Methods of Dust Mitigation with Applications to Lunar and Martian Missions

1
Methods of Dust Mitigation with Applications to
Lunar and Martian Missions
Jordan Wirfs-Brock Mentor Dr. Juan Agui,
Microgravity Division
2
Motivation

• Why do we care about dust?
• Mechanical problems
• Electrostatic problems
• Health problems
• What is special about Lunar dust?
• What is special about Martian dust?
• Can dust be useful?

3
Project 1 Abrasion Testing of an Electrostatic
Coating

• Why an electrostatic coating?

• What exactly are we trying to test?
• - How does this relate to the applications?
• Experimental questions/issues
• - What conditions are we trying to simulate?
• - Duration of corrosion

4
Project 1 Abrasion Testing of an Electrostatic
Coating

• Main Components
• Translating Stage
• Displacement Sensor
• Flat leaf spring

5
Project 1 Abrasion Testing of an Electrostatic
Coating

• Initial Design

6
Project 1 Abrasion Testing of an Electrostatic
Coating

• Final Design

7
Project 1 Abrasion Testing of an Electrostatic
Coating
Displacement sensor
Displacement sensor

• Deflection of the spring gt relative motion
  between the test-slide and the translating
  stage/sensor
• Relative motion gt force balance gt frictional
  force felt by the slide

8
Project 1 Abrasion Testing of an Electrostatic
Coating
Displacement sensor calibration, 0.001 thick
target
Displacement (m)
10th order best-fit curve
f(x) 0.0032115x10 0.0062041x9 0.0029192x8
0.0014434x7 0.0040341x6 0.0048883x5
0.0046574x4 0.003932x3 0.0030839x2
0.0023046x 0.0016687
Sensor Voltage (V)
9
Project 1 Abrasion Testing of an Electrostatic
Coating

• Translating stage calibration
• Procedure Dial indicator
• Results Inconsistent step size
• Problems Dial indicator problems, resolution of
  measurements
• Flat leaf spring calibration
• Procedure Loading with known masses
• Results Inconsistent spring constants
• Problems Deflections too small to be measured
  accurately

10
Project 1 Abrasion Testing of an Electrostatic
Coating
Control Data (no sample)
Output voltage (V)
Pre-motion
Motion
Post-motion
Un-coated glass sample
Coefficient of static friction
Coefficient of dynamic friction
Time (s)
11
Project 1 Abrasion Testing of an Electrostatic
Coating

• Did the experimental set-up work? Yes and no
• Functions mechanically (springs yield
  displacements within measurable range)
• Back-calculated friction coefficients for glass
  on glass do not match known values
• Possible explanations spring not linear,
  calibration errors

Flat leaf spring
Displacement sensor
Translating stage
Coated slide
Glass base
12
Project 1 Abrasion Testing of an Electrostatic
Coating
Continuation of abrasion testing
13
Project 2 Modeling Dust Dynamics

• Physical problem/model
• Extracting oxygen from lunar dust by shaking and
  heating
• How can we model that simply?
• Software capabilities
• PFC3D
• What happens when you put the two together?
• Is this software able to demonstrate states
  observed in real life?
• Is this software a useful tool for analyzing this
  heating method?

14
Simulation views and geometry -Cylinder with 5
cm diameter -Hard spheres with 3 mm
diameters -Between 700 and 6000 particles
15
Project 2 Modeling Dust Dynamics

• Observations and concerns
• Long computing time (20 hours for 1/6 of a
  second)
• What are the starting conditions?
• Will convection occur?
• Are material properties of glass beads
  appropriate? How to model lunar regolith?
• Amplitude of oscillations
• Problems with the software
• Unexplainable compaction
• Abnormal/unrealistic physical behavior

16
Project 2 Modeling Dust Dynamics
Physically unrealistic behavior, side view
17
Project 2 Modeling Dust Dynamics
Physically unrealistic behavior, top view
18
Project 2 Modeling Dust Dynamics
Is PFC3D software useful to this application?
Heres my take
19
Where do we go from here?

• Continuation of projects mentioned
• Future projects
• Vacuum chamber for dust impact dynamics
• Dust flow in vacuum

20
Acknowledgements

• Dr. Juan Agui
• Dr. M. David Kankam and the University Programs
  Office
• Dr. Paul Hambourger (CSU)
• Dr Suleyman Gokoglu
• Nasser Rashidnia
• Oregon Space Grant