Shanil Virani email from 01/09/04 05:18 AM Our 2 hr ACE fluence monitor (derived from FP6p) has just went off. Chandra is currently at 118496 km and descending. In fact, we have only ~12.5 hrs before the SIM translation to HRC-S for perigee transit at 009:22:22:25 UT. We also only have 1 COMM opportunity between now and the SIM translation and that occurs in 3.5 hrs from now (COMM: 08:30 to 09:30 EST). At the last COMM pass (just over an hour ago), the EPHIN E1300, P4 and P41 channels were all well below their SCS107 trip values (readings: 0.03, 1.81, and 0.00, respectively). The current ACE FP6p reading is 613 which means the P3-derived flux is 22068 (=613*36). Which means an additional fluence of ~9e8 on top of our current fluence for the orbit of 3e8. So our total orbital exposure would be around 1.2e9 for the orbit if the ACE P3 fluxes do not get any higher. The ACE P3 flux would have to average ~70,000 over the next 12.5 hrs to have a total ACE p3 orbital fluence of 3e9. Lastly, while the GOES P2 rates have started climbing (our proxy for the EPHIN P4 channel), they are still ~ 2 orders of magnitude below the EPHIN P4 trip value. Therefore, I don't think there is any need to intervene at the next COMM unless the situation deteriorates rapidly between now and the 0830 EST COMM pass this morning. Of course the situation bears watching between now and the SIM translation at 22:22 UT later today and of course on egress from perigee at 010:14:32 UT. Jna 09, 2004 Shift Report -------------------------- Radiation Discussion Summary 9:15am, 1/9/2004: SCS-107 commanded at 009/1345UT due to high radiation. Maneuver needed before tomorrow morning to avoid earth violation at 010/0712 Uplink maneuver load during either 009/2310 or 010/0250 passes. 3-day Solar-Geophysical Forecast issued Jan 8 at 22:00 UTC Solar Activity Forecast: Solar activity is expected to be moderate for 09-11 January with Regions 536 and 537 being the most likely source for activity. There continues to be a slight chance for a major flare or proton producing flare from either of these regions during the 09-11 January forecast period. Geophysical Activity Forecast: The geomagnetic field is expected to be generally unsettled for 09-11 January with a slight chance for isolated active periods.