OSIRIS Horst Uwe Keller and the OSIRIS Team M42 Orion Nebula colour composite Horst Uwe Keller and the OSIRIS Team 26. Rosetta SWT – 11./12. June 2009 at ESTEC Max-Planck-Institut für Sonnensystemforschung

OSIRIS Team Activities Team status Recent OSIRIS operations Support of PC9 Instrument status Shutter MRB support Safe mode observed at Steins NAC functional problems Resulting ongoing actions Onboard S/W extensions to improve exception handling Onboard S/W code review in co-operation with IDA Presentation of Steins results at Spring AGU mtg. in Toronto OSIRIS

Team Status New Co-Investigator: Monica Lazzarin (University of Padua, Italy) OSIRIS

Activities Since Last SWT PC9 Passive Checkout (nominal) Two interactive passes in March 2009 used to test a root cause hypothesis for the NAC shutter problem OSIRIS

Shutter Performance Analysis Team-wide detailed investigation (review) still ongoing (lead H. Sierks) detailed ab initio analysis of shutter properties and behaviour: mechanics and operations s/w Support of ESTEC mechanism department Goal to demonstrate performance during last upcoming Earth fly-by OSIRIS

NAC shutter NAC shutter issues seem to comprise 3 related anomalies: 1. The NAC shutter safe mode condition triggered at Steins 2. The NAC functional problems observed at Steins 3. The NAC performance problem OSIRIS

NAC shutter safe mode Preliminary analysis of NAC safe mode at Steins confirmed The failure was caused by a timing issue that was not taken into account by the s/w and caused the shutter electronics FPGA to report a wrong hardware state because the state changed after the relevant encoder to readout The failure mechanism is now understood A modified IFSW shutter error handling module is ready for uplink OSIRIS

NAC functional anomaly The MRB investigations point to a single deficiency causing the locking problems of the NAC shutter (preliminary) It seems that the “home” (starting) position of the shutter blades is not well defined A cure is straight forward by an extra push before the actual image exposure This is being tested Impact on operations is a reduction of image repetition rate, about 1.2 s of extra latency are needed ESTEC 10./11. 6. 2009 OSIRIS

NAC performance Uncertainty of exposure time due to opening between shutter blades during back travel Can be solved by use of the “back travel brake” additional hardware introduced shortly before launch functional application successfully tested safe operational handling still being commissioned (looks very promising) OSIRIS

Onboard S/W Extensions to allow better exception handling have been developed Implementation of the home push Code review in collaboration with IDA S/W update expected during PC10 OSIRIS

Future Activities Upcoming activities Unchanged since last SWT PC10 ESB3 It is very likely that we will update IFSW in connection with PC10 Unchanged since last SWT Plain file handling (implement sequences for simple handling) Autonomous action on SREM particle flow implemented and tested, but not enabled as threshold is to be tuned EPS (Experiment Planning System) modeling out of sync with OSIRIS flight software (Input to SOC delivered) OSIRIS