Shift H25 Start at 1999:228:02:00 = 1999 Aug 15 10:00pm End 1999 Aug 16 6:00am (Times will be given in GMT on day 228. In general times are rough, not precise.) SOT Lead/FP Sci MJ Spac/Aspect FOT/Sci liaison HRC ACIS PPP, PB Plan ---- Complete CAP 279 (ACIS data collection during NPM momentum dump test) Next daily load OBSIDs 1055, 1056 Radiation Zone Entry Events ------ 02:52 Currently running daily load terminated 03:05 New daily load send to spacecraft and activavted (SCS 130 starts ~05:00) 03:42 start CAP 282 - NPM momentum dump ACA start track check-out 03:50 break track on all 8 ACA search windows 03:55 start cap 283 to build up stored momentum 04:20 momentum unloading starts 04:28 ACIS stop science 05:00 New daily load start 05:07 OBSID 1055 05:40 SIM focus moved to motor step -932 05:42 ACIS start science 05:45 Maneuver ended 06:40 ACIS stop science OBSID 1056 06:42 Maneuver starts 06:44 Maneuver ended 06:55 ACIS start science 07:26 ACIS stop science 07:27 ACIS safing for rad zone entry 07:50 RADMON disabled Notes/Issues/Problems --------------------- The daily load running at the start of the shift was terminated when the only remaining commands were to turn off the transmitter and power amplifier, which it would do at ~04:00. Termination of the SCS left the transmitter on so that no real-time data would be lost and allowing the planned execution of the ACIS stop science command in CAP 279 shortly before the resumption of the planned observing program. Flight note 282a was distributed on "Facility Maintenance Activities". There will be no EHS availability during the LOS period 228:11:25-228:16:40 and also during the LOS period 229:02:35-229:08:40. The current daily load used an OR to operate ACIS during the ACA Field Distortion Coefficients measurement (OBSID 1266). However the OR includes dither which is not compatible with the ACA measurements. A CAP must be run to turn off dither for the observation (~228:22:30). Dither will have to be re-enabled after the measurement is complete (~229:02:00). The necessary commands (AODSDITH for dither disable and AOENDITH for dither enable) submitted as CAP 284. In the new daily load all OBSID changes are coincident with the ACIS Stop Science Commands rather than delayed by the desired 3 minutes. This will be true for all ACIS observations performed over the time frame 228:05:00 to 229:10:00. The last command in the DOT is a "stop science" so a delay should be included in the next load. ACA did not acquire a star in slot 7 after maneuver for OBSID 1055. For OBSID 1056 it did not acquire a star in slot 6. I noticed that the RADMON process was disabled after the radiation zone entry. The disable command is in the daily load along with an enable command prior to radiation zone exit. I had not been aware of this change to the radiation zone preparations.