1. Spacecraft Interface and I&T
EFI Instrument
Spacecraft Interface and I&T
Preliminary Design Review
Bill Donakowski
Mechanical Engineer
University of California - Berkeley

2. Radial Booms (4X) Located Orthogonal to each other
Spacecraft Interface
Radial Booms (4X) Located Orthogonal to each other
X-Y Plane
Spin Companions (A/B & C/D)
In-Line +/- 1 degree
Opposing Units
Perpendicular +/- 2 degrees
Z Axis
Boom Deploy Centerline w/i 2mm for all units on Probe
Boom Deploy Centerlines w/i TBD to Probe CG
Axial Booms (2X)
Both Booms Built-Up Together at UCB
Boom Assy Fits into Probe Opening
Goal of Line-Of-Sight Access for Bolts Instl and Inspection as Possible

3. Interface to Probe Issues
Axial Booms
Careful Coordination required as Boom Tube is Primary Structure to Probe
Installation and Removal Design and procedures in-work
Probe Antenna part of Boom
Testing of Antenna may be issue
Installation of units need to be coordinated
Radial Booms
Probe Propellant Tanks/SPBs in close proximity
Issue being worked by UCB/Swales Designers
Shadowing of SPB Doors and Exit Tube on Solar Array TBD
Deployed Spin Plane Booms and relationship to Probe Thruster Plume TBD
Both Thrusters and Axial Boom Spin Plane in-line
Thermal effects of plume on Wire TBD (not preferred)

4. EFI Instrument on Probe
Axial Boom
4 x SPB
Probe Mounting Deck

5. SPB on Spacecraft Probe Tank Plane of Exterior Solar Panel (Removed)
SPB Release Doors
Probe Deck
Close Proximity to Tank
(~.45”)

6. Axial Boom On S/C AXIAL BOOM INTEGRATION TO THEMIS PROBE
Antennae Mount
Axial Boom
Composite Tube
Upper Deck Mount
Lower Deck Mount
THEMIS PROBE WITH AXIAL BOOM
AXIAL BOOM

7. Integration and Test Philosophy
Environmental Test Instrument Subassys Individually
Build up EFI Instrument on S/C Simulator
Test/Check-Out/Compatibility
Populate Qualified and Checked out Instruments onto Probe
Perform minor electrical/continuity checks following Probe Integration
Enable Plugs with connection break-outs at Subassys
Safety as well as good check of End-to-End
Rationale
Various Components tested together to Best Select based on compatibility
Untie Probe/Instrument Schedules as much as possible
Limit Probe/Instrument Integration times
Limit need to change out Instruments due to Problems

8. Pre-Integration Testing
Overall Check-Out
EFI Instrument completely Checked-Out Prior to arrival of Probe
Continuity Check at Enable Plug Break-Out
Able to send signal from IDPU to Break-Out Boxes
Command Deploy
Monitor Virtual Motor
Verify Integrity of Sphere Surface

9. Post-Integration Testing
Overall Check-Out
Perform minor electrical/continuity checks following Probe Integration
Send Signal to Enable Break-Out Boxes
Verify Signal Send/Receive
No Functional Checks of Full-Up Instrument Following Integration
Deployment Motors not Powered
No Operation of Doors
No Operation of Pin Pullers

10. Integration to Probe Issues
Axial Booms
Access may be a problem
Probe Antenna part of Boom
Safety concern of Deployment on ground
Radial Booms
Maintenance and check-out of Sphere Surface late in the flow as possible