rover egress design progress report 9/26/2011 anton galkin zack morrison hahna alexander 1
TRANSCRIPT
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ROVER EGRESS DESIGNPROGRESS REPORT9/26/2011
Anton GalkinZack MorrisonHahna Alexander
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Progress Report
Semester Schedule Research of Design Constraints Initial Design Concepts Comparison of Designs Selected Design Path Test Plan
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Semester Schedule
Presentations
Research
CAD Work
Model Validation
Cost Estimate
Order Parts
Fabrication
Testing
Lander Integration
Final Report Due
Research
CAD Work
Model Validation
Cost Estimate
Order Parts
Fabrication
Testing
Lander Integration
Final Report Due
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Research: Launch Dynamics
Static Loads: +6G/–2G axial ±2G lateral
Dynamic loads: MIN: 20G at 100Hz MAX: 3000G at 2000Hz
Vibration: Fundamental vibration modes do
not couple with Falcon 9 rocket Precision components held in
place by friction can become misaligned
Center of Gravity Lateral Offset: MAX 0.5in spin-stabilized mission MAX 5.0in non-spin stabilized
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Research: Vacuum Space FlightThermal regulation through radiation only
High voltage charge can accumulate on spacecraft Voltage potential over non-conducting (e.g.
composite) surfaces Uncontrolled discharge can damage spacecraft
Ultraviolet radiation detrimental to many materials Polymer erosion & out-gassing can contaminate
spacecraft Stripping of oxidation layer can cause cold welding
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Temperature Variation
-1 0 1 2 3 4 5 6 7
-150
-100
-50
0
50
100
150
200
250
300
Pre-Launch: 70°F
Launch: 200°F Space: -100°F
to +170°F
Lunar Day: 176°F to
253°F
Time (Days)
Temp (°F)
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Material Selection
Aluminum Titanium Composite (carbon fiber & aluminum
honeycomb)
0
50
100
150
200
250
300
350
400
450
237
22
100
300
Thermal Conduc-tivity (k, W/m°K)
Alum
inum
Tita
nium
Compo
site
0
5
10
15
20
25
23
8
2
20
Thermal Ex-pansion
(αv x10-6K-1)
Aluminum Titanium Composite0
0.050.1
0.150.2
0.250.3
0.350.4
0.450.5
0.04
0.13
0.45
0.03
Emissivity (ε) & Absorp-tivity (α)
?
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Design Concepts
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Design Concepts
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Design Concepts
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Design Concepts
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Design Concepts
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Design Comparison Chart
1. Dual Direction Ramp2. Segmented Ramp
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Comparison to Segmented Design
Tele
scopin
g R
am
p
Dual D
irect
ion R
am
p
Roll-u
p
Rope L
adder
Tensi
on A
ssem
bly
Show
er
Curt
ain
Ram
p C
hute
Sci
ssor
Arm
Rota
ting A
rm
-40
-35
-30
-25
-20
-15
-10
-5
0
5
Rati
ng
Com
pare
d t
o
Seg
men
ted
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Test Plan – Deployment
Deployment Reliability
Successful Deployment
Landing Accuracy
Deployment Time
Geometric Constraints
Deployment Angle
Stress/Deflection
Component Failure
Impact Force
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Test Plan – Egress
Egress Reliability Egress Success
Stress/Deflection
Joint Failure
Wheel-Ramp Interaction
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Test Plan – Landing Conditions Lander Tilt – Deployment Reliability
Lunar Terrain – Deployment, Egress Reliability Worst Case 30cm Rocks/Holes
Ground-Hole Ground-Rock Rock-Rock Hole-Hole Rock-Hole
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Questions?