Interim ACIS Shift report A July 25 1999.

The first Chandra vacuum monitor reading settled out at around 
1.2E-4  torr.

There has been some discussion of commanding ACIS focal plane to
a lower temperature.  Currently it's commanded to a nominal -120C,
which produces an actual setpoint of -120.6.  The following temps
represent the commandable actual setpoints between the current value 
and -129C:
	-121.7	-122.9	-124.0	-125.2	-126.3	-127.5	-128.6

These numbers supercede the ones reported in Paul's previous email.

Solar array characterization and the next earth scan proceeded on
schedule.

Perigee at 002:09:02

ACIS personnel discussed the situation at 7 am EST (Dan Schwartz,
Mark Bautz, Ellen Sen, Royce Buehler) and decided to create two
more focal plane temperature setpoint commands: one to -126.3, and one
to -121.7. Bob Goeke advised against commanding any temp other than
-120.6 until after the big vent valve opens; residual gas in the ACIS 
chamber could well be the reason for the elevated temp we've been seeing.

----------------------------------------------------------
Temperatures this shift? Let's do the numbers:

MET             FP Temp 1CRAT   1CRBT   1WRAT   1WRBT   1CBAT   1CBBT

001:21:50               -127.9  -127.9  -82.0   -82.0   -62.4   -59.9
71578km

001:22:19       -118.9  -127.9  -127.9  -82.0   -82.0   -62.4   -59.9
71178km

002:01:05               -127.9  -127.9  -82.0   -82.0   -62.4   -59.9
65000km

002:02:26               -127.9  -127.9  -82.0   -82.0   -62.4   -59.9
60000km

Royce relieved Paul at MET 2:02:40.

002:03:16		-127.9	-127.9	-82.0	-84.4	-62.4	-59.9
56400km
002:04:19		-127.9	-127.9	-82.0	-82.0	-62.4	-59.9
50440km
002:04:33	-118.9	-127.9	-127.9	-82.0	-82.0	-62.4	-59.9
49000km
002:05:22		-127.9	-127.9	-82.0	-82.0	-62.4	-59.9
43100km
002:06:25		-127.9	-127.9	-82.0	-82.0	-62.4	-59.9
? km
002:06:43		-125.5	-125.5	-82.0	-82.0	-62.4	-59.9
31096km
   Happened to be watching just as the first tick away from -127.9
	occurred.
002:07:00		-125.5	-125.5	-82.0	-82.0	-62.4	-59.9	
28150km
002:07:20		-125.5	-125.5	-82.0	-82.0	-62.4	-59.9		~24000km
002:07:40		-125.5	-123.1	-82.0	-82.0	-62.4	-59.9
20150km
002:08:00		-125.5	-123.1	-82.0	-82.0	-62.4	-59.9
10900 km (verbal from Orbit)
002:08:20		-125.5	-125.5	-82.0	-82.0	-62.4	-59.9
10600km	
002:08:25 - data gone.  LOS from Goldstone due in another 15 minutes		
Perigee at 002:09:02

Ellen Sen relieved at MET 2:08:40

submitted by
Paul Plucinsky, Royce Buehler