From  Chandra X-ray Observatory Report 10/29/11
------------------------------------------------


The observing schedule was again halted at 12:58am EDT on Oct 26
by what was likely a single event upset (SEU) in the telemetry
processor of the Command and Telemetry Unit, causing a reset of its
timing signals and resets of several spacecraft components. An
elevated temperature of the aspect camera CCD due to the resets led to
its losing track of stars resulting in the spacecraft entering
normal-sun mode. All safing actions were nominal.

Recovery procedures were successfully executed Oct 26-27. The tasks
included: performing diagnostic dumps of the Control Processing
Electronics (CPE), re-synching the on-board computer clocks,
re-loading software patches to the aspect camera electronics, to the
science instrument module electronics, and to the EPHIN Input/Output
unit, resetting the aspect camera CCD temperature, patching the
ephemeris-time-offset K-constant in the flight software,
recovering to Normal-Point Mode, updating the on-board ephemeris, and
performing a momentum dump. 


From SOT Shift Report 10/26/11
------------------------------

Solar storm is subsiding and ACE rates are still decreasing.
Solar Activity Forecast: Solar activity is expected to be low with a 
slight chance for M-class activity all three days (26 - 28 October). 
Regions 1324 (N12W26) and 1330 (N08E29) are the most likely to produce 
moderate level activity. 

UTC 2011:299:12:50:08 (Oct26) f_ACE 3.59e+03 F_CRM 2.63e+08 Kp 3.3 R km 143332A

                    Currently scheduled FPSI, OTG : HRC-S NONE
                                     Estimated Kp : 3.33
        ACE EPAM P3 Proton Flux (p/cm^2-s-sr-MeV) : 3.59e+03
           GOES-15 P2 flux, in RADMON P4GM  units : 0.88
           GOES-13 P2 flux, in RADMON P4GM  units : 0.72
           GOES-15 P5 flux, in RADMON P41GM units : 0.13
           GOES-13 P5 flux, in RADMON P41GM units : 0.19
           GOES-13 E > 2.0 MeV flux (p/cm^2-s-sr) : 0.0
                                 Orbit Start Time : 2011:298:13:44:01
              Geocentric Distance (km), Orbit Leg : 143302 A
                                       CRM Region : 2 (Magnetosheath)
           External Proton Flux (p/cm^2-s-sr-MeV) : 7.3831e+03
         Attenuated Proton Flux (p/cm^2-s-sr-MeV) : 0.0000e+00
  External Proton Orbital Fluence (p/cm^2-sr-MeV) : 1.2767e+09
Attenuated Proton Orbital Fluence (p/cm^2-sr-MeV) : 2.6321e+08


From SOT Shift Report 10/27/11
------------------------------

Radiation quiet.
Solar Activity Forecast: Solar activity is expected to be low with a 
slight chance for M-class activity all three days (27 - 29 October). 
UTC 2011:300:13:14:01 (Oct27) f_ACE 4.84e+02 F_CRM 2.63e+08 Kp 3.3 R km 124762D

                    Currently scheduled FPSI, OTG : HRC-S NONE
                                     Estimated Kp : 3.33
        ACE EPAM P3 Proton Flux (p/cm^2-s-sr-MeV) : 4.38e+02
           GOES-15 P2 flux, in RADMON P4GM  units : 0.48
           GOES-13 P2 flux, in RADMON P4GM  units : 0.64
           GOES-15 P5 flux, in RADMON P41GM units : 0.19
           GOES-13 P5 flux, in RADMON P41GM units : 0.21
           GOES-13 E > 2.0 MeV flux (p/cm^2-s-sr) : 6.0
                                 Orbit Start Time : 2011:298:13:44:01
              Geocentric Distance (km), Orbit Leg : 125052 D
                                       CRM Region : 2 (Magnetosheath)
           External Proton Flux (p/cm^2-s-sr-MeV) : 6.2131e+03
         Attenuated Proton Flux (p/cm^2-s-sr-MeV) : 0.0000e+00
  External Proton Orbital Fluence (p/cm^2-sr-MeV) : 1.6118e+09
Attenuated Proton Orbital Fluence (p/cm^2-sr-MeV) : 2.6321e+08