Date: Sat, 24 Aug 2013 16:53:51 -0400
Subject: SOT shift report 2013-08-24 (MUPS Swap)
From: "Juda, Michael" <mjuda@cfa.harvard.edu>

During the 2013:236:1900-2100 comm pass CAPs 1290 and 1291 were executed to swap from using MUPS-A to using MUPS-B for routine operations. 
- Valve-drive Electronics (VDE)-B was powered on
- Auto-unloading was disabled
- Stored-command sequences used for hardware configuration, selection in safing actions, and the momentum dump cutoff were patched on both OBCs to reflect the change in roles
- VDE-B was selected for use
- A momentum dump to a planned target momentum was performed via the OBC
- VDE-A was powered off

The momentum dump was planned such that the B2 thruster would not be used. Thrusters B1, B3, and B4 all performed at nominal thrust output.

Chandra is now configured to use MUPS-B for routine
operations and MUPS-A for safe-mode.


Momentum dumps are being planned to avoid the use of thruster B2 and scheduled to occur during comm passes so that the MUPS thruster performance can be monitored in real-time.