Aug_13_1999_L22.txt Shift L22 (A22)
        Start at 1999:225:10:00 GMT = 1999 Aug 13 6:00am EDT
        End                           1999 Aug 13 2:00pm EDT

See http://asc.harvard.edu/acis/SOT_reports/sot-shift.html, or 
/proj/ascwww/AXAF/extra/science/htdocs/acis/SOT_reports/Aug_13_1999_L22.txt.
   
SOT Lead	Ed Kellogg
SOT SC/ACA	Mark Freeman
FOT-SI		
HRC-SI		James Reeves
ACIS-SI		Yousaf Butt

(Times will be given in GMT on day 225. not precise.)

EVENTS							PLAN	DONE	OBSID
--------------						----	----	-----
Start shift (06am EDT 13 Aug 1999)			1000	1000	62563
Gyro scale factor & misalignment SOP 6F003		ongo
Changed from Goldstone to Canberra				1124
LGA A to B							1147
ACIS radiation entry					1500
Finish SOP 6F003					1530	1310
End shift (2pm EDT 12 Aug)		day 225		1800	1853
Canberra LOS							1955
CAP 252 powers down earth sensors 
Goldstone AOS						2240
Start PCAD checkouts					2300
End radiation				day 226		0050
Start ACIS, SAP 61044					0100

NOTES/ISSUES/PROBLEMS 
--------------------- 

At H-to-L shift change, 225:1000, 

Chandra	10.5 hrs before perigee
ACA	in the Gyro scale factor & misalignment procedure
HRC	on, low voltage power only 
EPHIN	nominal
ACIS	Flight Contamination source Monitoring, looking at
whatever was in the field of view as we went through the scale factor
& misalignment procedure, which does a series of slews to various
locations on the sky, with a dwell and ACA lock on the stars, to give
data for updating the gyro scale factors and offsets.

As of 1220, spacecraft configuration: 

IU-A, CTU-A, RCTUs A Side, OBC-A Online, OBC-B Offline.
PCAD: VDE-A IOE-A, ADE-A, SPE-A/B, FSS-A/B, IRU-1 = LO, IRU-2 = LO.
Commanded attitude monitor enabled, 
Autonomous unloading & RW momentum bias disabled,
Momentum monitor fault safing action (SCS #9) disabled,
Auto transition to NPM function disabled (temporary)
Pointing is NMM sun pointed, 120 deg SA angle
Vacuum 4.5e-6 torr, 
Link via Canberra-DSN direct-512-LGA-B.

The gyro scale factor & misalignment procedure was completed
successfully. At the last maneuver back to normal sun mode, looking at
the South Ecliptic Pole, we acquired 6 out of a possible 8 stars in
ACA. For the 8 pointings done in this procedure, we got enough stars
on each occasion to expect a successful calculation.

While tracking stars, we also saw an instance of a cosmic ray hit that
caused the tracking box to shift over a bit. The ACA recovered quickly
and centered the star in the box again. This is an example of the
recovery behavior that we were certain exists when tracking stars,
but which is not as yet available when tracking fidlites.

At 2300, we plan to start PCAD checkout activities. These could be
done as early as 226:0300, 7 1/2 hours earlier than the planned start
of OFLS scheduled activities. We should be prepared to use that time
effectively.