Oct 28, 2003 Shift Report -------------------------- SCS107 ran autonomously today at 301:03:02, due to high radiation from the X17 solar flare. SCS107 ran nominally. Low energy solar proton fluxes are still increasing. The expected time range for the arrival of a shock at the Earth from this event is 302:0000 UT to 302:2100 UT, with a best guess time of 302:0800 UT. Our best guess plan for resuming science is to resume after the next perigee, with science observations starting at about 304:0530 UT, which is 45.5 hours after the best guess shock arrival time. FOT MP is proceeding with planning for that timeline. FOT MP tomorrow will build a load with this science resumption, and with a maneuver to an attitude for momentum management on the descending leg of the present orbit. This maneuver would occur at about 303:1000 UT, with an associated load uplink opportunity at 303:0345 UT (tomorrow night). The load would be built with the maneuver in a separate SCS, that can be uplinked and activated without initiating any science. This maneuver could be performed without enabling RADMON and SCS107. However, ACIS would like to perform a CTI measurement on the descending leg of the current orbit. If this CTI is approved, then RADMON and SCS107 would be enabled to protect ACIS. (We should be conservative in approving the ACIS CTI based on expected radiation rates, to prevent yet another SCS107 trip and associated replan cycle). The load will be built with a RADMON disable before perigee, and the ACIS team would initiate the CTI by ground commanding using a CAP. Oct 29, 2003 Shift Report ------------------------- Radiation rates remain very high after the X17 solar flare and associated CME. FOT MP will produce products today, to resume science after next perigee exit. There will be another radiation telecon at 5pm EST today to re-assess radiation and determine if a later time for science resumption is needed. A long-duration M4 flare occured several hours after the X17 flare, which might produce a CME. The discussion of the ACIS CTI measurement on the descending leg of this orbit produced the following conclusions: 1. the load being planned by FOT MP would allow an SCS107 run by RADMON trip due to the ACIS CTI measurement, without disturbing the possibility of resuming science at perigee exit. This is because the load is segmented such that the first maneuver and ACIS Stop Science commands are in the first SCS, and the next maneuver is immediately before science resumption, in the next SCS. Assuming the first maneuver executes correctly (before SCS107 and RADMON are enabled), then a SCS107 run from RADMON at the time of the ACIS CTI would stop all mission SCSs, but the remaining mission SCSs for the load could be re-enabled without problem. 2. Nonetheless, there will be a broader radiation team review and approval process for the planned ACIS CTI measurement, to consider the risk of running SCS107 against the benefit of the CTI measurement. The final go/nogo for the ACIS CTI will occur at 5am EST tomorrow. Oct 30, 2003 Shift Report ------------------------- 3-day Solar-Geophysical Forecast issued Oct 29 at 22:00 UTC Solar Activity Forecast: Solar activity is expected to continue at high levels. The very large and complex Region 486 will likely produce more major flare activity during its remaining 5-6 days on the visible disk. A major event is also possible from Region 488. Geophysical Activity Forecast: The geomagnetic field is expected to continue at severe storm levels through day one. The IMF Bz is now sustained southward at near -30 nT, resulting in severe storm levels. This condition is expected to persist through at least the first half of day one. A gradual decline to unsettled to minor storm levels is expected by day two. The potential geomagnetic impact from today's X10 flare will be assessed next period; predictions for days two and three will likely change considerably. The greater than 10 MeV proton event, currently in progress is expected to continue through day three. The greater than 100 MeV proton event will likely continue as high energy protons quickly stream in from the X10 flare that occurred late in the period. Oct 31, 2003 Shift Report ------------------------- The sun having broken out with a terrible case of acne all week, we finally got a chance to resume science. The ACIS team was particularly eager to get some solid CTI data after an X18 and X11 flare exhibiting a hard spectrum. Radiation in the EPHIN E1300 channel being high, but consistently below 1/3 of the trigger level, and all other radiation indications being benign, we decided to proceed. The COM was smooth, and the plan executed without surprises or problems.