UVIS TEAM MEETING OPERATIONS UPDATE 6/8/09 UVIS TEAM MEETING

Instrument Status On/Off Cycle: 27 Hours On: ~77,500 hours No change since last meeting Hours On: ~77,500 hours Continuous operations since 9/11/2007 Longest continuous operations was from 1/15/2005 (probe relay) to 9/11/2007 (S/C safing) HDAC Filament Modulation: Filament 1: 100.28 hours Filament 2: 12.22 hours Last: 2006/255 6/8/09 UVIS TEAM MEETING OPERATIONS UPDATE

AI from last meeting #1 Can we run HSP at 0.5 mlls? Closed (1/16/09) The answer is NO: As documented in logic design document. As tested on the EM. 6/8/09 UVIS TEAM MEETING OPERATIONS UPDATE

AI from last meeting #2 Off axis Titan occultation under RCS Closed (1/27/09) Unfortunately I put the offset on the wrong axis in my email to Bob Proposed pointing and instrument setup UVIS_FUV to star with (-1.375, 0.0,0.0) offset HDAC.ON=NO, HSP.ON=NO, FUV.ON=YES, FUV.COMP=SQRT9, FUV.INT=1.75, FUV.SLIT=OCCULT, FUV.N_OF_WIN=1, FUV.WIN1=1,1024,1,54,58,1, EUV.ON=YES, EUV.COMP=SQRT9, EUV.INT=5.0, EUV.OCCULT=CLOSE, EUV.SLIT=OCCULT, EUV.N_OF_WIN=1, EUV.WIN1=1,1024,1,55,59,1 We have a test of this configuration scheduled in S54 6/8/09 UVIS TEAM MEETING OPERATIONS UPDATE

Significant Issues S47 UVIS_102RI_ALPARAOCC001_VIMS UVIS_102RI_VENCUNMP001_CIRS Data loss due to weather S48 Sequence de-activated during thruster branch swap activity (071T02:10 to 077T03:05) No data during this period S49 UVIS_109TI_FIRNADCMP001_CIRS UVIS_110SW_IPHSURVEY002_RIDER UVIS_110EN_ICYATM00 & UVIS_110SW_IPHSURVEY003_RIDER Data loss due DSS 14 red S50 UVIS_110SA_MOS110APO003_PRIME 6/8/09 UVIS TEAM MEETING OPERATIONS UPDATE

Titan Occultation under RCS S49 (T53) UVIS_107ST_ALPERITI001_PRIME 0.5 mrd deadband Tightening of the walking deadband 3 steps of .12 mrad Max deviation is .86 mrd per axis. First part (no shown) has star in/out of the slit S50 (T56) UVIS_112ST_ETAUMATI001_PRINE During transition from RCS Not on the ground yet 6/8/09 UVIS TEAM MEETING OPERATIONS UPDATE

RBOT Process UVIS Statistics: S50: 5 out of 18 S51: 7 out of 21 S52: 0 out of 3 S53: 2 out of 3 The process is improving at each sequence. 6/8/09 UVIS TEAM MEETING OPERATIONS UPDATE

Planning/Scheduling Notes We are starting to flight sequences without a final DSN allocation. Use UVIS_SOLAR_OFF to Sun in CIMS for all solar occulation (starting S54) instead of ISS_NAC to Sun (-20.0, 0.0, -0.11 deg) offset. The list of ring occultations that contain an atmospheric occulation is on the team web site at http://lasp.colorado.edu/cassini/team-site/archive/docs/pdf/Atmospheric_Occ.pdf 6/8/09 UVIS TEAM MEETING OPERATIONS UPDATE

Concerns What do we have to do in order to still have a usable instrument in 2017? HSP is degrading The burn area in the FUV is getting deeper and wider Turn off HVPS when FUV and EUV not in used for more than ??? hours? Switch to the HI_RES slit if FUV and EUV not in used for more that ??? Hours? 6/8/09 UVIS TEAM MEETING OPERATIONS UPDATE

Ops team status for reminder of 09 Getting better now that KEPLER commissioning has concluded. Still one instrument launch this year: EVE on SDO (November). The launch of the TIM instrument on Glory has been delayed (2010, 2011?). So we are breathing a little better. EVE: EUV Variability Experiment - SDO: Solar Dynamic Observatory. TIM: Total Irradiance Monitor. 6/8/09 UVIS TEAM MEETING OPERATIONS UPDATE