SOHO SPWG Minutes


SPWG MEETING MINUTES, TUESDAY, JUNE 24 1997



Chair:		Bernhard Fleck (ESA)
Notes:		Robert Doney (NASA/SOC)
Present:	Joe Covington (MDI), Craig DeForest (MDI), Andrzej Fludra (CDS),
		Rai Wu (UVCS), Jeff Newmark (EIT), Don Michels (LASCO/EIT), 
		Dan Moses (LASCO/EIT), Harold Benefield (FOT)


NOTE:   The SWT for July has been cancelled.  The next SWT will be 
	October 15,16 at GSFC.



1.	Review of action items:

        97_2.2  Action on EIT to provide SOC information concerning desired
                EIT offpointing in the next 6 months. 

	STATUS: (postponed) 
	No offpointing will take place during the September
	maneuvers.  EIT will propose new offpointing information in the
	near future.

	97_5.1  Inputs for Roll Maneuver in September.  The roll maneuver
	has been rescheduled to September 2-5
	(see section 3)


2. 	Boundary conditions for the coming month
        - MDI Continuous: until July 13

	August 1: 6 hours SVM Reserved for Memory Dump and Tape Recorder
	Maintenance.


3.	Preview of future months
	A large amount of coordinated observations has been announced for
       	July. Teams are requested to set priorities well in advance, if 
       	needed. For the latest calendar update, see:


		http://sohowww.nascom.nasa.gov/~soc/head_calendar.html

        - September maneuver, roll, station keeping, and thermal readjustment


        September Maneuver
        ~~~~~~~~~~~~~~~~~~
         Originally 10-13 Sept
           - ACE Launch 21 Aug
           - ACE Maneuver 6-10 Sept

         Alternate Dates
           - 29 July-1 Aug
                -- Ranging Data
           - 2-5 Sept  (better date)

         o Still including Roll Maneuver (+90 degrees)
         o Duty cycle adjustment on FPSS Baseplate

        Maneuver Sequence
        ~~~~~~~~~~~~~~~~~
        Day 1:  Gyro Calibration
        Day 2:  Momentum Management
                   - for Roll Maneuver
        Day 3:  Roll Maneuver
                     +90 degrees
                   - ~16 hour duration of roll
			(maximum amount dictated by constraint)
                   - stop at 45 degrees for 15 minute dwell (MDI/EIT)
        Day 4:  RW 4 Maintenance
                   Momentum Management, Station Keeping: ~ 2 m/s => 15-20 min burn
                        no fuel estimate as yet, but it will be considerable


        Long Term Issues
        ~~~~~~~~~~~~~~~~
        o Momentum Management/Station Keeping to be on 4-5 month cycle
        o Roll maneuver every 6 months will be out of sync:
                - Will require additional gyro activity
        o Next MDI 3 month continuous to start in January
        o Following maneuver in January (wheel speeds are tolerable into
                February following the September maneuver)
        o Roll maneuver in March during MDI continuous? (MDI cannot
                tolerate a roll during continuous)


4. 	Priorities for the coming month

	All instruments nominal.

	Additional Notes:
	~~~~~~~~~~~~~~~~~
	CDS: Cannot participate in the Type 1 Radio Burst study on 
	      July 11

	MDI: There will be La Palma observations beginning July 23,24
	      and lasting for about 1 week.


5.	JOPs status  
          - Input to campaign catalog is satisfactory
	  - JOP003, Coronal Mass Ejection Onset,  dates may be refined 
		in the coming weeks.
	
6.	New JOPs
	  - Number not yet assigned: Coronal Hole Flows
          - JOP 066,  Loop Fine Structures, Giovanni Peres
	  - ICAL 12, SOHO/SEH-2/CALSO-3 Cross Calibration, Don McMullin 
       
			SOHO Intercalibration 13

				EIT CalRoc

	Objective: Improved EIT flatfield and absolute calibration

	Approach: The EIT space optics have been incorporated into a 
	sounding rocket payload.  This instrument has been calibrated with the full
	program which was planned for the SOHO EIT (but truncated by 
	programmatics).  Further calibration checks will be applied immediately
	before and after launch.

	COORDINATED OBSERVATIONS:

	1) ICAL 12, SOHO/SEH-2/CALSO-3 Cross Calibration, Don McMullin
	2) CDS Full Sun observing program 

7.	AOB

	- Date for July SPWG:	Friday, July 25
	- Date for next SWT:	October 15, 16 GSFC