1. Post Deployment Analysis
MAGIC Tether
Post Deployment Analysis

2. Deployed Tether Geometry
Tip Mass (5kg)
Velocity
20m
Libration Angle
Nadir
Zenith
Oscillating Frequencies:
Roll Oscillating Frequency = Hz
Pitch Oscillating Frequency = Hz
Yaw Oscillating Frequency = Hz
Main Structure (25kg)

3. Current Issues Tension and Libration
Pendulum Motion Requires Accurate Deployment
Tether Tape Material Properties

4. Tension Analysis
For a 20m tether, Tension will be approximately 0.3mN.
Tension this low could fail to provide adequate control in the pitch and roll axes of DINO.
At low tension, tip mass and main structure would rotate freely until tension builds up.

5. Pendulum Motion
Pendulum motion of DINO in the pitch and roll axes might not damp out over time.
Accuracy of the deployment would define the pointing accuracy of DINO.
±10º off of nadir would be possible.

6. Material Properties Thermal Expansion (20x10-6mm/mm/K)
13.7cm expansion in sun
Thermal Snap-Contraction (100x10-6/mm/mm/K)
68.6cm contraction in shade
Stress vs. Strain of Tether
Effective Modulus could differ from specs.

7. Conclusion Issues/Risks Recommendation Lack of Tension
Pendulum Motion will not damp out
Tether expands and contracts in and out of sunlight
Recommendation
A boom would be more rigid and could provide more predictable control.
Build a emergency release mechanism for the tether if it is used and provide a backup such as a reaction wheel.

8. Appendix

9. Appendix cont’d

10. Appendix cont’d