lunar regolith protection system dalhousie university mechanical engineering mech 4010 team #3

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




Background• Regolith– Highly abrasive– Irregular shape– Abundant in lunar environment– Small particle size– Electrodynamic properties




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



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




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




Motor and hinge

Magnetic Vacuum• Solenoid / Permanent magnet– Excessive loads on moving

components–Magnetic properties of regolith

are not validated




Final DesignLunarRegolithProtection System



Passive Protection• Lid profile• Overlapping mating surface




SMA Hinge• Each hinge comprised of 3

Nitinol (55% - Ti 45% - Ni) strips (2 for closing, 1 for opening)

• Activated by thin-film heaters




Active Protection• Capacitor– “Collar” located in base around

receiver– “Electric curtain”– Vacuum acts as near perfect insulator




Preliminary Testing• Rapid prototyped lid and base

design• SMA wire hinge• COMSOL models of capacitor

design




Current Status• Awaiting SMA strips• Improving machinability of lid

design• Developing testing plan– Lid profiles–Mating surfaces– SMA hinges– Capacitor




Conclusions• Complexity of lunar

environment• Multi-layered solutions are

critical for dust protection• Design strengths– SMA hinge – Lid geometry– Active protection– Operational protocol




Acknowledgements• Dr. Marie-Josée Potvin• Dr. Andrew Warkentin• Dalhousie University

Mechanical Engineering Department

• Shell Canada




Questions?LunarRegolithProtection System



lunar regolith protection system dalhousie university mechanical engineering mech 4010 team #3

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