contamination control for thermal engineers...tfaws 2015 – august 3-7, 2015 25 surface...
TRANSCRIPT
![Page 1: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/1.jpg)
GSFC· 2015
Contamination Control
for Thermal Engineers
Rachel Rivera
NASA/GSFC/Code 546
TFAWS 2015 – August 3-7, 2015 1
![Page 2: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/2.jpg)
Agenda
• Contamination Overview
• Effects of Contamination on Flight Hardware
• Contamination Requirements
• Design Methodology
• Integration and Testing
• Launch Site Support
• Contamination Control & Prevention
TFAWS 2015 – August 3-7, 2015 2
![Page 3: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/3.jpg)
Contamination Overview
TFAWS 2015 – August 3-7, 2015 3
![Page 4: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/4.jpg)
Contamination Overview
There are 2 types of Contamination
Molecular Contamination on a Si Wafer
Particulate contamination on Radiators
• Particulate: dust, debris, skin cells, fibers
•Molecular: films, greases, skin oils, ice
TFAWS 2015 – August 3-7, 2015 4
![Page 5: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/5.jpg)
Contamination Overview (Cont)
In order to mitigate performance degradation of space flight hardware caused by contamination, a Contamination Control Program is established on the Mission. – Understand the design: what are the critical components, what are
their sensitivities, and their performance requirements
– How can the S/C & instrument design help mitigate contamination
– Establish a Contamination Control Program
– Implement contamination control protocols
– Clean, monitor, verify, and maintain cleanliness
TFAWS 2015 – August 3-7, 2015 5
![Page 6: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/6.jpg)
•Meet Mission and Science Objectives
• Maintain Long-Term Hardware Performance
• Prevent Against Cross-Contamination Across the S/C
• Maintain Cleanliness Levels
•Why are Contamination Requirements Important?
• Meet Mission Success
MISSION SUCCESS!!!
Why do we Have Contamination Requirements?
TFAWS 2015 – August 3-7, 2015 6
![Page 7: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/7.jpg)
Summary of Spacecraft Contamination Problems
TFAWS 2015 – August 3-7, 2015 7
![Page 8: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/8.jpg)
On-Orbit CC Issues
o TIRS Instrument on LDCM has a 25 micron particle on its
filter, 4% performance degradation
TFAWS 2015 – August 3-7, 2015 8
![Page 9: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/9.jpg)
CC By Design
TFAWS 2015 – August 3-7, 2015 9
![Page 10: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/10.jpg)
The Contamination Control Approach
TFAWS 2015 – August 3-7, 2015 10
![Page 11: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/11.jpg)
Contamination Control Flow Chart
TFAWS 2015 – August 3-7, 2015 11
![Page 12: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/12.jpg)
Contamination Effects
TFAWS 2015 – August 3-7, 2015 12
![Page 13: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/13.jpg)
Satellite Example: Lunar Reconnaissance Orbiter
X
Z
Y
HIGH GAIN
ANTENNA
SYSTEM
INSTRUMEN
T MODULE
SOLAR ARRAY
SYSTEM
PROPULSION
MODULE
ISO-THERMAL
PANEL/RADIATOR
SPACECRAFT
BUS
TFAWS 2015 – August 3-7, 2015 13
![Page 14: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/14.jpg)
Contamination Effects on Hardware Performance
• Particle
– Obscuration
– Absorption
– Scattering
– Mechanical Interference, sticking, clogging
– systems and moving mechanisms
– If conductive, shorting
• Molecular
– Absorption (affects transmission, reflectance)
– Scattering (dependent upon deposition pattern)
– Sticking in mechanical mechanisms
– Corrosion during ground operations can cause particulates
Particle on a surface causing
obscuration and scatter.
TFAWS 2015 – August 3-7, 2015 14
![Page 15: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/15.jpg)
Impacts of Contamination Effects
Particle Effects:
• Affects Signal Strength:
Reflective Mirrors/Detectors/
Micro-Channel Plates
• Scatter:
Optical Baffles/Mirrors/Lens
• Obscuration:
Radiators/ Thermal
Coatings/Mirrors
• Absorption of Energy:
Solar Cells/ Thermal Coatings
LROC
NACs
Radiators
Star
Tracker
Baffles
LROC
Cameras
LOLA
Laser LAMP UV
instrument
LRO Instrument Module
TFAWS 2015 – August 3-7, 2015 15
![Page 16: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/16.jpg)
Impacts of Contamination Effects (Cont)
Molecular Effects:
• Affects Signal Strength:
Absorbed Laser Energy/Lens
•Scatter & Obscuration :
Optics/Mirrors/Lens
Radiators/ Thermal Coatings
• Absorption of Energy:
Solar Cells/ Thermal heating
of Coatings/Lens/Optics
• Synergistic Effects
Laser and beam wordassociation1.net/action.html
TFAWS 2015 – August 3-7, 2015 16
![Page 17: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/17.jpg)
Contamination Requirements
![Page 18: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/18.jpg)
Introduction to Hardware Contamination Requirements
• Sensitive hardware and instruments drive contamination requirements – Not all hardware is sensitive to contamination, however all hardware still
possess contamination requirements in order to avoid cross-contamination
• There are 2 main types of contamination requirements on flight hardware:
– Surface cleanliness levels:
• Molecular requirements- films, greases, skin oils
• Particulate requirements- dust, debris, skin cells
• Visibly Clean
– Outgassing requirements:
• Bake-outs are required in order to meet molecular outgassing flux levels
TFAWS 2015 – August 3-7, 2015 18
![Page 19: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/19.jpg)
Hardware Contamination Requirements
1. Particle Distribution: Size and Count yield
Cleanliness Level
2. Surface Obscuration: Percent Area Coverage (PAC)
= Total Area of Particles*100
Total Surface Area
Particles on a surface using Image Analysis
1.E+00
1.E+01
1.E+02
1.E+03
1.E+04
1.E+05
1.E+06
1.E+07
10 100 1000
Diameter, Microns
Pa
rtic
les
pe
r 0
.1 m
2
A-1Level 200Level 400Level 600
Log N = 0.926(Log2 L – Log2 X)
N = Amount of Particles in 0.1m2
X = Particle Size L = Cleanliness Level
Log-Normal Distribution with Product Cleanliness Level
(Dave Hughes)
Surface Particulate Cleanliness Levels per IEST-STD-CC-1246D
TFAWS 2015 – August 3-7, 2015 19
![Page 20: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/20.jpg)
Hardware Contamination Requirements (Cont)
Surface Molecular
Cleanliness Levels per
IEST-STD-CC1246D
Molecular NVR amount
on a given surface area
Level
Limit, NVR
mg/0.1m2 (or
g/cm2)
A/100
A/50
A/20
A/10
A/5
A/2
A
B
C
D
E
F
G
H
J
0.01
0.02
0.05
0.1
0.2
0.5
1.0
2.0
3.0
4.0
5.0
7.0
10.0
15.0
55.0 Surface molecular contamination www.atp.ie/
TFAWS 2015 – August 3-7, 2015 20
![Page 21: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/21.jpg)
Molecular Contamination
TFAWS 2015 – August 3-7, 2015 21
![Page 22: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/22.jpg)
On-Orbit Effects
![Page 23: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/23.jpg)
On-Orbit Effects of Particulate Contamination
On orbit, particle movement and redistribution mechanisms differ from those normally encountered on the ground
– In space, there are fewer direct forces (wind, air flow disturbances, movement) to move particles around
– In space, movement and redistribution are caused primarily caused by
• Launch ascent depressurization (Air rushes out of vents) • Greatly reduced gravitational forces (Everything “floats” -- No
hiding dirt under the carpet or in the corner!) • Absence of air pressure • Charging
Information provided by Therese Errigo TFAWS 2015 – August 3-7, 2015 23
![Page 24: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/24.jpg)
On-Orbit Effects of Molecular Contamination
• On-Orbit molecular effects are more of a concern than particulate (molecular transport analysis)
• On the ground, Non-Volatile Residue (NVR) or Molecular Contamination deposits result from two phenomena – contact with a contaminated or contaminating surface or material — contact
transfer from fingerprints, adhesive tape, etc
– condensation of airborne molecular organic contamination
• volatile (gaseous) organic hydrocarbons (VOC): paint, adhesives, machine lubricating greases
• On orbit, NVR / molecular films result when materials outgas from one surface and deposit on another, usually cooler, surface.
• Contaminants inside electronic boxes can outgas and exit through the vents and deposit on colder surfaces. This is induced more due to the vacuum of space.
Information provided by Therese Errigo TFAWS 2015 – August 3-7, 2015 24
![Page 25: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/25.jpg)
Molecular Outgassing and Deposition
TFAWS 2015 – August 3-7, 2015 25
Surface
Contamination
Source
Rough Surface
Higher electrical potential
Higher surface area
Both increase deposition
rates
Solar UV
Increases outgassing
Increases deposition
Polymerizes deposits
Not factor for cruise
IS Factor on Mars
Collector
Contamination sensitive surface
If temperature collector < temperature source, deposition occurs
If UV light or chemical attraction, deposition enhanced
If temperature of collector is increased, evaporation and cleaning
Backscatter causes
Self-contamination
Diffusion limited hi-outgas molecule
Non-outgassing molecule at temperature T
Information provided by Therese Errigo
A Few Mechanisms for Vacuum Transport
![Page 26: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/26.jpg)
Molecular Effects
TFAWS 2015 – August 3-7, 2015 26
![Page 27: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/27.jpg)
Molecular Effects Continued
TFAWS 2015 – August 3-7, 2015 27
![Page 28: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/28.jpg)
Molecular Effects Continued
TFAWS 2015 – August 3-7, 2015 28
![Page 29: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/29.jpg)
Molecular Sources
TFAWS 2015 – August 3-7, 2015
Contamination Sources
29
![Page 30: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/30.jpg)
Outgassing
TFAWS 2015 – August 3-7, 2015
Diffusion
30
![Page 31: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/31.jpg)
Time Dependence of Materials Outgassing
TFAWS 2015 – August 3-7, 2015 31
![Page 32: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/32.jpg)
Hardware Contamination Requirements
Example of ambient air offgassing
www.glare-x-plus.com
Outgassing Requirements require hardware bakeouts in order to meet molecular
flux levels. Molecular flux levels are derived through molecular transport
analysis based on field of view to sensitive components, chemical constituent of
hardware, and the amount of outgassing species.
MOLEKIT2 Test, Pennzane 2001 Oil in Al Holder @30oC, QCM4 Deposition @-20
oC
4090
4095
4100
4105
4110
4115
4120
4125
4130
4135
4140
4145
4150
4155
4160
4165
4170
20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72
Test Run Time, Hours
QC
M F
req
uen
cy,
Hert
z
-20.6
-20.5
-20.4
-20.3
-20.2
-20.1
-20
-19.9
-19.8
-19.7
-19.6
-19.5
-19.4
-19.3
-19.2
-19.1
-19
20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72
QC
M T
em
pera
ture
, D
eg
rees C
els
ius
QCM4 Temperature
QCM4
Frequency
M2EC
Into M2
Chamber
Set to
50oCRGA Filament
Emission
Set to 0.1mA
M2EC
Out of M2
Chamber
Outgassed
Molecules
TFAWS 2015 – August 3-7, 2015 32
![Page 33: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/33.jpg)
Outgassing
TFAWS 2015 – August 3-7, 2015 33
![Page 34: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/34.jpg)
Other Contamination Sources
TFAWS 2015 – August 3-7, 2015 34
![Page 35: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/35.jpg)
Hardware Contamination Requirements (Cont)
Surface Visibly Clean Levels
per JSC-SN-C-0005
VC Level Incident Light
Level
Observation Distance Remarks
Standard 50 foot-candles 5 to 10 feet (2) (3) (5)
Sensitive 50 foot-candles 2 to 4 feet (2) (3) (5)
Highly Sensitive
Plus UV
50 foot-candles 6 to 18 inches (3) (4)
A visually clean surface free of physical
debris as seen without optical aids (except
corrected vision)
Visual Inspection
TFAWS 2015 – August 3-7, 2015 35
![Page 36: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/36.jpg)
Contamination Modeling
• Thruster Impingement: Plume Analysis
• Atomic Oxygen Effects
• Mass Transport Analysis
• Particle Redistribution Analysis
• Venting Analysis
• MOLKIT Analysis
TFAWS 2015 – August 3-7, 2015 36
![Page 37: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/37.jpg)
S/C Design Methodology
TFAWS 2015 – August 3-7, 2015 37
![Page 38: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/38.jpg)
Material Screening
Material Screening Criteria per ASTM E595
• Low Outgassing: Total Mass Loss (TML) <1%, Collected Volatile Condensable Materials (CVCM) < 0.1%
• Water Vapor Regain (WVR) considered
Information provided by Therese Errigo TFAWS 2015 – August 3-7, 2015 38
![Page 39: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/39.jpg)
Outgassing Parameters of Typical Spacecraft Materials
TFAWS 2015 – August 3-7, 2015 39
![Page 40: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/40.jpg)
Material Screening Continued
• ASTM E 1559: Measure molecular outgassing with
TQCM (MOLKIT)
TFAWS 2015 – August 3-7, 2015 40
![Page 41: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/41.jpg)
QCMs
TFAWS 2015 – August 3-7, 2015 41
![Page 42: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/42.jpg)
Outgassing Measurements
TFAWS 2015 – August 3-7, 2015 42
![Page 43: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/43.jpg)
Contamination Transport
TFAWS 2015 – August 3-7, 2015 43
![Page 44: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/44.jpg)
Molecular Contamination Transport
TFAWS 2015 – August 3-7, 2015 44
![Page 45: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/45.jpg)
Material Mitigations
• Low Particulating (minimize / avoid bare aluminum,
woven textiles, Velcro)
• Avoid materials detrimental to your sensitive
components (Silicones, Helium) • Minimize quantity of organics (minimize thickness, bond
lines) • Bakeout under vacuum to reduce outgassing
TFAWS 2015 – August 3-7, 2015 45
![Page 46: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/46.jpg)
On-Orbit Mitigations
TFAWS 2015 – August 3-7, 2015 46
![Page 47: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/47.jpg)
• Keep sources of organics out of line of sight of
optics/inlets
• Get electronics out of optic cavities whenever possible
• Keep main apertures sealed
• Isolate hazards from sensitive items (e.g., barriers, baffles, doors, covers, vents, etc.) and direct venting into non-sensitive areas
• On-Orbit Deployable Covers/Doors
• Red-Tag Covers
S/C Design Configuration
Slide by Therese Errigo TFAWS 2015 – August 3-7, 2015 47
![Page 48: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/48.jpg)
• Venting – direct effluent away
from apertures/inlets – MLI flaps
• Minimize number of potential vents / unintentional vents; use directional venting
• Use molecular adsorbers • Seal Honeycomb Edges • Purge interface/Manifold
on S/C for T-0 purging
Other S/C Design Methodologies
SDO Vents/Adsorbers
are also cost saving to reduce bakeout time
TFAWS 2015 – August 3-7, 2015 48
![Page 49: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/49.jpg)
• Selection of Thermal Control Coatings
– sources lower temperature than collectors (sensitive surfaces)
– provisions to heat contaminated surfaces so they release condensed contaminates (decontamination heaters)
• UV
– avoid / minimize UV impingement (direct sun or albedo) on optics or surfaces in line of sight or near of optics/sensitive surfaces; darken optics
• Atomic Oxygen
– avoid use of silicones in orbits with significant atomic oxygen
– Design with enough material to meet errosion rate, e.g. Kapton, Teflon
• Plume / vents
– direct all thruster plume and backscatter away from sensitive surfaces
– use high purity fuel
– Plume analysis determines impact
Information provided by Therese Errigo
Other S/C Design Methodologies
TFAWS 2015 – August 3-7, 2015 49
![Page 50: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/50.jpg)
CC on Thermal
TCS Slides by Phil Chen TFAWS 2015 – August 3-7, 2015 50
![Page 51: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/51.jpg)
Reflecting or Radiating Surfaces
TFAWS 2015 – August 3-7, 2015 51
![Page 52: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/52.jpg)
Reflective Surfaces
TFAWS 2015 – August 3-7, 2015 52
![Page 53: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/53.jpg)
Absorption
TFAWS 2015 – August 3-7, 2015 53
![Page 54: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/54.jpg)
Absorption Coefficient of Contaminants
TFAWS 2015 – August 3-7, 2015 54
![Page 55: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/55.jpg)
Absorption Coefficient of Contaminants
TFAWS 2015 – August 3-7, 2015 55
![Page 56: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/56.jpg)
Absorption Coefficient of Contaminants
TFAWS 2015 – August 3-7, 2015 56
![Page 57: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/57.jpg)
On-Orbit Solar Absorption Changes
TFAWS 2015 – August 3-7, 2015 57
![Page 58: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/58.jpg)
Contamination Effect on Equilibrium Temperature
TFAWS 2015 – August 3-7, 2015 58
![Page 59: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/59.jpg)
Molecular Contamination Effects on Emittance
TFAWS 2015 – August 3-7, 2015 59
![Page 60: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/60.jpg)
Effects on Surfaces
TFAWS 2015 – August 3-7, 2015 60
![Page 61: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/61.jpg)
Effects on Specularity
TFAWS 2015 – August 3-7, 2015 61
![Page 62: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/62.jpg)
Effects on Transmitting Surfaces
![Page 63: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/63.jpg)
Effects on Transmitting Surfaces
TFAWS 2015 – August 3-7, 2015 63
![Page 64: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/64.jpg)
Effects on Cryogenic Surfaces
![Page 65: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/65.jpg)
Contamination on Cryogenic Surfaces
TFAWS 2015 – August 3-7, 2015 65
![Page 66: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/66.jpg)
Contamination on Cryogenic Surfaces
TFAWS 2015 – August 3-7, 2015 66
![Page 67: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/67.jpg)
Particulate Effects on TCS
![Page 68: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/68.jpg)
Effects of Particles
TFAWS 2015 – August 3-7, 2015 68
![Page 69: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/69.jpg)
Reflecting of Thermal Control Surfaces
TFAWS 2015 – August 3-7, 2015 69
![Page 70: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/70.jpg)
Reflecting of Thermal Control Surfaces
TFAWS 2015 – August 3-7, 2015 70
![Page 71: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/71.jpg)
Reflecting of Thermal Control Surfaces
TFAWS 2015 – August 3-7, 2015 71
![Page 72: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/72.jpg)
Reflecting of Thermal Control Surfaces
TFAWS 2015 – August 3-7, 2015 72
![Page 73: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/73.jpg)
Surface Obscuration Effects on Solar Arrays
TFAWS 2015 – August 3-7, 2015 73
![Page 74: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/74.jpg)
Common Spacecraft Materials
TFAWS 2015 – August 3-7, 2015 74
![Page 75: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/75.jpg)
Contamination Effect on Equilibrium Temperature
TFAWS 2015 – August 3-7, 2015 75
![Page 76: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/76.jpg)
Contamination Effect on Equilibrium Temperature
TFAWS 2015 – August 3-7, 2015 76
![Page 77: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/77.jpg)
Thermal Control Hardware
TFAWS 2015 – August 3-7, 2015
Thermal Hardware
77
![Page 78: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/78.jpg)
Contamination Control and
Prevention
TFAWS 2015 – August 3-7, 2015 78
![Page 79: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/79.jpg)
Contamination Control during Assembly
Establish Contamination Control Plan (CCP)
General cleanliness should be maintained during manufacturing and assembly
• Parts should be cleaned prior to assembly and as they become soiled
• Components should be cleaned prior to becoming inaccessible
• Machining/Welding/Soldering/Abrading: Should include vacuuming, wipe down
• Lubricant/Cutting Oils: Excess should be wiped
• Coatings Application: On a cleaned surfaces
• Assembly should be done in a clean area where possible and gloves should be worn
TFAWS 2015 – August 3-7, 2015 79
![Page 80: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/80.jpg)
Facility and Personnel Requirements
SSDIF
Building 29 Class 10,000/ISO 7
Temperature/Humidity
Control
Full Cleanroom attire
Facility Requirements per FED-STD-209E or
ISO-14644-1
Clean facilities help maintain cleanliness levels and
standards
Cleanroom Garments help mitigate contamination
Spacecraft Systems Development and Integration Facility
(SSDIF)
Garmenting Requirements
TFAWS 2015 – August 3-7, 2015 80
![Page 81: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/81.jpg)
Contamination Control Overview Environmental Testing
• Mechanical Tests (Additional Localized Covers for Sensitive Surfaces)
– Vibration – Bag and Purge
– Shock – Bag and Purge
– Acoustic – Bag and Purge
– Mass Properties – Perform in Cleanroom or Bag and Purge
– Spin Balance (Launch Site) – Soft Covers for Apertures/Requires Class 10k
Environment (Spacecraft Pursing)
• Thermal Vacuum Bakeout and Testing
– Chambers Certified for Surface Cleanliness and Outgassing (TQCM, RGA, Cold Finger
Analysis)
– Use of Barriers (Bakeout Box, Tents, Bagging, Covers) to Prevent Particle Fallout
– Scavenger Plate; Cold Finger
– Slow Re-Pressurization
– Use of Bakeout Boxes (Shroud Within a Shroud)
• EMI
– Bagging/Purging to Greatest Extent Possible/Internal
Covers for Optics
– Class 10k Facility, Protect Apertures.
Slide by Therese Errigo TFAWS 2015 – August 3-7, 2015 81
![Page 82: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/82.jpg)
Facility Contamination Controls
• All equipment shall be cleaned before entering any cleanroom or cleantent – This includes GSE, ladders, scaffolds, dollies, tools
– A precision cleaning area shall be provided
– Before entering the clean area remove the outer bag in the anteroom and remove the inner bag in the cleanroom/cleantent.
– Large items needing cleaning should be scheduled well ahead of time and coordinated with Contamination Control.
• Cleanroom paper must be used for all WOAs and papers entering a clean area
• Materials brought into the cleanroom shall be cleanroom compatible, if uncertain, contact Contamination Control
• Cleanroom doors and cleantent entrances should not be opened unless all hardware in the room/tent is in a safe configuration
• Access Restrictions: Required GSFC Code 540 Cleanroom Certification Course
• Manloading Restrictions
• Work downstream of airflow
TFAWS 2015 – August 3-7, 2015 82
![Page 83: Contamination Control for Thermal Engineers...TFAWS 2015 – August 3-7, 2015 25 Surface Contamination Source Rough Surface Higher electrical potential Higher surface area Both increase](https://reader034.vdocuments.net/reader034/viewer/2022043001/5f7841ffcf0e124dab6c2142/html5/thumbnails/83.jpg)
Personnel Control Reminders
• Dust collects even within cleanrooms
• Fingerprints can not be completely removed by an alcohol wipe, and on many materials can etch the surface causing permanent changes to the surface properties.
• Particles that reside on a surface for a long period of time are harder to clean off.
• No make-up, perfume, or after shave are allowed in the clean area
• PEOPLE ARE DIRTY
Particle
Generation
TFAWS 2015 – August 3-7, 2015 83