To:sot_shift
from: Dan Schwartz
date: 18 May 00 , 12:00noon EDT
Subject: SOT shift report, Shift L300
--------
See http://asc.harvard.edu/acis/SOT_reports/sot-shift.html, or 
/proj/ascwww/AXAF/extra/science/htdocs/acis/SOT_reports/May_18_2000_L300.txt.

Shift L300. 
	Start at 139:12:00  GMT
		 = 08:00am    18 May EDT
	End	   12:00 noon 18 May
   
SOT Lead	DAS

(Times will be given in GMT on day 139. In general
times are rough, not precise.)

PLAN
Continue running load MAY1600c (the rebuild with wider star magnitude
selection windows). Finish the DDT/TOO coordinated observation of EX
Hya, OBSID 1706, with ACIS-S/HETG. Following that will be OBSID 852,
ACIS-S observation of the BAL quasar 1312+2319; OBSID 543, ACIS-I
observation of the cluster MS 1455.0+2232; and OBSID 803, ACIS-S
observation of the ram-pressure stripped galaxy M84 in the Virgo
cluster.

Next Comms: 
 139:15:20 to 16:20
 139:23:00 to 00:00
 140:08:30 to 09:30
 141:05:00 to 06:00
 141:13:55 to 14:55
 141:22:00 to 23:00
 142:07:00 to 08:00
 142:14:30 to 15:30
 143:00:30 to 01:30

EVENTS
15:22  AOS
	The HETG is inserted, as it should be!! (First post-anomaly
use of HETG.)


Status at AOS, 139:15:23, was as follows:
       PCAD MODE              =       NPNT
       CONTROL LAW FLAG       =       NPNT
       Stars:                 =          5 
       FIDS                   =          3
       RA                     =    193.080 deg 
       DEC                    =    -29.233 deg
       ROLL                   =    274.184 deg
       Format                 =          2
       OBSID                  =       1706 (EX Hya)

       SIM FA                 =       -467
       SIM TSC                =      74424 (ACIS-S)
       HETG                   =         IN ( 6.3 deg)
       LETG                   =        OUT (78.7 deg)
        HRC-S HV is ON 
        EPHIN:         A-Leak =  0.2360 mu-a
                       B-Leak =  0.0400 mu-a

16:19 LOS
	Status essentially unchanged from AOS.

	ACIS focal plane temperature was -119.7 throughout the contact.


NOTES/ISSUES/PROBLEMS
Chandra snapshot has stopped as of 138:14:53. We have no status at
last LOS. Has been restarted successfully for the 139:15:20 pass.

The TOO target XTE J1550-564 was at 0.14 Crab yesterday, based on 5
RXTE observations.

From 9am status meeting:
	Products for MAY2100 went out last night, first load review
planned for 1pm today. 
	Meeting expected for 9:30am tomorrow to discuss general star
selection issues, including recent non-acquisition of stars with
narrower magnitude limit ranges. To be scheduled by Dan Shropshire.
	FOT/TRWwest team is starting look ahead planning for the partial lunar
eclipse expected next Oct 28. This will be difficult because the solar
panels will cool and become very efficient, potentially resulting in
an overvoltage on the bus. There will be a telecon at noon today --
Wallace Jackson expects to recommend off pointing the solar arrays to
be edge on to the sun, and then riding out this ~42 min. eclipse as any
other medium length total eclipse.

From the 10am ACIS ops meeting.
	Squeegy mode operations can trade off many parameters,
e.g. number of rows, slowing parallel transfer, dwelling, on-chip
summation, sub-arrays, -- More cases and permutations than we would
want to test on-orbit. The MIT team has defined 4 specific cases to
test:
1) Do everything possible to maximize spectral resolution. 2) Do
everything EXCEPT sacrificing spatial resolution, i.e., no on chip
summing. In 2a) we'll do a 256 row subarray (which produces the same
time delay as 2 x 2 pixel summing) and in 2b) we'll do the full 1024
row chip. 3) Do everything possible consistent with a minimum 
dead time -- e.g., no extra dwell times between frames. 
The detailed parameters to be used in each test are defined from the
on-going laboratory efforts.
	The concept is to first do these as real time tests on S0, to
prove that each specific patch functions as expected and get a
performance assessment on the most degraded flight chip. We hope to do
these every 4 perigee passages, about 10 days, during quasi-normal
hours. Then each test would be repeated on I0, to test the exact
performance on the I-array which will be the actual chips used on
science targets, and later on S1, to assess the effect on a back side
chip. These repeat tests will be done via Stored Command Loads, to
minimize operational impacts, and can be scheduled for any of the perigee
passages not being used for real-time commanding. We hope to start in
the MAY2800 load.
	We must anticipate possible changes based on possible
surprises from the on-orbit testing compared with expectations from
lab testing. 
 
-------------------------------------------------------
Dan Schwartz,	MS #3
das@head-cfa.harvard.edu  
phone: (617)495-7232    FAX:   (617)495-7356
cell phone: (617)512-5627   
pager: 800-759-8352 PIN 1636502
       or e-mail 1636502@skytel.com 
-------------------------------------------------------