May 22, Telecom --------------- SCS-107 ran at ~2013:142:14:49z due to high radiation. The OBC RadMon telemetry did not show the last-held HRC or EPHIN at their threshold values which suggests that this was the first instance of an ACIS initiated trigger. (see https://cxc.cfa.harvard.edu/mta_days/mta_interrupt/Extra/20130522-acis.gif) SCS-107 ran nominally. Clean-up actions will be taken to disable SCS-29 and change the ObsID. Plan A for recovery is to resume on day 144 after the radiation zone passage. The schedule will be reworked to include the scheduled ToO of CXOU J072648.3+854549 and the planned observation of Sgr A* that will be missed. Start of observing may begin after the first comm-pass following rad-zone Shift Report (May 23, 2013) --------------------------- Radiation: A partial halo CME was observed in LASCO imagery after the M5 event in AR 11745. Earth could receive a glancing blow on May 24/25. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to active levels on day one (23 May), quiet to unsettled levels on day two (24 May) and quiet to active levels on day three (25 May). Protons are expected to cross threshold on days one and two (23 May, 24 May) and are likely to cross threshold on day three (25 May). Solar Activity Forecast: Solar activity is expected to be low with a chance for M-class flares and a slight chance for an X-class flare on days one, two, and three (23 May, 24 May, 25 May). Chandra X-ray Observatory Report (May 24, 2013) ------------------------------------------------ During the last week Chandra the observing schedule was interrupted by a high-radiation event that activated the science instrument safing sequence (SCS 107) and stopped observing at 10:49am on May 22. All spacecraft actions were nominal. Real-time procedures were executed on May 22 to disable SCS-29, which was enabled during the safing sequence, and to update the observation identifier number, to aid CXCDS processing of the interrupted observation. A real-time procedure was executed on May 24 to verify that the radiation environment as observed by the HRC anticoincidence shield had decreased to an acceptable level. Loads for a replanned schedule were uplinked on May 24 with 121.9ks of science loss. Observations that were impacted will be rescheduled.