Minutes SOHO Weekly Planning Meeting January 26, 1996 Chair: Piet Martens, ESA SOC Minutes: Bernhard Fleck, ESA DPS Handout distributed (more copies can be obtained upon request) 1. Long Term Schedule (Feb 8 - March) - Halo Orbit Insertion now planned for Feb 14, due to fuel budget and DSN availability. TBC by ESA and MATRA. - Additional S/C activities for March: a) Final commissioning (4-5 days) b) Software patches (approx. 1 week) - Updated schedule appended 2. Constraints related to S/C / Experiments pointing commissioning tests - see handout for details - For absolute pointing test (S6): no experiment motions, except those required to take images - For "jitter" test (S9): motions only as timelined for jitter measurements, plus those for taking images - For thermo-elasticity test (SSP2): same as S6, plus no activities that may affect thermal balance. i) S6 / J5 Absolute Pointing Calibration - discussion about Matra test requirement for instruments to go back to ground reference position; this is not possible for several instruments (requires several weeks of fine tuning for LASCO to go back to normal observing position); besides the difference between the ground reference position and the present in-flight one is very well known for all except UVCS, so test results can be reduced to ground reference. Maryse Hervieux to inform Matra experts and resolve issue. ii) S8 Pointing stability - Movements required to provide pointing data + precision of pointing data: MDI: focus + shutter movements; sun center on CCD to a few 10th of arcsec; roll not as precise CDS: after sun sensor calibration no movements necessary; no roll info; several arcsec precision SUMER: few arcsec sun center; no roll info; jitter to 1"; no movements EIT: shutter, sector wheel; accuracy: 1.3" LASCO: shutter, sun center to 5" in LASCO image, roll to 1 arcmin UVCS: 1.5 arcmin to cube; 15" in pitch an yaw; roll to 1 arcmin; no movements if done using sunsensor alone; for coregistration also internal movements (occulter etc.) iii) S9/ J4 Pointing stability - Movements during normal mission which could induce jitter: MDI: shutter, Michelson tuning motors, cal-focus wheels CDS: legs, slit, folding mirror SUMER: grating focus scan mirror, telescope mirror, slits EIT: sector wheel, shutter, filter wheel UVCS: roll mechanism, pointing mechanism, telescope mirrors, internal occulters, gratings, polarizer mechanism, filters LASCO: shutters, filter wheels, polarizers (all for C1, C2, C3) SWAN: periscope mechanisms - CDS won't be ready when this test is done first time. Jitter test done only once; Piet Martens to contact Richard Harrison to resolve issue. Matra will check if CDS is required to participate. iv) SSP2 PTCS calibration v) J1 Rolls calibration vi) J2/J3 S/C oscillations and off-pointing for GOLF and VIRGO/MDI ---> constraints on these three TBD jointly by experimenters 3. Medium Term Schedule - DSN contacts: mostly regular next week, i.e. ~ 8 hours experiment activity; extra time will mainly be used by FOT for S/C activities; DSN plan can be retrieved electronically from ECS WS. Output from IDL planning tool available on Web now, includes DSN schedule. Experiments encouraged to start providing IAP's for inclusion in schedule. Normal ops planning system needs to be functional after HOI. - experiments needs for dedicated copmmand link: MDI: leg motions to point to south pole (20 motions over 5 h, several minutes NRT-d each) SUMER: none CDS: no request for dedicated, but like priority for most commissioning activities EIT: no need for dedicated time UVCS: priority for calibration of Sun sensor early next week SWAN: no need CELIAS: nothing identified at present time - no changes of telemetry submode planned - MDI south pole campaign to be coordinated with other instruments (EIT, SUMER, UVCS); Craig DeForest to organize joint observations 4. AOB - Key cards need to be returned to Kim or Jean prior to long absence from GSFC. Recently Jean had to cancel 17 keycards that had been were out of use too long. Art Poland to resolve issue. John Kohl asks whether other methods would be feasible, like revalidation of cards after absence. Referred to Art. - Julia Saba will take action to get draft letter to acknowledge excellent support by FOT Next meeting: Friday, February 2, 14:00 EDT at EOF ____________________________________ APPENDIX SOHO COMMISSIONING SCHEDULE - LONG TERM The following draft schedule has been set up by Maryse Hervieux and myself in response to the opportunity for performing Halo Orbit Insertion on February 14, 1996. Piet Martens 25 January Feb 8 - Feb 26: Halo Orbit Insertion, Halo Orbit Commissioning S/C and Experiment Pointing Tests TEST - DESCRIPTION - DURATION - TIMELINE S6/J5 - Absolute Pointing Calibration 0.5 day - 8 Feb (12h pass for S9/J4 - Pointing Stability 0.5 day - 8 Feb both on one day) (includes S8) SSP2 - PTCS Calibration for Pointing 4.5 days - 9-13 Feb - Experiments to Safe 2h - 13 Feb HOI - Halo Orbit Insertion Maneuver 1 day - 14 Feb (12h hot backup) Mom - Momentum Management + Contingency 1 day - 15 Feb NEAR - NEAR Launch (reduced DSN) 1 day - 16 Feb - Experiments reopen doors 5h - 17 Feb Cal. - Experiment Cal. on 38 Aqr. 1 day - 18 Feb SSA6 - GOLF SSPS Off-set Calibration 3 days - 19-22 Feb (continue during non-contact) ___________________________________ March timeframe (depending upon DSN availability) AOCS - S/W Patches and Tests 1 week J1 - Calibration Rolls 1 day (momentum management) SSA6 - MDI, VIRGO SSPS Off-set Cal. 2 days (extended contacts) - HOI Commissioning (tests TBC) 5 days SSA9 - 4th Reaction Wheel Test 4h (Hot Backup) MDI - 80h continuous test 3.5 days (continuous contact)