1. GLAST LAT System Engineering
Gamma-ray Large Area Space Telescope
GLAST LAT System Engineering
LAT Test Configurations
Rich Baun
SLAC
(650)

2. Why Test Configurations?
LAT Level testing must, among other things, verify:
The correct function of all LAT primary and redundant units
The correct function of all interfaces between LAT primary units, LAT redundant units,and the Spacecraft
The correct function of all copper paths within the LAT and from the LAT to the Spacecraft
Provide at least 250 hours (TBD) of on time for each LAT unit
Establishing Test Configurations accomplishes the verification of unit functions and their interfaces
Configurations selected so that each unit and it’s prime, redundant, and cross-strapped interfaces are verified
Sufficient testing performed in each configuration to verify the proper function of each unit
Performance testing is done mainly in the all prime configuration
Cross-strapped configurations have significantly fewer test procedures executed as only interfaces/copper paths are verified
Test configurations minimize unit power cycles and provide test repeatability and configuration control
LAT Level testing will require 6 separate configurations to verify all unit functions and interfaces (see next slide)

3. Proposed LAT Test Configurations

4. LAT Configurations vs. Interfaces Verified
Notes:
SC-P indicates all primary SC-LAT electrical signals, excluding power feeds
SC-R indicates all redundant SC-LAT electrical signals, excluding power feeds