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Lunar Regolith Protection System
Dalhousie UniversityMechanical Engineering
MECH 4010Team #3
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
LunarRegolithProtection System
Team #3Dec 1 2008Slide #3
Problem DefinitionBackgroundRequirementsAlternative DesignsFinal DesignPreliminary TestingCurrent StatusConclusionsAcknowledgements
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 oC)– Micro-meteorites– High radiation
LunarRegolithProtection System
Team #3Dec 1 2008Slide #2
Problem DefinitionBackgroundRequirementsAlternative DesignsFinal DesignPreliminary TestingCurrent StatusConclusionsAcknowledgements
Background• Regolith– Highly abrasive– Irregular shape– Abundant in lunar environment– Small particle size– Electrodynamic properties
LunarRegolithProtection System
Team #3Dec 1 2008Slide #2
Problem DefinitionBackgroundRequirementsAlternative DesignsFinal DesignPreliminary TestingCurrent StatusConclusionsAcknowledgements
Source: JPL/NASA
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
LunarRegolithProtection System
Team #3Dec 1 2008Slide #4
BackgroundProblem DefinitionRequirementsAlternative DesignsFinal DesignPreliminary TestingCurrent StatusConclusionsAcknowledgements
SMA Actuated Flexible Lid
• Roll-back lid actuated by SMA strips embedded in flexible material
• Complicated control circuitry required
LunarRegolithProtection System
Team #3Dec 1 2008Slide #5
Problem DefinitionBackgroundRequirementsAlternative DesignsFinal DesignPreliminary TestingCurrent StatusConclusionsAcknowledgements
Control circuitry for thin film heaters
Rolls back
Modification of Original Lid
• Modify geometry to control the position and flow of dust particles
• Bulky design• Risks associated with motor hinge
LunarRegolithProtection System
Team #3Dec 1 2008Slide #6
Problem DefinitionBackgroundRequirementsAlternative DesignsFinal DesignPreliminary TestingCurrent StatusConclusionsAcknowledgements
Motor and hinge
Magnetic Vacuum• Solenoid / Permanent magnet– Excessive loads on moving
components–Magnetic properties of regolith
are not validated
LunarRegolithProtection System
Team #3Dec 1 2008Slide #7
Problem DefinitionBackgroundRequirementsAlternative DesignsFinal DesignPreliminary TestingCurrent StatusConclusionsAcknowledgements
Final DesignLunarRegolithProtection System
Team #3Dec 1 2008Slide #11
Problem DefinitionBackgroundRequirementsAlternative DesignsFinal DesignPreliminary TestingCurrent StatusConclusionsAcknowledgements
Passive Protection• Lid profile• Overlapping mating surface
LunarRegolithProtection System
Team #3Dec 1 2008Slide #8
Problem DefinitionBackgroundRequirementsAlternative DesignsFinal DesignPreliminary TestingCurrent StatusConclusionsAcknowledgements
SMA Hinge• Each hinge comprised of 3
Nitinol (55% - Ti 45% - Ni) strips (2 for closing, 1 for opening)
• Activated by thin-film heaters
LunarRegolithProtection System
Team #3Dec 1 2008Slide #9
Problem DefinitionBackgroundRequirementsAlternative DesignsFinal DesignPreliminary TestingCurrent StatusConclusionsAcknowledgements
Active Protection• Capacitor– “Collar” located in base around
receiver– “Electric curtain”– Vacuum acts as near perfect insulator
LunarRegolithProtection System
Team #3Dec 1 2008Slide #10
Problem DefinitionBackgroundRequirementsAlternative DesignsFinal DesignPreliminary TestingCurrent StatusConclusionsAcknowledgements
Preliminary Testing• Rapid prototyped lid and base
design• SMA wire hinge• COMSOL models of capacitor
design
LunarRegolithProtection System
Team #3Dec 1 2008Slide #12
Problem DefinitionBackgroundRequirementsAlternative DesignsFinal DesignPreliminary TestingCurrent StatusConclusionsAcknowledgements
Current Status• Awaiting SMA strips• Improving machinability of lid
design• Developing testing plan– Lid profiles–Mating surfaces– SMA hinges– Capacitor
LunarRegolithProtection System
Team #3Dec 1 2008Slide #13
Problem DefinitionBackgroundRequirementsAlternative DesignsFinal DesignPreliminary TestingCurrent StatusConclusionsAcknowledgements
Conclusions• Complexity of lunar
environment• Multi-layered solutions are
critical for dust protection• Design strengths– SMA hinge – Lid geometry– Active protection– Operational protocol
LunarRegolithProtection System
Team #3Dec 1 2008Slide #14
Problem DefinitionBackgroundRequirementsAlternative DesignsFinal DesignPreliminary TestingCurrent StatusConclusionsAcknowledgements
Acknowledgements• Dr. Marie-Josée Potvin• Dr. Andrew Warkentin• Dalhousie University
Mechanical Engineering Department
• Shell Canada
LunarRegolithProtection System
Team #3Dec 1 2008Slide #15
Problem DefinitionBackgroundRequirementsAlternative DesignsFinal DesignPreliminary TestingCurrent StatusConclusionsAcknowledgements
Questions?LunarRegolithProtection System
Team #3Dec 1 2008Slide #16
Problem DefinitionBackgroundRequirementsAlternative DesignsFinal DesignPreliminary TestingCurrent StatusConclusionsAcknowledgements