ACE Weekly 09/14/2007 - 09/20/2007 All ACE spacecraft subsystems are performing nominally. ============================================================================ Orbit/Attitude: Type Attitude Date 09/20/2007 DOY 263 2007 Thrusters 2R 4R+ 4R- Duration 12:19 min Start 19:42:50z Stop 19:55:09z HGAStart -7.48deg HGAStop +6.70deg SunStart 9.24deg SunStop 14.90deg Nutation 0.24deg Firing 63 pulses FuelUsed 0.2081lbs FuelRemain 154.2232lbs FinalSCMass 1388.483lbs The next attitude maneuver is scheduled for Monday, 10/08/2007. Note, sun angle and post-maneuver nutation have been added to the maneuver summary. The nutation is the half angle. For example, the post-maneuver sun angle varied between 14.66 and 15.14 degrees and the antenna angle (HGA) varied between 6.46 and 6.94 degrees. The nutation period is 8 seconds ... two-thirds of the spin period. ============================================================================ OCRs: None ============================================================================ Activities: Closed IONet cables were removed on Monday 09/17/2007. ACE had transitioned from the Closed IONet to the Restricted IONet back in July 2007. The DOY 260 pass was shortened by 1 hour and the time was given to the recently launched SELENE mission. SSR playback was caught up during the following support. Space Link Extension (SLE) Testing status DSN continues to troubleshoot SLE problems with the 26m subnet. The previous telemetry problem with DSS-46 was due to an incorrect destination code in the new desktop configuration file. A 3 hour test with DSS-66 on Thursday 09/20/2007 had a successful bind and telemetry flow, but commands were not being transmitted to the spacecraft. The cause of the problem remains unknown. An ACE MOC SLE software upgrade (v3.1) is tentatively scheduled for Thursday 09/27/2007. This upgrade uses the newest libraries from the Vega/Anite commercial software and fixes other minor issues. The developers have scheduled a test of the software upgrade with DSN's Test Facility (DTF-21) for Friday 09/21/2007. DSN may also use this time to troubleshoot the 26m subnet problems. Multi-Mission Ops Center (MMOC) Planning continues to look for ways to compress the schedule for transitioning to the MMOC. ============================================================================ Anomalies: DOY 253 09/10/2007 S-ACE-0225 G07-0079 Incorrect HGA-FOT Attitude Tool The FOT inherited several tools for analyzing the output from ADS attitude software. One of these tools has occasionally been incorrect when calculating the antenna angle (HGA). A MOCR will be submitted to correct the calculation. IMPACT: Minimal. The tools are for internal checks. The Attitude/Orbit Reports sent to ASC are still correct. DOY 260 09/17/2007 S-ACE-0226 G07-0080 Data Flow from Internal DSN Test DSN scheduled an internal data-flow test for resolving the 26m SLE telemetry problem. The data flow was supposed to be internal and not sent to the MOC. Unfortunately, DSN flowed data to the MOC. The data was old data from DOY 241 2006 (1740-1744z). IMPACT: Minimal. Time and effort troubleshooting impact from the data flow. DOY 262 09/19/2007 S-ACE-0227 G07-0081 ACEDDS Hard Drive Failure On DOY 262, the /home drive failed on ACEDDS (Data Distribution Server). The SysAdmins backed up and restored the hard drive before the pass on the following day (DOY 263). IMPACT: Minimal. The ROBOTT automation sent page notifications through the backup (WINDDS). The latest DSN schedule was not downloaded during this time, but there were no changes to the ACE passes. DOY 263 09/20/2007 S-ACE-0228 G07-0082 TAPS2 Routing For unknown reasons, the AC2TAPS2 trending computer lost the default route to the ACE MOC firewall. The SysAdmins restored the route on the same day. IMPACT: Minimal. The telemetry data was captured by AC1TAPS1 trending computer and copied to AC2TAPS2 after the routing had been corrected. DOY 263 09/20/2007 S-ACE-0229 G07-0083 AC3PR3 Printer JetDirect Card The HP JetDirect card has failed on the trending printer. Hardware Maintenance has been notified. Waiting to see if replacing the JetDirect card resolves the ongoing printer problems. IMPACT: Time and effort troubleshooting.