Shift report A11 August 2 1999, 8:00am EDT, GMT 214:12:00

ACIS Activities this Shift

1. Event Histogram Mode on the S array
2. Internal Cal Source Measurement for the FOURTH TIME !!!!!

Spacecraft Activities

- IPS burn 4 postponed !!!  Upon further analysis the propulsion and
fligth dynamics folks have concluded that the prime engines (LAE 1 and
LAE 3 ) did not function as expected.  The apogee is now 139,113 km
and the target was 140,002 km.  Now that may not seem like a lot but
our final orbit is carefully designed to minimize the length of earth
eclipses.  Yesterday, it was reported that 2 RTDs failed on LAE 1 and
LAE 3.  This is not a huge problem since there are 8 RTDs per engine
and it was originally thought that we could keep using these engines
for IPS #4.  But after the perigee shortfall, it was decided that we
should switch to LAE 2 and 4.  Unfortunately, there was not enough
time to upload the necessary patches to switch the engines before the
burn. So, we go around the earth again !!! Another 60 hours for
science data !!!

- HRC tried to ramp up their high voltage again at about GMT 214:04:00
but the count rates were still too high.  We put ACIS into Event
Histogram mode during this time and then pounced on the FMT 2 time
later.

OCC activiities

- there was a planned POWER OUTTAGE from 3am to 4:30am to repair some
of the electrical equipment in the building.  The OCC facility didn't
miss a beat, we failed over to the generator and all flight critical
computer systems were unaffected.  We lost the stella machine in the
ACIS room but the gorton machine stayed up.  The video switching box
on the SGI machine went down because it was on building power.  This
caused the SGI display to get stuck in power-saver mode.  Gary
V. switched the video box to secure power and all was well.


1. Event Histogram Mode on the S array

FP temp = -118.9
Altitude ~ 140,000 km

OBSID = 62956

Start			GMT 214:02:38
1st bias packet		GMT 214:02:49
Last bias packet	GMT 214:02:59
switch to FMT 1		GMT 214:03:02
1st data packet		GMT 214:04:31
Stop Science		GMT 214:04:49

Run	# of frames
1	1649
2	349


** the last run squeezed out 349 frames because the OC/CC were working
at maximum efficiency, they uplinked the loads for the Internal Cal
Source Measurement BEFORE they sent the stop science. Very nice.


2. Internal Cal Source Measurement for the fourth time.
Please somebody help me, I am living the movie Groundhog Day !!!!!

   - Timed Exposure Faint Mode on the I array, no g7 events
FP temp = -118.7 C
Altitude ~ 140,000 km

OBSID == 62735
Start science at GMT 214:04:58
Stop Science at  GMT 214:07:40

Michael Pivovaroff, the eminent project graduate student, noted that there were
~490,000 events on S3 and ~110,000 events on S2 in this first science
run in a total of 2500 frames.

** Note, we had severe TLM dropouts during the Dumps. We received
every command echo in the ltlm window but PMON did not report two of
the dumps, dumpBadPixels and dumpDumpHuffman

   - Timed Exposure Faint Mode on the S array, no g7 events
FP temp = -118.7 C
Altitude ~139,000 km

   OBSID 62734
   Start Science at GMT 214:07:44
   Stop Science  at GMT 214:10:25

Michael Pivovaroff, the eminent project graduate student, noted that there were
~490,000 events on S3 and ~110,000 events on S2 in this first science
run in a total of 2475 frames.

   - Timed Exposure Faint Mode on the S array, no b255 events, only
telemeter events from S2 and S3
FP temp = -118.7 C
Altitude 133,000 km

   OBSID 62733
   Start Science at GMT 214:10:29
   Stop Science  at GMT 214:13:00 --> planned stop


Staff: 

ACIS: Royce Buehler, Paul Plucinsky, Ellen Sen, Shanil Virani, Michael
Pivovaroff
SOT: LEAD: Dan Schwartz
ACA: Rob Cameron
EPHIN/PCAD: Eric Martin