ACE Weekly 01/19/2007 - 01/25/2007 All ACE spacecraft subsystems are performing nominally. ============================================================================ 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. ============================================================================ OCRs: None Step 7 of OCR SEP-110 to turn off internal stimulation still needs to be scheduled. ============================================================================ 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. ============================================================================ 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.