lunar regolith protection system dalhousie university mechanical engineering mech 4020 team #3

Lunar Regolith Protection System

Dalhousie UniversityMechanical Engineering

MECH 4020Team #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 #3Apr 8 2009Slide #2

Problem DefinitionFall ‘08 DesignFinal DesignAdjustable BracketsLid and BaseActive Protection

SystemSMA HingeComplete DesignPerformanceLimitationsBudgetRequirementsConclusions

Fall Semester DesignLunarRegolithProtection System

Team #3Apr 8 2009 Slide #3



• Final conceptual design as of December ‘08

Final DesignLunarRegolithProtection System




• Improvements made to December ‘08 design

Adjustable BracketsLunarRegolithProtection System




• Allow for fine-tuning of SMA orientation before the range of motion becomes consistent

• Final dimensions of SMA’s would be used

• Fasteners eliminated from actual model

LidLunarRegolithProtection System




• Lid profiles unchanged• Additional lip on minor lid to prevent dust

from infiltrating seam

BaseLunarRegolithProtection System




• Male mating surface along rim for accurate seating of lids

• SMA attachment moved to base plate

Active Protection System





• Charged particles are attracted to the capacitor plates and will not interfere with LIDAR operation

• Testing demonstrated that 100% of charged particles are collected

Testing: Active Protection System





• Capacitor mock-up in Styrofoam block

• Arcing caused by plates being too close

• Nitinol (NiTi) actuator alloy

• Transformation Temperature: 40oC

SMA HingeLunarRegolithProtection System




SMA HingeLunarRegolithProtection System




Thin-film Heaters Final Dies

Testing:SMA Hinge





SMA Wire Small SMA Strips

Testing:SMA Bowing





Passive Strip

Active Strips

Clamping Bars

Complete SystemLunarRegolithProtection System




System PerformanceLunarRegolithProtection System




Parameter

Active System Power Requirement 0.5 W-SS 1.0 W-Peak

SMA Hinge Power Requirement 20 W

Consistent Range of Motion 75 degrees

Opening Time Approx. 20 s

Closing Time Approx. 20 s

Minimum Cycle Time 10 min

SMA Transition Temperature Approx. 40 deg C

Max. Operational SMA Temperature (8.5W/in2) 80 deg C

Particle Infiltration Trace

System PerformanceLunarRegolithProtection System




0 10 20 30 40 50 60 70 800

20

40

60

80

100

120

Actuator Temp vs Time

5.8 W/in^28.5 W/in^210 W/in^2

Time since Activation (s)

Actu

ator

Tem

pera

ture

(C)

• Power requirements• Lid mating and range of motion

LimitationsLunarRegolithProtection System




0 5 10 15 20 25 300

20

40

60

80

100

120Lid Range of Motion vs Cycle

Cycle Number

Rang

e of

Moti

on (d

egre

es)

BudgetLunarRegolithProtection System




Expense CostSMA Strips $280

Thin-film Heaters $640

Power Supply $80

Teflon $120

Rapid Prototyping $290

Miscellaneous (hardware, wiring, etc.) $30

TOTAL EXPENSES $1440

BUDGET $1450

RequirementsLunarRegolithProtection System




Constraints Met?Withstand extreme thermal conditions

Withstand high radiation environment

Must not rely on gravity

No unvented cavities

Must not interfere with LIDAR operation

RequirementsLunarRegolithProtection System




Criteria Met?Minimize power requirements

Minimize weight and size

Last at least 3 months in lunar environment

Minimal regolith accumulation on instrument

Conclusions• Complexity of lunar

environment• Multi-layered solutions are

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





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

Mechanical Engineering Department

• Shell Canada





Questions?LunarRegolithProtection System




lunar regolith protection system dalhousie university mechanical engineering mech 4020 team #3

Documents

design slide

phoenix design design

final design team

problem definition design

fall semester design

active protection system

complete system team

system performance team