before beginning of track.  This
problem occurs approximately once every 2 weeks.  DR CDSID#00027515 has
been submitted and the ITOS developers expect this to be fixed in the
next release of ITOS.
IMPACT:  Manual intervention required.  No delay in activities.

DOY 237  08/25/2010  S-ACE-0523  S10-0007  Increase in SBE_CT_B
SSR B Single Bit Error Count (SBE_CT_B) increased from 6839 to 7339
since last checked on DOY 231 (08/19/2010).  SBE_CT is tracked as a
measure of SSR health.
IMPACT:  Minimal.  Single Bit Errors are automatically corrected by the
SSR.  No non-correctable errors (Hard Single Bit Errors & Double Bit
Errors) have occurred throughout the mission.

	       SBE_CT_A  SBE_CT_B
	1999   15
	2000
	2001
	2002
	2003   270       286
	2004             858
	2005
	2006             2118
	2007   510       3238
	2008             4533
	2009   525       6839
	2010   780       7339

DOY 235  08/23/2010  S-ACE-0524  S10-0041  Missing 0158 Monitor Data
NISN (NASA Integrated Services Network) stopped forwarding DSN's 0158
Monitor Data to the MMOC and SOHO MOC on Monday 08/23/2010 2014z.  The
FOT noticed the missing data on Thursday 08/26/2010 and contacted NISN.
NISN resumed forwarding the monitor data.
IMPACT:  DSN's Monitor Data is not used by the automation software, but
it is used when trouble-shooting problems with DSN.  For example, it was
used regularly when ACE and WIND had transitioned to the MMOC for
trouble-shooting SLE connection problems.

DOY 240  08/28/2010  S-ACE-0525  S10-0042  MUS CMD process terminated
The MMOC SLE (MUS) cmd process (ace-d24-cmd) terminated unexpectedly 2
minutes after beginning of track.  The FOT manually restarted the MUS
CMD process.  This last occurred on 05/25/2010 (AR#G10-0027).
IMPACT:  Manual intervention required.  Activities delayed 15 minutes.

DOY 242  08/30/2010  S-ACE-0526  S10-0043  Problems with TTC V10.1 PIT
There were problems using the test SLE TLM Provider during the TTC PIT
(Project Interface Test).  At low-rate (498bps) telemetry was received
in bursts every 5 minutes.  At hi-rate (87648bps), only 20% of the
realtime data arrived in the MMOC and none of the playback data.  50
minutes into the PIT, DSN switched back to the operational SLE TLM
Provider and all telemetry was received in the MMOC.  Telemetry from the
test SLE TLM Provider was not saved by DSN's Central Data Recorder.  DSN
does not enter DRs for PITs since the data is considered "decommitted".
IMPACT:  NOAA was unable to process ~60 minutes of realtime data (50
minutes on test SLE provider + 10 minutes of MMOC reconfiguration).
Playback data during this time was redumped on the following pass.