ACE Weekly 01/19/2007 - 01/25/2007

All ACE spacecraft subsystems are performing nominally.

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Orbit/Attitude:

	Type        Attitude       Attitude
	Date        01/19/2007     01/25/2007
	DOY         019 2007       025 2007
	Thrusters   2R 4R- 4R+     2R 4R- 4R+
	Duration    10:01 min      9:02 min
	Start       16:33:26z      16:29:51z
	Stop        16:43:27z      16:38:53z
	StartHGA    -4.28 deg      -2.98 deg
	StopHGA      5.51 deg       5.68 deg
	Firing      51 pulses      46 pulses
	FinalSCMass 1393.189lbs    1393.033lbs

The next attitude maneuver is scheduled for Thursday, 02/01/2007.

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OCRs:

None

Step 7 of OCR SEP-110 to turn off internal stimulation still needs to be
scheduled.

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Activities:

DOY 019 (01/19/2007) - SSR A Telemetry Sections downlinked.  No new Single
Bit Errors (correctable) found.  No non-correctable errors (Hard Single Bit
Errors & Double Bit Errors) have occurred throughout the mission.

DOY 022 (01/22/2007) - 2QFY07 security scan completed.

RIONET - Testing and configuration of String 3 continues.
* FDF is now providing all of their data files on the FDF product so that
they are available to the RIONet.  FDF will also provide their data files to
the Closed IONet strings until the transition to RIONet is complete.
* DSN CDR download test will occur Wednesday January 31, 2007.  JPL
personnel, IPNOC, FOT, and SysAdmins will be online for the test.
* The backup GMUG will be tested Tuesday January 30, 2007.  C/D Manager,
Comm Manager, FOT, and JPL personnel will be online for the test.

ROBOTT
* ROBOTT has not had any issues downloading the schedules from SPS, with one
exception.  We have asked DSN to check if their process might cause the
schedule version number to be incremented before the schedule changes are
made.
* Testing and configuration of WINDDS as a backup data distribution server
will start next week.
* The ROBOTT developer has started working on the patches to allow ROBOTT to
work with the RIONet.

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.

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Anomalies:

DOY 020  01/20/2007  S-ACE-0150  G07-0011  DSS-46 Incorrectly Configured
After spacecraft switched to high-rate, DSS-46 was no longer forwarding data
to the ACE MOC.  TCP1 CH2 was configured to the default "Complete Latency"
(data to CDR only).  TCP1 CH1 was configured to "Low Latency" (data to
CDR+MOC), but was not enabled.  The problem took 2.5 hours due to several
issues; unattended weekend support, paging service problems for 30 minutes,
initial reports that DSS-46 was sending high-rate data and FOT travel to the
ACE MOC.  There was no additional DSN time to complete the SSR playback.
DOY 021 was configured to a non-ranging support which added 15 minutes to
the next pass.
IMPACT:  Data loss for DOY 020 20:33:04-22:55:47z (duration 2:22:44).  By
chance, this gap corresponds to the 2.5 hours during which DSN's CDR was
recording ADC data.  ADC includes MAG, EPAM, CRIS, SIS and SWEPAM-I, but not
SWEPAM-E, ULEIS, SEPICA, SWIMS and SWICS.


Background Information
Problems such as this have recently resulted in data loss since available
DSN time is limited.  Here are a few of the reasons we have had problems
acquiring additional DSN time.

* DSN eliminated DSS-16 on February 1, 2006 which reduced the number of
antennas we use from 7 to 6.
* In the winter months, our viewperiods from antennas in the northern
hemisphere are shorter.  Since 4 of the 6 antennas are in the northern
hemisphere (Madrid Spain and Goldstone California), our overall available
time is reduced.
* Mars has been on the opposite end of the solar system, so the viewperiods
for the Mars missions (MRO, MEX, M01O, etc) are at the same time as the L1
missions (SOHO, WIND, ACE).
* DSN maintenance and mission launches cause some weeks to be tighter than
others.  For instance, DSS-27 was down for Wheel Replacement from DOY 018 to
DOY 022.

As we approach summer and as Mars moves around, we should have more time
available.  But the general trend seems to be that there is less available
time as more missions use DSN.