UVCS MISSION LOG
				----------------

	Date:		07 February 2002
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 	Last revision:	12 February 2002 (Wu)
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	File Name: 	2002.02.08.a.log
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	Compiled by:	M. Uzzo, R. Wu
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	UVCS Activity:	UVCS in Safe Configuration following Recovery
	--------------

	SOHO Activity:	SOHO MM/SK followed by return to normal mode.
	--------------	(For Additional Details, See Below)

	From email from SOC at Wed, 6 Feb 2002 14:30:04 +0000 (GMT):
	------------------------------------------------------------
	The station keeping and momentum management maneuver has been performed
	successfully, and the spacecraft is in Normal Mode since 17:56 UT. SWAN
	has been recovered from the maneuver safing mode.

	A timeline of instrument events and current plans can be found at this
	URL: http://sohowww.nascom.nasa.gov/soc/timeline_feb2002

	We are having an unexpected issue on board the spacecraft as well: 

	During last night, one of the FOT console crew members noticed that 
	some of the experiment LCL status mnemonics toggled to the unexpected 
	state, and then back to the expected state in the next format (15sec).

	It appears that, starting about 18 hours after the ESR, groups of LCL  
	status words started switching like this, in unison. The group members
	change from one time to the next. The corresponding currents toggle
	synchronously.

	This happens for all instruments, all LCL's (prime and redundant),
	regardless of whether the "expected state" is on or off.

	We know this can't be real since instruments are not being turned on 
	and off! In fact, nothing indicates that it is a physical switching.
	Therefore, it must be a data acquisition and/or handling problem, most
	likely related to the PLM RTU (payload module remote terminal unit), or
	its bus. It is only visible for the instruments.

	If it becomes a problem, the FOT may be directed to switch to the
	redundant PLM RTU. This may cause a synchronization problem, and you 
	may want to have the OBT redistributed to you.

	If, in the unlikely event of a switch, you would like to have any
	contingency scripts run before or after the switch, or any action done 
	by the SOCs (including rapid notification), or the OBT distributed to 
	your instrument, please notify us.

	Normally, if a relay is shown in the "unexpected state" for 3 formats, 
	it is being acted on as follows, depending on the expected state:

  	expected state on: Corresponding instrument is turned off (+subst htr)
  	expected state off: Thermal reconfiguration

	At this time, these corrective actions have been disabled to prevent 
	any unnecessary actions. Also, thermal reconfigurations due to red
	temperatures have been left disabled since the warm startup. (We are 
	in contact and actions would be decided in real time if a red limit is
	reached).

	The following message is from Helmut's report on SOHO status, from 
	this morning:

	----------------------------------------------------------------------
	Subject: SOHO ESR-18, day 3 (Feb. 7)

	The ESR recovery proceeds smoothly.

	While in CRP, random wheel torque demand errors occurred, which 
	disappeared after a while. A quick analysis lead to the assumption, 
	that the cause was the CRP controller rather than the wheels 
	(investigation will continue). We transitioned to RMW and continued 
	with instrument activation. So far, all instruments are on, except 
	SUMER and CEPAC.

	The activation of CELIAS showed, that the instrument did not lose the
	data, supported by the KAL's (Keep Alive Lines). The KALs are powered 
	by the auxiliary converter in the PDU, which in turn is connected 
	directly to the main bus. The context memory in the RMS 
	(Reconfiguration Module SOHO) of the data handling computer, supplied 
	via a FCL (Foldback Current Limiter), was intact also. We are checking 
	now, how other users of the FCL's and KAL's were effected by the main 
	bus drop.
	----------------------------------------------------------------------

	The following message is from Helmut's report on SOHO status, from this
	afternoon:

	----------------------------------------------------------------------
	Subject: SOHO ESR-18 final day (Feb.8)

	The spacecraft is back in Normal Mode. The instruments are powered-on 
	with the exception of CEPAC and SUMER, which will follow Tuesday, Feb.
	12.  Some telemetry samples from the Payload RTU are being corrupted 
	randomly (once every 30 minutes max.),  starting about 4 hours after 
	the RTU has been switched back to the prime branch. We set up 
	observation criteria for an alert by the console crew, should the TM 
	corruptions increase over the week-end.

	EOF Staff:	Y.-K. Ko: Lead Scientist, Planner (Science)
	----------	M. Uzzo: Commander, Planner (Operations)
			R. Wu

	Command file:	No Commanding

	Activity:
	---------

	1) UVCS Safe Configuration

	Sequence: 

	SCI_SPEC: UVCS not observing, Soft safe configuration 
		  (High Voltage Off & Door open)
		  
	OBS_PROG: 

	SCI_OBJ:  

	OBJ:      

	CMP_NAME:

	CMP_NUM:

	Duration: start: 2002.02.07.21:57
		    end: 2002.02.11.17:49

	ONUMs = NONE

	Instrument configuration:

		- Pointing:  Sun center

		- Roll: 86 Degrees

		- Mirror/Occulter: 1.5 Ro
 				   1.5 mm overocculting

		- LYA Slits:   50 um
		- OVI Slits:  100 um

		- LYA GRTPOS: 128000
		- OVI GRTPOS: 128000
		
		- LYA HIGH VOLTAGE RAMPED DOWN AND POWERED OFF
		- OVI HIGH VOLTAGE RAMPED DOWN AND POWERED OFF
		- VLD HIGH VOLTAGE RAMPED DOWN AND POWERED OFF

		- LYA mask:   NONE
		- OVI mask:   NONE