GLAST Proposal Review

1
GLAST Large Area Telescope Design Integration
Overview Lowell A. Klaisner Stanford Linear
Accelerator Center LAT Chief Engineer klaisner_at_sl
ac.stanford.edu
2
Design Integration Talks
This Talk
Second Talk
First Talk
Third Talk
Thursday 130 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 200 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 XY) 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