SSOC Tohban Report for Week 50 (12 - 18 December 1994) KSC : M.Takahashi, T.Takano(12/12) and S.Masuda(12/16-) SSOC: T.Shinkawa and K.Marubashi 1. Solar Activity ------------------------------------------------------------ The most prominent active region of this week was NOAA7815(S10E22 at 15:50 Dec.12). This region has been the SXT/PFI target almost throughout the week, and produced several C-class flares on Dec.12, 13 and 14. Due to a C-class flare peaked around 11:00, Dec. 12, Yohkoh DP-mode was FL-H at the time of KSC-AOS. The activity of that day were generally small but GOES plot indicate very frequent occurrences of small flares. The largest flare (M2.5 around 05:40) occurred in Yohkoh night. 2. Standard Operation -------------------------------------------------------- 2.1 SXT Table Uploads DATE TABLE ID 12 Dec pass 2: 941212 P2 MONDAY 13 Dec pass 3: 941213 P3 DKCAL 14 Dec pass 2: 941214 P2 WEDNESDAY 15 Dec pass 2: 941215 P2 THURSDAY 16 Dec pass 2: 941216 P2 FRIDAY 17 Dec pass 2: 941217 P2 SATURDAY 2.2 STT Timer Set STT Timer was set on Monday (Pass2 on 12 Dec-94). 2.3 OG write OG 6(decimal), name FLARE was modified and written on Pass 1, 15 December. Modification is : OG 6(decimal): "FLARE" "HXT CAL ON" added. 2.4 S/C off pointing The following experiments were made on terminator crossings. For planning purpose, op_first_guess was run well in advance of each operation and information was faxed to the SXT chief observer as was requested in the operation meeting (12 Dec.). Time(UT) Comment 13-Dec-94 06:27:43 S/C E(E609,N183) 13-Dec-94 11:19:27 S/C W(W315,N175) 14-Dec-94 00:17:35 S/C N(E208,N177) 14-Dec-94 06:46:39 S/C NORMAL POINT 14-Dec-94 13:15:27 S/C NORMAL POINT 14-Dec-94 16:30:07 S/C NORMAL POINT 14-Dec-94 22:58:55 S/C S-E (8') 15-Dec-94 03:50:39 S/C S-W (8') 15-Dec-94 07:05:19 S/C E(E609,N183) 15-Dec-94 13:34:07 S/C W(W315,N175) 15-Dec-94 20:03:27 S/C N(E208,N177) 15-Dec-94 21:40:31 S/C NORMAL POINT 16-Dec-94 00:55:11 S/C NORMAL POINT 16-Dec-94 07:24:15 S/C S-E (8') 16-Dec-94 21:59:27 S/C S-E (8') 17-Dec-94 01:14:07 S/C S-W (8') 17-Dec-94 04:28:47 S/C S-W (8') 17-Dec-94 06:05:51 S/C SOUTH(8') 3. Special Operation ------------------------------------------------------- 3.1 SXT Sunset Experiment Better time profiles of X-ray and visible light at sunset by commanding flare mode from KSC on Pass 4, 15 December. 3.2 DP Soft Dump DP-soft-dump was done on Pass 2, 15 December for the purpose of investigation of the cause of the SXT data range error having occurredi in Week 49. 4. Errors & Problems -------------------------------------------------------- 4.1 KSC Command Transmitter Trouble On Pass 3 15 December, the command transmitter went wrong. As a result, they could not command "SXT CHK ENA". It recovered after the rotation of 20m antenna. KSC decided to command "ACS MOD H" earlier than scheduled. 4.2 Data Reformat Delay Something was wrong somewhere in data flow from KSC to data reformatter. New Reformatted Data were not available on 15 December. This trouble was found to be caused by transmission of ASCA data with YOHKOH name from KSC. The software in the main frame computer at Sagamihara stopped due to this error. 4.3 SXT Error A bitmap error on Pass 1 12 December was the only error of Week 50. Yobi-C command was used for recovery. 4.4 Modification of op_first_guess Pass 941217-0308 was used in spite of its low maximum elevation in order to avoid ASCA conflict. Present op_first_guess does not take it as KSC contact. Hudson-san asked Lemen-san to modify the software for worried tohbans. Now, Lemen-san is working on this problem. 5. DSN Communications ------------------------------------------------------ 5.1 DSN Strawman Schedule for W01 Because of hardware trouble in JPL, W01 strawman schedule delayed until Saturday. Meeting with ASUKA was postponed till 10:00, Monday (December 19). 5.2 DSN Preliminary Schedule for W52 We took the schedule on 15 December. The pass schedule for W52 will be made on Monday, 19 December (cf.. No KSC operation from 29 Dec. to 3 Jan.) 5.3 DSN Final Schedule for W51 We cancelled 2 passes from the final schedule taken on 15 December, because there are other 2 passes available close to them. The cancellation was confirmed on 18 December. 5.4 Real-Time Schedule Change We cancelled Pass 8419 (DOY 350), because it was only 15 minutes later than KSC pass. 5.5 Data Transmission We faxed a request for retransmission of data from the following 3 passes: DSS 66 347/17:40 - 17:45 19:23 - 19:28 21:06 - 347/21:11 . These 3 passes were included in the Post-Pass/Transmission Report, but actually nothing was received at ISAS. Later it turned out no data was received from DSN after that day. 6. Yohkoh/ASCA Pass Conflicts -------------------------------------------- In week 50, we gave ASCA Pass 5, Monday; Pass 4 Tuesday; Pass 5, Friday (Actually we took a low elevation pass as Pass 1.) In week 51, Pass 4, Wednesday and Pass 4 Thursday was given to ASCA. In addition, on Passes 4 & 5, 12/20(Tuesday), we must stop Yohkoh operation earlier than real LOS times. 7. Holiday Schedule ------------------------------------------------------- The next holiday will be Sunday Dec. 25. 8. Hikitsugi -------------------------------------------------------------- 8.1 Tohbans for Week 51 SSOC : T.Sakurai (ex. 22) and K.Shinoda K S C: M.Takahashi and S.Masuda 8.2 STT timer setting The next STT timer set is due on Monday (19-Dec-94). It has already been prepared. Please prepare the next one. 8.3 Schedules Tohbans must be very careful about the end times of operations for the following passes 12/20 Pass 3 15h56m JST 12/20 Pass 4 17h37m JST 12/20 Pass 5 19h18m JST SXT sunset experiments are scheduled on Monday 19 December, in which Flare Mode is triggered by OGs when crossing the terminator. There are many tasks remaining about schedules for Week 52 and Week 01.