SSOC TOHBAN REPORT FOR WEEK 16 (25 April - May 2 1994) Prepared on 2 May 1994 Saku Tsuneta, Litao Jiao and Barry Labonte 1 SOLAR ACTIVITY 1.1 The Sun had many small flares last week, with one C-1 event and several above B-3. The active regions are now rotated over the west limb. 2 STANDARD OPERATIONS 2.1 SXT table uploads Two campaigns kept the SXT Chief Observer and KSC Tohbans busy. Date(UT) Pass ID -------- ---- -- Apr.25 940425-1342 940426 P2 ARS2 RCKT FLITE Apr.25 940426-0104 940426 P5 ARS1 DKCAL Apr.26 940426-1342 940426 P2 ARS1 SOUTH CH Apr.26 940427-0205 940427 P4 ARS1 STD+LONG Apr.27 940427-1340 940427 P1 FIX XBP-1 Apr 27 940427-1443 940427 P2 FIX XBP-1 Apr 27 940427-1547 940427 P3 FIX XBP-1 Apr.27 940428-0102 940428 P4 ARS1 STD+LONG Apr.28 940428-1237 940428 P1 FIX XBP-2 Apr.28 940428-1547 940428 P4 ARS1 STD+LONG Apr.29 940429-1341 940429 P1 FIX XBP-3 Apr.29 940429-1548 940429 P4 ARS1 STD+LONG 2.2 STT Timer Set Executed on 26 April, Pass 2. The timer was checked by having the KSC tohbans run the Time Plot program. Next STT Timer Set should be executed on 3 May. 2.3 QUIET RATE MEDIUM was inserted in SAA's wherever possible. Please remember the rules for changing the OP: a) Duration of Day-SAA > 20 minutes. b) Command QUIET RATE MEDIUM 7 minutes after RB HV RDCT ON c) Command QUIET RATE HIGH 7 minutes before RB HV RDCT OFF The IDL command PR_FEM can print out Night and SAA times to help understand when to switch to Medium Rate. 2.4 Offset pointing South offpoints were performed to obtain terminator images to support the observations of the south coronal hole made in the previous week. These offpoints were carried out by OP and so the OP number is given. offpoint 8' south (Apr.27 00:30:00 UT; 940426-1239 OP) normal point (Apr.27 02:11:00 UT; 940426-1239 OP) offpoint 8' south (Apr.27 02:48:47 UT; 940426-1239 OP) normal point (Apr.27 03:25:35 UT; 940426-1239 OP) 3 SPECIAL OPERATIONS 3.1 Rocket support observation on pass 2 on Wednesday. 3.2 XBP collaboration, April 27 - May 1, 1994 4 ERRORS AND PROBLEMS 4.0 KSC - Yohkoh communication link This morning (May 2 JST) there was trouble at KSC with the spacecraft communication. The trouble appears to be on the ground, mostly in the tracking of the 20-meter antenna. The following is a summary of operations for this day's passes: Pass 1: Automatic tracking of the 20-meter antenna did not work. Manual tracking was used, but part of the playback data was lost. Usually PB data has about 82000 frames, but less than 80000 were received successfully. Pass 2: The same problem repeated. When the tracking is unstable, the received power varies and is low. Again, less than 80000 frames were received. Pass 3: S-band lock could not be achieved. The X-band link was established. The NEC personnel decided not to playback the onboard data. The spacecraft was left in Standby for the next orbit. Pass 4: Operation was nearly normal. S-band lock was achieved. The X-band power level was lower than usual. Pass 5: Operation appeared normal. We monitored the pass from B-toh and all looked well. 4.1 At Pass 1 on April 29 (Saturday morning JST) there was a delay in beginning the transmission of the playback data because the Fujitsu personnel arrived late. About 30% of the playback data was lost. 4.2 SXT Errors SXT Bit Map error occurred on April 27, Pass 3. 4.3 DSN Pass deletions Please pay attention to spacecraft Day/Night in deleting DSN passes. There are several days in Week 19 that had Night contacts deleted and Day contacts kept. 4.4 B-toh FAX jams The B-toh FAX machine indicates a paper jam, but there is no jam. The indicator light is false. To clear the light, open and close the lower door on the right side of the FAX machine (side near the door). The FAXs are not lost, just stored in memory until the indicator light is cleared. 4.5 This week email for Uchida-san returned undelivered. If this repeats, his address in flare1:/etc/aliases should be updated. 5 DSN COMMUNICATIONS All worked fine. 6 YOHKOH/ASCA PASS CONFLICTS 6.1 In the week 17, there was no conflict between Yohkoh passes and Asca ones. Preparing the schedule for week 18 we found one conflict between the Yohkoh and Asca operations, for May 6. The Yohkoh passes were moved forward by 1 to accomodate. This negotiation was conducted at KSC by the KSC tohbans because the ASCA SSOC personnel were not available. 6.2 Hara-san's Yohkoh/Asca conflict plot is missing. In any case, the program to generate the plot should be in a known place. 7 HIKITSUGI 7.1 Tohbans for W18 (May 2-May 9): SSOC: Sato J., Takeda KSC: Shoji, Irie 7.2 Remember to delete and condense old files on the Mainframe once each week. 7.3 We again requested retransmission of the DSN pass of April 5 at 20:46 UT. We have not confirmed that the data has arrived because Katano-san is out this week. 7.4 Set the STT timer on May 3. 7.5 The RASM password expires on May 4. Please change it. ----------------------------------------------------------------------------