Radiation Telecom (03/17/2013) ------------------------------- Prior to the 076:1145-1245 pass the ACE P3 rate had come down from its sharp peak but were still at 50,000-60,000. If we remained at this rate until the next comm the orbital fluence for ACIS would be exceeded. The HRC rates observed for the ongoing Crab TOO are near the expected level. The decision was made to use CAP 593A to activate SCS 107 and safe the SIs starting at 12:30 UT to get as much of the Crab time as possible. SCS-107 ran nominally. The plan is to attempt a resumption of observing at the next Rad-zone exit ~078:05:35 UT using the as-planned activities. The ACIS team is considering the possibility of starting a long ECS measurement via CAP at the 076:2015-2115 comm pass (4:15-5:15pm EDT). Mar 18, Shift Report --------------------- very soft radiation event peaked at 200,000 Sunday monring leading to Manual shutdown Sunday 2013:076:12:32. Science restart planned for 2013:078:05:59:10 Forcast is for 20% chance of additional M flares today and tomorrow. 0600 UT day 076 We just had a telecon since the ACE 2 hour fluence alert tripped. ACE P3 rates have increased from 24,000 to 155,000 in the last 2 hours. Fortunately, the HRC is currently in focus and will be in focus until 11:07am local time. ACIS next goes back into focus at 11:07am local time. Because of this, we decided that we shall reconvene at 7:30am to review the situation at the start of the next COM. The ACE fluence for the orbit currently stands at 6.3e+8 and is not increasing since the HRC is in focus. If rates are still high when ACIS goes in, the 1e+9 fluence limit will be reached quickly.