Recovery from safety circuit trip

Location

Purpose

Steps to run

1. Check if the ICU is in BASIC state (possible watchdog trip). If so, run procedure for recovery from watchdog trip before returning to this procedure.
2. Check if the trip was during a slew. If so ask the FOT to dump VC07 for 5 min before and 5 min after the trip and email Phil to consider editing istandard.proc to increase the safety circuit parameter for slews. Check the *_att.log files to get the r.a. and dec. at the time of the trip (trip time is found in *_icuevents.log files). Check for bright sources (brighter than mag 4 and very blue) with a star atlas or SIMBAD (ask the current ODS if necessary). Write an anomaly report or email Phil details for an anomaly report. Check for similar slews: The PPST is available on the MOC web page and can be checked by the UDS. Remember the preplanned timeline is only an estimate and is overridden by GRBs and TOOs. (If there are GRBs TOOs active, these will override the PPST: if not sure contact the current ODS.) If similar slews may occur again, contact the ODS and let the ODS choose if it is worth going to IDLE and having another possible trip or waiting until the next commanding period and increasing the safety circuit parameter first. Normally it is OK to try again once to make sure it wasn't just bad luck.
3. Check if the trip was during a grism exposure. If so, email Phil to consider getting the safety circuit parameters changed in the uvotmodes. You can goto IDLE and try again but the same field will probably do the same until the AT or PT table is changed unless the Earth angle was contributing: this is then the choice of the ODS depending on the importance of the observations. Normally it is OK to try again once to make sure it wasn't just bad luck.
4. If the trip was when settling or settled, check for bright sources with SIMBAD (tell ODS if necessary so that the ODS can tell the planner). This is particularly important if the safety circuit trip is near the start of the exposure as the cause could well be a bright source.
5. If the trip was in the middle of an exposure (i.e. not in the first few seconds) then it likely that is was an "unexplained" trip caused by an unexplained flash lasting longer than 1.3 s.
6. If necessary, Wait for a MAL pass to get enough data.
7. Check the high voltage values for a few minutes before the trip to check they were healthy. Check the Spacecraft voltage to see if the Spacecraft was in Sunlight. Check the last RateOp before the trip. Check the Earth/Moon/Sun angles. Check the filter.
8. Talk to Barry as this is an electronic circuit and Phil as he has investigated more trips than anyone.
9. When the cause is understood (remember the preplanned timeline is only an estimate and is overridden by GRBs and TOOs), recover by running:

   start icu_tdrsshk_on(100)
   

   (icu_tdrsshk_on can be delayed until the end of these commands, exspecially when in a MAL contact)

   start icu_idle
   

   (answer the questions correctly).

   start icu_errors_reset