SSOC Tohban Report for Week 09 (28 FEB - 6 MAR, 1994) 7 March, 1994 (Mon) Taro Sakao and Kazuya Shinoda (SSOC) Kiyoshi Ichimoto and Shinji Kubo (KSC) 1. Solar Activity Solar activity was not very high last week. There was one M-class flare on Feb.27 at around 8:30 UT. In the latter half of week 9 (after Mar.3), NOAA AR 7682 frequently produced small flares (typically around GOES C1). As this active region is located near the west limb, solar activity might become low again this week. 2. Standard Operations 2.1 SXT table uploads Date(UT) Pass ID Feb.28 ---- ---- Mar.1 ---- ---- Mar.2 940302-0208 940302 P4 ARS1 DKCAL 940302-1446 940302 P2 ARS1 STD+LONG Mar.3 940303-1547 940303 P2 DEEP CORONA (for S16' offpoint) 940304-0206 940303 P4 ARS1 STD+LONG Mar.4 ---- ---- Mar.5 ---- ---- Mar.6 940306-1342 940306 P2 ARS1 STD+LONG Mar.7 940307-0001 940306 P4 ARS1 STD+LONG 2.2 STT timer set Done on Mar.1 0:00 UT (next will be Mar.7 ~21:00 UT) 2.3 Offset pointing S/C 16' south (Mar.3 23:10 UT; 940303-1547) S/C normal point (Mar.4 2:40 UT; 940304-0206) An attitude log including the above two maneuvers has been prepared as S88239.ATTLOG.DATA(TOBAN). No East-West offpoint was conducted last week. 2.4 Calibrations None. 3. Errors and problems 3.1 Operations Several mistakes both on KSC and SSOC sides as well as a trouble in KSC MS-175 computer caused big troubles in Yohkoh operation on Feb.28 (Mon): OP was not uploaded until the 4th pass (it should have been uploaded at the 1st pass). These troubles were caused by the followings: o SSOC tohbans forgot to transfer the OP to KSC. KSC tohbans did not notice it before the 1st-pass operation. o In pass 2, MS-175 was in trouble and the OP could not be uploaded again. o In pass 3, KSC tohbans mistakenly issued OP-START instead of OP-CONTINUE (The OP was uploaded in this pass).On the other hand, SSOC tohbans specified the OP CONTINUE address in a decimal number while it should have been in hexadecimal. It seems that a part of KSC downlink data at 21:10 UT on Mar.2 was lost due to an incomplete dump caused by delay in issuing the TMX-H-REP command. 3.2 SXT error During the above troubles, an SXT error (Mailbox range error) occurred at the 3rd pass (Feb.28 ~3:00 UT; 940228-0206). It seems that this error has occurred for the first time. SXT was recovered by Yobi-C command during the 4th pass. KSC tohbans conducted a MANU FL H -> MODE CTL AT test in the 1st pass of Mar.1 (940228-1445) during daytime to see if any SXT error is triggered by Flare mode. They found no SXT error in this test. A bitmap error occurred at the 1st pass on Mar.7 (JST). The error was fixed by the Yobi-C command. 3.3 BCS error A BCS error was found in the 2nd pass of Mar.5 JST (Mar.4 21:50 UT; 940304-1444) and was recovered by KSC tohbans in the next pass (Mar.4 23:30 UT; 940304-1547). 3.4 BDR error in week 8 Nomura san of Fujitsu Co. visited us on Feb.28 (Mon) to investigate the cause of the BDR error which occurred during a dump at 940226-0205. He said that the error was well explained by an occurrence of SEU in the BDR controller. 4. DSN Communications 4.1 Cancellations A DSN downlink pass (Mar.1 (DOY 60) Canberra ~15:30 UT) was cancelled due to DSPSE support. We noticed this after uploading the corresponding OP at the 1st pass of Mar. 1 and uploaded a revised OP at the 4th pass (Mar.1 ~3:20 UT; 940301-0207). There were several additional real-time cancellations by DSN. All of them were found before uploading the corresponding OPs. We found that we have lost some DSN dump data (Feb.21 ~14:30 UT @Canberra): Although this pass had been deleted from the latest final schedule, downlink commands for the pass were still included in the corresponding OP. 4.2 Data delay It was reported in the previous weekly operations meeting that the DSN data of Feb.16 DSS-66 (Madrid) 13:49-13:59 UT was found short of 639 blocks. Last week we received a revised post-pass transmission log for the above pass from JPL which says that JPL in fact sent exactly the same number of blocks as we received at ISAS. All the data until DOY 56 (Feb.25) has arrived at ISAS and is stored in SIRIUS. However, the following two DSN downlink data had been partly corrupted and had some problem in storing in the SIRIUS database. We requested JPL for their retransmission on Mar.3: DSS-46 (Canberra) DOY 56 (Feb.25) 10:45-10:53 (BOT-EOT) " " 12:26-12:37 5. Operations While isass0 is Down Due to system upgrade of isassN machines, isass0 was down on Mar.5 (Fri). Thanks to Linford san, Lemen san, and other Lockheed people, we could use Yohkoh operations software (e.g. krasm) on isass2 without any trouble. Relating to krasm, however, we need be careful that when isass0 is down the directory $DIR_GEN_ORBIT_RAW, where RASM files (final/preliminary/strawman schedules) are located, is different from what it used to be when isass0 is up: RASM files transferred while isass0 is down will become invisible to some programs such as cancel_dsn when isass0 resumes its service. 6. Hikitsugi 6.1 STT timer Set See section 2.2. 6.2 E-mails Please be sure to store e-mails to and from yohkoh@flare1 in mail/mail_94_w10. 6.3 SXT table printouts As was discussed in the last week's operations meeting, SXT table printouts, which used to be printed out with the bld.B 3F FACOM printer, are no longer made unless there is any trouble in upload. 6.4 Tohbans for W10 SSOC: Kentaro Yaji and Yukio Kozuka KSC: Kiyoshi Ichimoto and Takehiko Shinkawa