1. Lunar Regolith Protection System Dalhousie University Mechanical Engineering MECH 4010 Team #3

2. Problem Definition Design an apparatus or system to protect Light Detection and Ranging System (LIDAR) instrument from regolith Improve upon Phoenix design Design must function in a lunar environment Team #3 Dec 1 2008 Slide #3 Problem Definition Background Requirements Alternative Designs Final Design Preliminary Testing Current Status Conclusions Acknowledgements

3. Background LIDAR –Comprised of laser and receiver –Measures atmospheric and geomatic properties Lunar Environment –28-day lunar rotational period –1/6 gravity of earth –No atmosphere –Extreme temperatures (max range: -220 – 120 o C) –Micro-meteorites –High radiation Team #3 Dec 1 2008 Slide #2 Problem Definition Background Requirements Alternative Designs Final Design Preliminary Testing Current Status Conclusions Acknowledgements Problem Definition Background Requirements Alternative Designs Final Design Preliminary Testing Current Status Conclusions Acknowledgements

4. Background Regolith –Highly abrasive –Irregular shape –Abundant in lunar environment –Small particle size –Electrodynamic properties Team #3 Dec 1 2008 Slide #2 Problem Definition Background Requirements Alternative Designs Final Design Preliminary Testing Current Status Conclusions Acknowledgements Source: JPL/NASA

5. Requirements Constraints –Withstand extreme thermal conditions –Withstand high radiation environment –Must not rely on gravity –No unvented cavities –Must not interfere with LIDAR operation Criteria –Minimize power requirements –Minimize weight and size –Last at least 3 months in lunar environment –Minimal regolith accumulation on instrument Team #3 Dec 1 2008 Slide #4 Background Problem Definition Requirements Alternative Designs Final Design Preliminary Testing Current Status Conclusions Acknowledgements

6. SMA Actuated Flexible Lid Roll-back lid actuated by SMA strips embedded in flexible material Complicated control circuitry required Team #3 Dec 1 2008 Slide #5 Problem Definition Background Requirements Alternative Designs Final Design Preliminary Testing Current Status Conclusions Acknowledgements Control circuitry for thin film heaters Rolls back

7. Modification of Original Lid Modify geometry to control the position and flow of dust particles Bulky design Risks associated with motor hinge Team #3 Dec 1 2008 Slide #6 Problem Definition Background Requirements Alternative Designs Final Design Preliminary Testing Current Status Conclusions Acknowledgements Motor and hinge

8. Magnetic Vacuum Solenoid / Permanent magnet –Excessive loads on moving components –Magnetic properties of regolith are not validated Team #3 Dec 1 2008 Slide #7 Problem Definition Background Requirements Alternative Designs Final Design Preliminary Testing Current Status Conclusions Acknowledgements

9. Final Design Team #3 Dec 1 2008 Slide #11 Problem Definition Background Requirements Alternative Designs Final Design Preliminary Testing Current Status Conclusions Acknowledgements

10. Passive Protection Lid profile Overlapping mating surface Team #3 Dec 1 2008 Slide #8 Problem Definition Background Requirements Alternative Designs Final Design Preliminary Testing Current Status Conclusions Acknowledgements

11. SMA Hinge Each hinge comprised of 3 Nitinol (55% - Ti 45% - Ni) strips (2 for closing, 1 for opening) Activated by thin-film heaters Team #3 Dec 1 2008 Slide #9 Problem Definition Background Requirements Alternative Designs Final Design Preliminary Testing Current Status Conclusions Acknowledgements

12. Active Protection Capacitor –“Collar” located in base around receiver –“Electric curtain” –Vacuum acts as near perfect insulator Team #3 Dec 1 2008 Slide #10 Problem Definition Background Requirements Alternative Designs Final Design Preliminary Testing Current Status Conclusions Acknowledgements

13. Preliminary Testing Rapid prototyped lid and base design SMA wire hinge COMSOL models of capacitor design Team #3 Dec 1 2008 Slide #12 Problem Definition Background Requirements Alternative Designs Final Design Preliminary Testing Current Status Conclusions Acknowledgements

14. Current Status Awaiting SMA strips Improving machinability of lid design Developing testing plan –Lid profiles –Mating surfaces –SMA hinges –Capacitor Team #3 Dec 1 2008 Slide #13 Problem Definition Background Requirements Alternative Designs Final Design Preliminary Testing Current Status Conclusions Acknowledgements

15. Conclusions Complexity of lunar environment Multi-layered solutions are critical for dust protection Design strengths –SMA hinge –Lid geometry –Active protection –Operational protocol Team #3 Dec 1 2008 Slide #14 Problem Definition Background Requirements Alternative Designs Final Design Preliminary Testing Current Status Conclusions Acknowledgements

16. Acknowledgements Dr. Marie-Josée Potvin Dr. Andrew Warkentin Dalhousie University Mechanical Engineering Department Shell Canada Team #3 Dec 1 2008 Slide #15 Problem Definition Background Requirements Alternative Designs Final Design Preliminary Testing Current Status Conclusions Acknowledgements

17. Questions? Team #3 Dec 1 2008 Slide #16 Problem Definition Background Requirements Alternative Designs Final Design Preliminary Testing Current Status Conclusions Acknowledgements