SSOC Tohban Report for Week 43_95 (October 23 - October 30, 1995) SSOC: S. Morita, Te. Watanabe KSC : K. Yoshimura, M. Akioka Attendance at WOM: L.Acton, H.Hudson, R.Kano, J.Khan, T.Kosugi, M.Mizutani, Y.Ogawara, S.Morita, T.Sakao, S.Savy, M.Sawa, A.Sterling, Te.Watanabe, T.Yoshida 1. Solar Activity -------------------------------------------------------- The solar activity has decreased an order of magnitude from the level of B to A during the week. The solar eclipse occurred in the declining phase when the active ragion NOAA 7912 turned behind the limb. Three C-class flares were reported on 22-Oct during the Yohkoh observing periods. 2. Standard Operations --------------------------------------------------- 2.1 SXT Table Uploads : 5 total --------------------------------------------------------------------- Date Pass number Name --------------------------------------------------------------------- 23-Oct-95 4 951023 P3 ARS2 STD+LONG 24-Oct-95 1 951024 P1 ARS0 ECLIPSE1 24-Oct-95 5 951024 P5 ARS0 ECLIPSE2 25-Oct-95 2 951025 P3 ARS1 STD+LONG 28-Oct-95 5 951028 P5 ARS1 STD+LONG --------------------------------------------------------------------- Each time an SXT Table was uploaded a patrol image was taken by executing the command `BC 8C 05'. 2.2 STT Timer Setting The STT Timer was set on 23-Oct-95 (Monday) pass # 2, 26-Oct-95 (Thu) pass #6, and 28-Oct-95 (Sat), pass #5. The next timer setting should be 4-Nov-95 (Sat). 2.3 OP offpoints During the eclipse, the E17-N00 and W09-N00 offpoints were performed. The E17-N00 offpoint was also done on 23-Oct-95 for the SXT terminator image. 3. Errors & Problems ------------------------------------------------------- 3.1 SXT Errors None onboard. The table comparison on 23-Oct-95 (Fri) pass #3 failed. The mirror image stored in MS/KSC had 2 noncompares. The reason for this is yet known. One of the SXT super tohbans (Kano_san) found that the noncompares were in the comment of the table and harmless. The phenomenon was cleared, as the SXT chief observer made the next table, which has the comment to overwrite these bytes. 3.2 BCS Errors A BCS error was found on 25-Oct-95 (Wed) pass 2 and recovered on 27-Oct-95 (Fri) pass 4. The other one was found on 28-Oct-95 pass 3 and recovered at pass 5. 3.3 KSC MS Computer Problem The command upload control programme in MS/KSC was hung during the critical operation of the ACP program installation from BFM. 3.4 Flare1 printer The flare1 printer failed on 9 October and has not yet been fixed. The setup in the ASCA w/s, minazuki, for printing the queue from flare1 was corrupted on 27-Oct-95 (Fri) and restored on the same day. 3.5 Safe-hold and recovery operations 3.5.1. Trigger of ACP SHD (IOG #3) At around 7:30UT on 24-Oct-95 (Tue), a night fall for the s/c between the 5th and 6th passes of the eclipse day, the IOG #3 was triggered from ACP by the loss of TFSS sun presence signal. By the eclipse hunters' checking of the SXT images during the 6th pass, and subsequent analyses of the delay-look data, this was supposed to happen because of a wrong orbit timer setting at 6:0:0(OP: O/T ENA2). It was however absolutely no fault of Kano_san, who prepared the OG, because the command was correctly prepared, issued, and stored in the ACP command register, but supposed to be set wrongly into the orbit timer. Regrettable was that we had no data at that time, because the final setup of the timer could be only checked in the ACS mode, and we can only guess in the normal telemetry modes from the STn values copied to the D/N timer at the s/c sunrise. Fujiwara_san of NEC, an ACP expert, was still puzzled by the cause of the wrong set up and investigating it. He may request some test operations later. orbit timer setting=`clock/T1/T0' orbit timer for ACP; night start time/orbit period (telemetried in ACS mode) day/night timer for ACE; night start time/orbit period (ST1) (ST0) n->d d->n n->d orbit timer |--------------------------------|******************************| clock->T1 clock->T0 clock reset d/n timer |--------------------------------|******************************| T1->ST1 clock->ST0 actual |--------------------------------|-----|************************| ST2(margin)=60sec 24-Oct-95 ---------|*********|----------------|************|---------------- OT-ENA2 KSC 5th pass ACP-SHD KSC 6th pass T1=3688sec d/n timer ST1=4134sec 3.5.2. Thorny path to recover The following is a brief summary of the recovery operation which took the full four day operations from 25-Oct- (Wed) to 28-Oct-95 (Sat). ---------------------------------------------------------------------------- Date Pass Operations Results ACS status ---------------------------------------------------------------------------- 25-Oct-95 2 IRU(X,Y,Z) warmup, CAQ ACP-SHD->CAQ->ACE-SHD Y-gyro failed 4 IRU(X,Z,S) warmup, MW rps setup ACE-SHD MW command error (from ASCA) 5 MW rps setup, CAQ CAQ WDT failure flag ---------------------------------------------------------------------------- 26-Oct-95 1 ACP-A reset OBS failed starting up CAQ->ACE-SHD 2 ACP-A/B reset OBS failed starting up ACE-SHD 3 ACP MEM check #errors=1,827 ACE-SHD 4 BFM MEM check #error=0 ACE-SHD 5 ACP program installation from BFM ACE-SHD MS@KSC hungup (extra) 6 MW rps setup, CAQ ACE-SHD->CAQ ---------------------------------------------------------------------------- 27-Oct-95 1 IRU(X,Z,S) warmup CAQ STT map mode failed 2 ACP parameters setup CAQ STT map mode OK 3 Z-axis maneuver dZ=18 degree CAQ 4 Z-axis maneuver, STT timer setup CAQ 5 Z-axis, STT program installation CAQ STT TRK start STT RAM check=error free ---------------------------------------------------------------------------- 28-Oct-95 1 STT tracking area adjustment CAQ 3 STT tracking area adjustment, FAQ, NOR CAQ->FAQ->NOR 5 STT timer setup, SHD ENA NOR Canopus tracked normal operation resumed ---------------------------------------------------------------------------- 4. DSN Communications ----------------------------------------------------- 4.1 DSN Final Schedule for W44 We canceled 3 DSN contacts from the Final Schedule for W44, which were close to the KSC contacts and had been kept till the Y-A-conflict adjustment meeting with Prof. Nagase. 4.2 DSN Preliminary Schedule for W45 We made 12 cancellations for W45. 4.3 DSN Strawman Schedule for W46 We canceled 78 DSN contacts from the Strawman Schedule for W46. 4.4 Pass additions None. 4.5 Re-transmission requests Katano_san sent 5 re-transmission requests for data as follows: DSS 76, 285/19:38 5th request: 27-Oct-95 DSS 76, 287/02:49 4th DSS 46, 288/16:28 4th DSS 76, 292/21:51 3rd DSS 76, 295/21:06 2nd Prof. Yamada (ISAS) reported the down of the JPL data transfer system on 24- Oct-95 (Tue). It was restored sometime during the week, while the SSOC tohbans were absorbed in participating in the ACS recovery operations. 5. Yohkoh/Asuka/SFU Pass Conflicts at KSC --------------------------------- In W44, 6 KSC passes were lost because of the conflicts with ASCA. There were no pass conflicts between Yohkoh and SFU. The orbit of SFU will be changed in two weeks, and it will be operated in the week of 12- to 18-Nov- 95 at KSC. 6. Special operations ------------------------------------------------------ 6.1 OGs for the eclipse OGs of #33, #34, #54, #115 are still in the OG list. 6.2 Eclipse 24-October The eclipse observation was very successful, except misunderstanding of the moon loci relative to the sun. The s/c was offpointed to the opposite direction (east) at the first moon approach. We should remember that the moon moves faster than the sun and always comes from the west. 7. Holiday Schedule -------------------------------------------------------- The next holiday will be on Sunday, 5-Nov-95. The NAOJ open-house is scheduled on 3-Nov-95 (Fri), the Culture-Day (Bunka_no_hi) Holiday. 8. Hikitsugi Items --------------------------------------------------------- 8.1 Tohbans for Week #44 KSC : M. Akioka, M. Yamamoto SSOC : R. Kano, M. Mizutani 8.2 STT Timer Setting The next STT Timer should be done on Saturday, 4-Nov-95 (Sat). 8.3 Offpoint terminator images If terminators appear in the OP generated by running `op_first_guess,' then the OP should be faxed to the SXT_CO (Chief Observer) in D-toh. The SXT_CO will then inform the SSOC tohbans if offpointing will be carried out. If so, the OP will need to be edited appropriately. 8.4 Transmission of OP Shuto_san reported the MS systems at SSOC/KSC were designed that you could send OG/OPs and SXT tables anytime, as far as the systems are up. He did not recognize the system interference or hung during SFU operations. He suggested us to give him report when we meet with the problems of transfer so that he would be able to analyse and debug the system. Please note that the OP could be transmitted to KSC anytime and report them to Shuto_san, if you have troubles. 8.5 SXT Patrol Image Dumps The command `BC 8C 05(Hex)' should be executed whenever an SXT table upload occurs. This command dumps an SXT patrol image which is needed to check the ARS parameters since the Sun is very quiet.