SME Initiative
Materials and Processes
Space Environment Effects : Manned Volumes
NUM EROUS PROBLEM S
P A R T IC U L A R L Y
IN S U L A T IO N /
G A S K E T IN G
D E G R A D A T IO N O F
M A T E R IA L F U N C T IO N
O F F G A S S IN G /A G E IN G /
C O R R O S IO N
L IF E S U P P O R T IN G
A T M O SP H E R E
C O M B U S T IO N
B IO L O G IC A L
GROW TH
T O X IC G A S E S
L O S S O F M A T E R IA L
F U N C T IO N
T O X IN E S
A G R E S S IO N S T O
L IF E
C A T A S T R O P H IC
F A IL U R E S
D IS E A S E S
SM ELL
D IS C O M F O R T
Materials and Processes Division
ESA/ESTEC/TOS-QM
Mve/qmc 1
SME Initiative
Materials and Processes
Offgassing
Materials and Processes Division
ESA/ESTEC/TOS-QM
Mve/qmc 2
SME Initiative
Materials and Processes
Offgassing test (1)
ECSS-Q-70-29 (former ESA PSS-01-729) : The determination of offgassing
products from materials and assembled articles to be used in a manned space
vehicle crew compartment
Purpose:
Determine the identity and quantity of volatile offgassed products
from materials and assembled articles.
Material screening test
• Quantity of Carbon Monoxide [mg/g]
• Quantity of total organics (pentane equivalent) [mg/g]
• Identification of contaminants in excess of 10 mg/g of material
General test for materials/assembled articles
• Identification and quantification of all contaminants present
• Use of T-values for acceptance
Materials and Processes Division
ESA/ESTEC/TOS-QM
Mve/qmc 3
SME Initiative
Materials and Processes
Offgassing test (2)
• Acceptance Limits
• Screening test
– Carbon Monoxide : <25 mg/g material
– Total Organics : <100 mg/g material
• General test
– No definitive acceptability defined by this test. Data are evaluated
by the Safety Office of the relevant project
• for assessment of toxic hazard due to volatile
contamination evolved from the item under test
• for assessment of the impacts on the potential
toxicity of the total quantity of offgassed products
from all contaminant generating items for a given
mission
Materials and Processes Division
ESA/ESTEC/TOS-QM
Mve/qmc 4
SME Initiative
Materials and Processes
Offgassing test (3)
– Following primary acceptance criteria are relevant:
– The quantity of each individual offgassed product shall
result in a predicted Spacecraft concentration below the
SMAC value
– Toxic Hazard Index (T) shall not exceed 0.5. T is
determined by calculating the ratio of the projected
concentration of each offgassed product to its SMAC
value and summing up these ratios for all offgassed
products
T = C1/SMAC1 + C2/SMAC2 ..... + Cn/SMACn
Materials and Processes Division
ESA/ESTEC/TOS-QM
Mve/qmc 5
SME Initiative
Materials and Processes
Offgassing test Procedure (1)
General test conditions
• Temperature 50 C
• Atmosphere : synthetic air or clean/dry air
• Pressure : 1 Atmosphere at 50 C
• Duration : 72 hrs
• Mass (material) 5g/liter test volume
Sampling : +/- 250 ml gas on trap after max. 12 hrs recovery
to reach RT; flow rate sampling is +/- 25 ml/min.
Materials and Processes Division
ESA/ESTEC/TOS-QM
Mve/qmc 6
SME Initiative
Materials and Processes
Offgassing test Procedure (2)
Test chambers
Different facilities are available e.g.:
Heraeus ovens 128 and 718 liters
Glass bottles 1, 2.5 and 5 liters
Analyses:
Screening:
TO/CO
GC with Methaniser and Flame Ionisation Detector
General test
Pre-concentrated sampling
Desorption system : Model MW-1A from Rektorik (CH)
GC with DB5MS from JW column (60m, diam 0.25mm, film 0.25 mm)
Mass spectrometer model Profile from Kratos (UK)
Materials and Processes Division
ESA/ESTEC/TOS-QM
Mve/qmc 7
SME Initiative
Materials and Processes
Offgassing test Procedure (3)
Screening test
Materials and Processes Division
ESA/ESTEC/TOS-QM
Mve/qmc 8
SME Initiative
Materials and Processes
Offgassing test Procedure (4)
Materials and Processes Division
ESA/ESTEC/TOS-QM
Mve/qmc 9
SME Initiative
Materials and Processes
Odour Test
NASA-STD-6001 (former NHB 8060.1C)
Purpose
Determine if the odour is objectionable or revolting
• Odour of a material or assembled article is objectionable or revolting if
an average of 2.5 or higher on an odour characteristic scale is obtained
(0:undetectable, 1:Barely detectable, 2: Easely detectable, 3:
objectionable,4: revolting).
• Sample preparation is the same as for Offgassing test
• Test panel shall consist of 5 qualified persons
Materials and Processes Division
ESA/ESTEC/TOS-QM
Mve/qmc 10
SME Initiative
Materials and Processes
Flammability
Materials and Processes Division
ESA/ESTEC/TOS-QM
Mve/qmc 11
SME Initiative
Materials and Processes
Flammability configuration assessment (1)
• Identify flammable materials used, their amounts, thickness, exposed
surface, exposure environment
• Identify propagation paths for exposed materials (including housing)
• If configuration is container, evaluate its capability to contain an internal
fire
• If unacceptable configuration through the configuration
assessment, there are two options:
Use fire break concepts to reduce flammability hazard
by isolating the flammable materials
Conduct a test to show acceptability of configuration
Materials and Processes Division
ESA/ESTEC/TOS-QM
Mve/qmc 12
SME Initiative
Materials and Processes
Flammability configuration assessment (2)
A R E T H E R E A N Y F L A M M A B L E M A T E R IA L S O R M U L T IP L E
A P P L IC A T IO N S O F F L A M M A B L E M A T E R IA L S IN
AM OUNTS
> 0 .1 L B O R 1 0 S Q . IN C H IN M A N N E D C O M P A R T M E N T S
OR
> 1 .0 L B O R 1 2 L IN E A R IN C H E S IN O T H E R
COM PARTM ENTS?
NO
A CCEPTA BLE
YES
NO
U N A CCEPTA BLE;
M O D IF IC A T IO N
R E Q U IR E D
(S E E G U ID E L IN E S )
A R E E X T E R IO R S U R F A C E S A N D A N Y
E X T E R N A L L Y A T T A C H E D M A T E R IA L S
FLA M M A BLE?
YES
YES
C O U L D A F IR E P R O P A G A T E O N T H E S U R F A C E M O R E T H A N 6 ”
IN M A N N E D C O M P A R T E M E N T S O R 1 2 ” IN O T H E R
CO M PA RTM EN TS?
NO
NO
IS IT A C O N T A IN E R ?
A CCEPTA BLE
YES
YES
W IL L T H E C O N T A IN E R C O N T A IN A N Y IN T E R N A L F IR E ?
(S E E E X A M P L E C O N T A IN E R C A S E S )
A CCEPTA BLE
NO
U N A CCEPTA BLE;
M O D IF IC A T IO N
R E Q U IR E D
(S E E G U ID L IN E S
NO
A CCEPTA BLE
D O E S T H E C O N T A IN E R C O N T A IN A IR ?
YES
NO
A R E IN T E R N A L IG N IT IO N S O U R C E S P R E C L U D E D W H IL E
T H E C O N T A IN E R IS L O C A T E D IN T H E O R B IT E R ?
YES
Materials and Processes Division
ESA/ESTEC/TOS-QM
A CCEPTA BLE
Mve/qmc 13
SME Initiative
Materials and Processes
How to reduce flammability hazards
• Limitation of flammable materials by replacement with
a non flammable one
• Restriction of propagation paths through
Covering of flammable materials with a non
flammable one
Separation of flammable materials
(avoid propagation)
Materials and Processes Division
ESA/ESTEC/TOS-QM
Mve/qmc 14
SME Initiative
Materials and Processes
Upwards Propagation Test (1)
ECSS-Q-70-21 (Former ESA PSS-01-721) : Flammability testing for the
screening of space materials
Purpose :
Determine if a material, when exposed to a standard ignition source,
will self-extinguish and not transfer burning debris, which can ignite
adjacent materials
Test criteria :
Self extinguishing within 15 cm
No transfer of burning debris
Burn Propagation time
Sample dimensions : 300 x 64 mm, worst case thickness
Test atmosphere : depends on application (24% O2 or more…)
Materials and Processes Division
ESA/ESTEC/TOS-QM
Mve/qmc 15
SME Initiative
Materials and Processes
Upwards Propagation Test (2)
300 m m
64 m m
Test
S p e c im e n
Ig n ito r
N iC r
Materials and Processes Division
ESA/ESTEC/TOS-QM
Mve/qmc 16
SME Initiative
Materials and Processes
Upwards Propagation Test (3)
Materials and Processes Division
ESA/ESTEC/TOS-QM
Mve/qmc 17
SME Initiative
Materials and Processes
Upwards Propagation Test (4)
Materials and Processes Division
ESA/ESTEC/TOS-QM
Mve/qmc 18
SME Initiative
Materials and Processes
Wire Flammability test (1)
ECSS-Q-70-21 (Former ESA PSS-01-721) : Flammability testing for the
screening of space materials
Purpose :
Determine if a wire insulation system, when exposed to an external
ignition source, will self-extinguish and not transfer burning debris, which
can ignite adjacent materials
Acceptance criteria
Prior to flame application, while heating wire to maximal operation T, no
spontaneous combustion, splitting insulation nor baring conductor
During ignition and combustion no flaming droplets/particles
After burner is extinguished, cease flaming within 10 s and within a total
burn length of 150 mm
Sample dimensions : 5 x 1m
Test atmosphere : depend on application (20% O2 or more…)
Materials and Processes Division
ESA/ESTEC/TOS-QM
Mve/qmc 19
SME Initiative
Materials and Processes
Wire Flammability test (2)
Materials and Processes Division
ESA/ESTEC/TOS-QM
Mve/qmc 20
SME Initiative
Materials and Processes
Wire Flammability test (3)
Materials and Processes Division
ESA/ESTEC/TOS-QM
Mve/qmc 21