STEREO Weekly Meeting Minutes for 2014-07-01 (Week 27) ANNOUNCEMENTS ------------- * See the discussion below about solar conjunction operation testing during week 28. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 26 (Jun 23-29) * On day 175 (Jun 24), during the DSS-55 support for Ahead, telemetry lock was lost intermittently between 0603z through 0726z due to heavy rain. This anomaly resulted in the loss of 3290 frames of SSR data. See DR #M108062 for more information. * On day 176 (Jun 25), during the DSS-55 support for Ahead, telemetry lock was lost intermittently between 1038z through 1314z due to a receiver anomaly. A second receiver was added and telemetry lock was reacquired nine minutes later. This anomaly resulted in the loss of 9372 frames of SSR data. See DR #M108066 for more information. * On day 180 (Jun 29), during the DSS-65 support for Ahead, turbo decoder lock was lost at 1049z due to a receiver anomaly. Conscan was disabled to clear the condition. This anomaly resulted in the loss of 128 frames of SSR data. See DR #M108104 for more information. * On day 174 (Jun 23), on Ahead, Fault Protection version 2.3.14 was loaded to EEPROM and Earth Acquisition mode bypass was selected in preparations for solar conjunction testing to commence on day 187 (Jul 6). * On day 177 (Jun 26), the 20th HGA Calibration on Ahead was successfully executed at 0130z. * On day 178 (Jun 27), on Ahead, DHS parameters version 1.1.7 and MOps macros 1.1.22 were loaded to EEPROM in preparations for solar conjunction testing to commence on day 187. * On day 174 (Jun 23), during the DSS-14 support for Behind, the transmitter was red before BOT. The track was shorted to a duration of 4.1 hours to allow the transmitter to be repaired. This incurred a loss of two hours of SSR data. * On day 175 (Jun 24), during the DSS-43 support for Behind, telemetry lock was lost intermittently between 0429z through 0440z due to heavy rain. This anomaly resulted in the loss of 853 frames of SSR data. * On day 176 (Jun 25), during the DSS-63 support for Behind, turbo decoder lock was lost briefly at 0831z. This anomaly resulted in the loss of five frames of SSR data. * The average daily SSR playback volume during the week was 4.1 gigabits for Ahead, and 4.3 gigabits for Behind. * The temperatures of the HGA feed horns continues to be monitored. The Ahead feed horn temperature is currently 107.9 degrees at an SLE angle of 9.2 degrees, and continues to rise. The Behind temperature is currently 108.9 degrees at an SLE angle of 8.3 degrees. The Behind SLE angle is slowly increasing, leading to lower temperatures. The angle will level off soon. It's expected that the Ahead temperature will exceed that of Behind next week. The goal is to keep the temperature below 125 degrees. The sensor can only go to 136 degrees. Damage occurs between 150-180 degrees. The predicted dates to reach 125 degrees are Aug 23 for Ahead, and Dec 1 for Behind. Week 27 (Jun 30-Jul 6) * The IMPACT team uploaded a patch this morning (Jul 1) for the LET instrument on Ahead. However, preliminary indications are that it didn't go as expected. * Friday, July 4 is the Independence Day holiday. * Telemetry lock was going in and out at the beginning of the Behind track yesterday (Jun 30) using station 14, due to a problem with subreflector positioning. The telemetry rate was decreased to 360 kbps to finish out the track. This left a lot of data on the recorder, and there are indications that the SECCHI buffer is approaching full. * The 64th momentum dump on Behind will be carried out on Wednesday, Jul 2, with ignition at 20:00 UT. * Solar conjunction testing on the Ahead spacecraft will start Sunday, Jul 6. A detailed timeline will be sent out. On Sunday, at 18:00 UT, the instruments will be powered off, and the SSR will be played back until empty. This will be followed by reconfiguring the SSR for solar conjunction. Near the end of the track, the HGA angle bias will be loaded for the next track. * Ahead has 12 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Jun 30 (D63 at 720 kbps), Tuesday, Jul 1 (D43 at 720 kbps), Thursday, Jul 3 (D14), Saturday, Jul 5 (D43 at 720 kbps, D43), and Sunday, Jul 6 (D63). The following passes will be carried out at 160 kbps: Wednesday, Jul 2 (D54), Friday, Jul 4 (D55), and Sunday, Jul 6 (D25). * Behind has 10 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Jun 30 (D14 at 720 kbps), Tuesday, Jul 1 (D63), Wednesday, Jul 2 (D14), Thursday, Jul 3 (D14 at 720 kbps), and Friday, Jul 4 (D14 at 720 kbps). The station 54 pass on Saturday, Jul 5, will be carried out at 160 kbps. The following station 26 passes will be carried out at 240 kbps: Saturday, Jul 5, and Sunday, Jul 6. * SECCHI asks whether their pointers can be changed before the momentum dump tomorrow (Jul 2) on Behind. They expect their partition to be full, and don't want to lose the calibration data they take in conjunction with the momentum dump. Week 28 (Jul 7-13) * Behind will reach perihelion on Jul 9. System momentum will be high, and the SECCHI stepped calibration roll will be delayed by one week. * Behind has 8 passes during the week, and overall coverage is nominal. No 70 meter passes are scheduled during the week. * Solar conjunction testing will be continued on the Ahead spacecraft during the week. On Monday, Jul 7, the Ahead spacecraft will be on the first side lobe. The telemetry rates should be 10 kbps downlink, and 500 bps uplink. * The 69th momentum dump on Ahead will be conducted at 09:00 UT while the HGA is on the first side lobe. The momentum will be adjusted to a lower setting than usual, 8 N-m-s, as will be done during solar conjuction. * After the momentum dump, the Ahead spacecraft will be commanded into a reset at 09:45 UT. It will then be at a data rate of 633 bps downlink, and 125 bps upload, and will come up on the HGA second side lobe. No more commands will be sent up to the spacecraft for the next three days to simulate the situation during conjunction. The pass continues until 15:30 UT. * On Wednesday, Jul 9, a time-tagged command will start the Ahead spacecraft rolling. It will then cycle through the antennas, starting with the -Z LGA 7 hours later at 09:45 UT. After 12 hours it will switch to the +Z LGA at 21:45 UT. The telemetry rate at this point will be 12 bps downlink, 28 bps uplink. * On Thursday, Jul 10, at 09:45 UT, the Ahead spacecraft will autonomously reset after not having received any commands for 3 days. It will continue to rotate. There will be a one hour support with station 55 to observe this. After the reset, only the carrier will be visible--the station will not be able to lock on. * A time-tagged command will put the Ahead spacecraft back into three-axis stabilized mode on the 2nd side lobe at 19:45 UT, prior to the second DSN support. This will be followed by a test of the 1 degree HGA off-point configuration. The telemetry rate on the 70 meter station will be 360 kbps downlink, and 2 kbps uplink. * Ahead spacecraft recovery will start immediately after the 1 degree HGA off-point test. The SSR will be played back, and then reconfigured back into operational mode. Nominal SSR playback will be carried out after that. The HGA will be returned back to nominal pointing for passes starting Saturday, Jul 12. * Instrument recovery will start on Saturday, Jul 12, and continue through the weekend. There are four supports on Saturday. There's a chance that instrument recovery could start as early as Friday, Jul 11, at 05:30 UT, but the schedule is very tight. ESA passes have been added on Monday and Tuesday of the following week to assist with instrument recovery. The instrument teams will be kept informed as the schedule progresses. * There was some discussion about survival heater operations. The autonomy rules on SECCHI will automatically request survival heater power during recovery. * Overall, Ahead has 13 passes during the week, with ten 70 meter passes, and three 34 meter passes. Week 29 (Jul 14-20) * There are two supports each day on Monday and Tuesday to assist with instrument recovery, for a total of 10 hours and 12 hours respectively. The second support each day is an ESA Malarque pass. * On Sunday, Jul 15, is the 29th SECCHI Step Calibration on Behind at 0435z for perihelion. System momentum will be 3 N-m-s. * On Sunday, Jul 15, the 20th HGA calibration on Behind will be carried out at 13:00 UT, during the station 63 pass. The SPE angle is 8.8 degrees, which is safe for carrying out the calibration. * Ahead has 13 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Thursday, Jul 17 (D43 at 720 kbps), Friday, Jul 18 (D63), Saturday, Jul 19 (D43 at 720 kbps), and Sunday, Jul 20 (D14 at 720 kbps). The following passes will be carried out at 160 kbps: Tuesday, Jul 15 (D55), Wednesday, Jul 16 (D65), Thursday, Jul 17 (D55), Saturday, Jul 19 (D55 and D15), and Sunday, Jul 20 (D65). ESA Malargue passes are scheduled for Monday and Tuesday, Jul 14-15. * Behind has 10 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Jul 14 (D63), Tuesday, Jul 15 (D63 at 720 kbps), Friday, Jul 18 (D63 at 720 kbps), and Saturday, Jul 19 (D14). The following passes will be carried out at 160 kbps: Wednesday, Jul 16 (D55), Thursday, Jul 17 (D45 and D54), Friday, Jul 18 (D45), Saturday, Jul 19 (D25) and Sunday, Jul 20 (D55). Week 30 (Jul 21-27) * On Thursday, Jul 24, a 3 hour project interface test (PIT) with the new 34 meter station D35 at Canberra will be carried out. There will be no instrument commanding or SSR playback during this pass. DSN suggests scheduling an SLE test with station 35 a week or two prior to the PIT test. * On Sunday, Jul 27, a return-to-service pass with station 26 will be carried out. There will be no instrument commanding or SSR playback during this pass. * Ahead has 10 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Tuesday, Jul 22 (D63 at 720 kbps), Wednesday, Jul 23 (D14), Friday, Jul 25 (D14 at 720 kbps), Saturday, Jul 26 (D43), and Sunday, Jul 27 (D14 at 720 kbps). The following passes will be carried out at 160 kbps: Monday, Jul 21 (D54), Thursday, Jul 24 (D55), Saturday, Jul 26 (D54), and Sunday, Jul 27 (D55). * Behind has 12 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Jul 21 (D43 at 720 kbps and D63), Tuesday, Jul 22 (D14 at 720 kbps), Wednesday, Jul 23 (D14 at 720 kbps), Friday, Jul 25 (D63), and Saturday, Jul 26 (D14 at 720 kbps). The following passes will be carried out at 160 kbps: Thursday, Jul 24 (D54), Friday, Jul 25 (D24), Saturday, Jul 26 (D55), and Sunday, Jul 27 (D54). Week 31 (Jul 28-Aug 3) * The 65th momentum dump on Behind will be carried out on Jul 28, with ignition at 19:45 UT. This is earlier than usual due to schedule constraints. * C&DH flight software version 3.2.4 will be written EEPROM copy 1 on Ahead on Jul 29. * Ahead has 10 passes during the week, and overall coverage is nominal. There is one pass at 720 kbps, one pass at 480 kbps, one pass at 240 kbps, six passes at 160 kbps, and one pass at 120 kbps. * Behind has 10 passes during the week, and overall coverage is nominal. There are three passes at 720 kbps, two passes at 480 kbps, and five passes at 120 kbps. Week 32 (Aug 4-10) * The 70th momentum dump on Ahead will be carried out on Aug 4, with ignition at 18:00 UT. * The HGA angle on Ahead is expected to reach the soft stop on July 28. After this, the telemetry signal will start to drift off the center of the main lobe, and the achievable telemetry rate will start to drop. During week 32, the maximum telemetry rate will still be 720 kbps. This drops to 480 kbps in week 33, and 360 kbps in week 34, after which the spacecraft will switch to side lobe 1. There are two 34 meter supports during week 32 which will be at 96 kbps, on Aug 6 and 9. After that, only 70 meter supports will be used. * The switch to 1 degree offpoint, originally scheduled for Aug 5, has been postponed, since the soft stop will start introducing an increasing off-point starting July 28. If there are any sudden increases in temperature, than the 1 degree offpoint will be commanded. * After the spacecraft test next week, the MOps team will be able to focus on instrument operations for Ahead. If all goes well, there's a possibility that the scheduled off time for Ahead could be mitigated, or even eliminated. * Ahead has 10 passes during the week, and overall coverage is nominal. There are six passes at 720 kbps, one pass at 480 kbps, one pass at 240 kbps, and two passes at 96 kbps. * Behind has 9 passes during the week, and overall coverage is nominal. There are three passes at 720 kbps, one pass at 480 kbps, three passes at 240 kbps, one pass at 160 kbps, and one pass at 120 kbps. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 27: M Jun 30 (181) T Jul 01 (182) W Jul 02 (183) Behind: Momentum dump, 20:00 UT T Jul 03 (184) F Jul 04 (185) Independence Day S Jul 05 (186) S Jul 06 (187) Ahead: Turn instruments off, 18:00 UT Notes: * Solar conjunction operations test on Ahead, Jul 6-12. All science instruments will be off during this test. ------------------------------------------------------------------------------- Scheduled activities for Week 28: M Jul 07 (188) Ahead: Momentum dump using first side lobe, 09:00 UT Ahead: Command s/c reset, 09:45 UT, up on second side lobe T Jul 08 (189) W Jul 09 (190) Ahead: Start spacecraft rotation via time-tagged command Behind: Perihelion T Jul 10 (191) Ahead: Autonomous reset, 09:45 UT Ahead: Stop rotating, 19:45 UT, recover back to HGA +1 degree F Jul 11 (192) Instrument SSR partitioning and real-time telemetry rates due S Jul 12 (193) Ahead: Back to nominal HGA pointing. Power on instruments. S Jul 13 (194) Ahead: Continue instrument recovery Notes: * Solar conjunction operations test on Ahead, Jul 6-12. All science instruments will be off during this test. Instrument power on may start as soon as Friday, Jul 11. ------------------------------------------------------------------------------- Scheduled activities for Week 29: M Jul 14 (195) T Jul 15 (196) Behind: SECCHI stepped calibration roll, 04:35 UT Behind: HGA calibration, 13:00 UT W Jul 16 (197) T Jul 17 (198) F Jul 18 (199) S Jul 19 (200) S Jul 20 (201) Notes: * Continuation of instrument power on activities through the week, as needed. ------------------------------------------------------------------------------- Scheduled activities for Week 30: M Jul 21 (202) T Jul 22 (203) W Jul 23 (204) T Jul 24 (205) Behind: Project interface test with new 34 meter station D35 F Jul 25 (206) S Jul 26 (207) S Jul 27 (208) Behind: Return-to-service test with D26 ------------------------------------------------------------------------------- Scheduled activities for Week 31: M Jul 28 (209) Behind: Momentum dump, 19:45 UT T Jul 29 (210) W Jul 30 (211) T Jul 31 (212) F Aug 01 (213) S Aug 02 (214) S Aug 03 (215) Notes: * Ahead is expected to reach the soft stop on the HGA angle on July 28. The telemetry rate will slowly drop after this. ------------------------------------------------------------------------------- Scheduled activities for Week 32: M Aug 04 (216) Ahead: Momentum dump, 18:00 UT T Aug 05 (217) W Aug 06 (218) T Aug 07 (219) F Aug 08 (220) S Aug 09 (221) S Aug 10 (222) ------------------------------------------------------------------------------- Upcoming events: 2014: * Aug Ahead: HGA on main lobe, offpoint 1 degree (TBC) * Aug 14 Ahead: Solar Conjunction Readiness Review * Aug 20 Ahead: Instrument power down * Aug 23 Ahead: HGA on 1st side lobe * Sep 07-Nov 15 Behind: Passage of Comet Siding Spring through HI2-B * Sep 18 Behind: MOps Readiness for S/C Testing Review * Sep 29-Oct 6 Behind: Test of solar conjunction operations * Sep 21 MAVEN arrival at Mars * Oct 17 Behind: Comet Siding Spring encounter with Mars * Oct 20 Ahead: Instrument power on * Oct 23 Behind: Solar Conjunction Readiness Review * Nov 10 Ahead: HGA on 2nd side lobe * Dec 1 Behind: HGA on 1st side lobe 2015: * Jan 6 Behind: HGA on 2nd side lobe * Jan 20 Behind: Instrument power down * Jan 22 - Mar 23 Behind: Spacecraft behind Sun * Mar DAWN - Ceres arrival * Mar 22 Ahead: Instrument power down * Mar 24 - Jul 07 Ahead: Spacecraft behind Sun * Mar 30 Behind: Instrument power on * Apr 25 Behind: HGA on 1st side lobe * Jul DAWN - End of nominal mission * Jul 8 Behind: HGA on 2nd side lobe * Jul 14 Ahead: Instrument power on * Sep 24 Ahead: HGA on 1st side lobe * Nov 20 Behind: HGA on 1st side lobe * Dec 29 Ahead: HGA on main lobe, offpoint 1 degree Ahead: SSR playback and reconfiguration, S/C checkout * Dec 31 Ahead: Instrument recommissioning 2016: * Jan 2 Behind: HGA on main lobe Behind: SSR playback and reconfiguration, S/C checkout * Jan 5 Behind: Instrument recommissioning * Jan 27 Both: HGA calibration * Feb 19 Ahead: HGA on main lobe * Mar 16 Both: Post Solar Conjunction Assessment Review * Jul 5 Juno arrival at Jupiter 2017: * Jul 11 Ahead: Switch downlink rate to 160 kbps * Jul 22 Behind: Switch downlink rate to 160 kbps 2018: * Mar 5 Ahead: Mercury transit