To: sot_shift
Subject: SOT shift report: pre-launch B-shift
Date: Mon, 19 Jul 1999 23:09:14 -0400
From: Tom Aldcroft <aldcroft@head-cfa.harvard.edu>

During the pre-launch B-shift, everything went smoothly and
at this time all systems are go.  We are still on track
for launch at 12:53 am. 

A key issue is that the ACIS pressure is higher than expected, and will be
above 4.6, but less than 10.  This means that an on-time little-vent-valve
opening is crucial.  At this time the nominal timeline will be followed,
but everyone is aware of the ACIS situation.

For some time there was concern about the shuttle CIU, which
allows the crew to manually send command to the IUS.  This
concern turned out to be a non-issue.  No other significant
anomalies arose.  Below is a log of events:

** Day 1999:200 **  (times GMT)

15:40 - ACIS Pressure expected to be over 4.6, less than 10.0.  Nominal
 timeline will be followed

15:59 - Steps 1-10 in nominal procedure are complete

18:01 - There is an issue with the CIU.  This impacts
 crew's ability to control IUS via on-board thumbwheels, which is needed
 for certain commands.  It may be possible to re-direct commanding
 through PI.  This would result in less than nominal command time 
 available for Chandra commanding - possible impact to time before
 ACIS LVV opening.

18:28 - Current suspicion is that CIU may be OK, but interpretation
 of "nominal" response to test sequence is uncertain.  Perhaps config
 failures.  

20:28 - Steps 12, 13, 14 complete.  Step 11 open, Sunnyvale loops have 
 problem. 

21:01 - Step 15 complete

~22:00 - CIU problem is declared a non-issue.

22:53 - All voice loop and interface/command checks req'd to this point
 are complete.  KSC and OAS command checks still to be done.
 Complete through step 16.

** Day 1999:201 **

01:40 - All com checks done so far are good

02:36 - Comm checks with Sunnyvale and Diego/Garcia reported successful