1. GLAST Large Area Telescope:
Gamma-ray Large Area Space Telescope
GLAST Large Area Telescope:
Design Integration Overview
Lowell A. Klaisner
Stanford Linear Accelerator Center
LAT Chief Engineer

2. Design Integration Talks
This Talk
Second Talk
Third Talk
First Talk
Thursday 1:30 PM

3. LAT Documentation Status
Subsystem Drawings

4. Parts Qualification Materials and processes – Jeff Tice
Electrical Electronic and Electromechanical – Nick Virmani
See talk Thursday at 2:00 pm

5. Peer Reviews Peer reviews held for all subsystems
Reviewers were experts in the relevant technical areas from GSFC, the aerospace industry, and science community
General concurrence with the current design
Identified technical issues that are being addressed by the subsystem engineers
This process of reviews is important to assuring a quality design and, therefore, the success of the mission

6. Trades Associated With Interface Finalization
Internal Interfaces
External Interfaces

7. Open Design Issues X-LAT Plate Design
A recent design trade transferred the structural load of the electronic boxes from the X-LAT plate to the calorimeter plates.
This results in a single function for the X-LAT plate -- providing a thermal path from the electronics boxes to the radiators and a thermal path between the radiators.
Details of the flexible (in X&Y) thermal connection between the plate and the electronics boxes are being worked.
Calorimeter to GRID joint
The baseline design of a friction joint carrying shear forces was deemed inadequate. Alternate designs are being pursued.
Application Specific Integrated Circuit (ASIC) Design
Not all of the designs are proven

8. Design Maturity All subsystems have been through peer reviews
Details in each subsystem presentation
ACD
Design is mature and tested
Open issues on the ASICs and FREE board
Model testing well along – electronics module environmental testing planned
Mounting flexure design needs testing
Tracker
Design complete with adequate margins
Open issues around the manufacturing details of the MCMs
Engineering model is in test – positive first results

9. Design Maturity (2) Mechanical GRID and radiator design mature
Overall thermal control system well characterized
X-LAT design at early stage of design
1X4 Engineering model in fabrication
Data Acquisition System
“The electronics design is sufficiently mature with many improvements and optimizations that were prudent” – peer review summary
Detail designs in progress
Spacecraft interface
Working groups are resolving technical issues
Spacecraft PDR last week

10. Design Integration
Thermal, Structural and Electronic interfaces are defined
LAT Thermal and Structural models are complete
Analysis underway
Open integration issues
Thermal system design closure
Structural issue closure
CAL - GRID interface
Electronics – X-LAT plate interface