1. Space Frame Telescope Structures for SNAP: Part II
Bruce C. Bigelow
University of Michigan
Department of Physics
8/26/04

2. Space Frames for SNAP Status:
Determinate structures for TMA-63 presented 7/28/04
Two new structure concepts under development
Both are indeterminate
Both use TMA-65 optics
Shutters, star trackers, tertiary support added to models
Conceptual design of nodes (joints) underway

3. Indeterminate structure PR-10
Features:
Indeterminate design (over-constrained)
Instrument section non-symmetric WRT OTA
Instrument section has 3-fold symmetry between tertiary and focal plane
Lots of room for star-trackers, etc.
Fewer nodes and struts than PR-11

4. Pr-truss10

5. Pr-truss10

6. Pr-truss10

7. Indeterminate structure PR-11
Features:
Main sections have 3-fold symmetry
Instrument section has 3-fold symmetry for tertiary and focal plane
More nodes and struts than PR-10
More complicated nodes than PR-10
Lots of room for star-trackers, etc.

8. Pr-truss11

9. Pr-truss11

10. Pr-truss11

11. Indeterminate structures
Conclusions:
Indeterminate structures for TMA-65 demonstrated
Most of cost, time, effort will go into node design
Recent input from LBL composites expert Eric Anderssen
Get more input from manufacturers
Work on nodes next!