1. Ch. Durin, E. Laurent, DSO/AQ/MP S. Remaury, DSO/TB/TH
SPACEMON 2017 WORKSHOP CNES sensors for understanding the space environment and the effects on materials
Ch. Durin, E. Laurent, DSO/AQ/MP S. Remaury, DSO/TB/TH
Service AQ / MP
Présentation basée sur les présentations d’experts du domaine, F. Faye pour vide et contamination

2. Contents History Goals DEBRIS monitors ATOX monitors
THERMAL COATINGS AGEING monitors
Conclusions
Service AQ / MP
Présentation basée sur les présentations d’experts du domaine, F. Faye pour vide et contamination

3. The detectors are considered as passenger.
SPACEMON 2017 workshop – 13/12/2017
HISTORY
The CNES use detectors during operational spatial missions (SPOT, SAC-D) as well as on dedicated missions (LDEF, MIR, ISS).
The detectors are considered as passenger.
Detectors = specific sensors to monitor one of the parameters of the environment
Passive detectors and/or active monitors
Passive detectors have to be retrieved after flight in order to be analysed on ground
Spatial structures which in case of (control) return to the Earth can become a witnesses to measure the effects of the environment on materials.

4. Qualified multi missions
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HISTORY
The opportunities of flight being rather rare, the design of these experiments was optimized in order to be flight compatible and used on several carriers. The resources must be :
Mass/size limited
Power limited
Data’s flux limited
Cost reduce
Qualified multi missions

5. The main goals to use such detectors cover different aspects:
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OBJECTIVES
The main goals to use such detectors cover different aspects:
To improve our knowledge of our close environment in order to:
Better design our structures
To have better protection for human flight
To better understand the phenomena of synergy between several parameters of the environment
To supply entries for models of environment and for the design
To compare the flight data’s with the ground test
To optimize our ground tests and save cost

6. Particles from asteroids or comets V > 70 Km/s Continue back ground
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Debris Monitors
Particles from asteroids or comets
V > 70 Km/s
Continue back ground
Mass estimation 100 t/days
Particles from man activities = debris
Number increase >12000 big objects tracked
Today no system for “cleaning”
Life time in space
SPOT (825 x 825 km) 200 years
GEO orbit  Millenniums
High kinetic energy
Al sphere 1 mm at 10 km/s  perforation of an Al wall th. 4 mm
Collision recorded

7. Debris Monitors Impact on Al (MEDET) Impact on MLI (MEDET)
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Debris Monitors
Impact on Al (MEDET)
Impact on MLI (MEDET)
Impact on blanket (LDEF credit NASA)
Impact on solar cell (Hubble)

8. Current design (ONERA/CNES) consist 4 sensors and electronics box.
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Debris Monitors
SODAD
Active sensors based upon monitoring of the discharge of parallel plates capacitors during an impact.
Current design (ONERA/CNES) consist 4 sensors and electronics box.
Dimensions: 120 x 120 x 90 mm
Active surface 5.1 x 8 = 40.8 cm2
Sensitivity : 0.5 µm particle at 10 Km/s
Mass: 1 kg,
Power: 1 W

9. Status of SODAD activities on ISS Impacts prediction:
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Debris Monitors
Status of SODAD activities on ISS
Impacts prediction:
MASTER 2005 simulation: 400 km, I = 52°, RAM face, total MM+D  2500 impacts/m2/year = 10 impacts/year on SODAD for MMD≥1µm
Typical on ground results : Projectile : Carbonyl-iron, diameter = 0.4 to 1.2 μm.
In flight impact ( , RAM position): (F=10MHz)

10. Status of SODAD activities on ISS
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Debris Monitors
Status of SODAD activities on ISS
During the mission, 11 impacts have been detected. Distribution in time is not random and appears to be linked to peculiar events.
Post flight analysis have confirmed in flight results
Good behavior
Distribution in time of impacts observed during the exposure to space of SODAD-1

11. Status of SODAD activities on SAC-D Collaboration in CARMEN payload
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Debris Monitors
Status of SODAD activities on SAC-D
Collaboration in CARMEN payload
3 units have been used, pointing to 3 orthogonal directions
Impacts on Ram face:
36 impacts, resulting is: 2250 impacts/m2/year.
Impacts on Wake face:
2 impacts counted, resulting flux is: 120 impacts/m2/year,
Impacts on Zenith face:
1 impact counted, resulting flux is: 60 impacts/m2/year.
The flux measured on the wake and zenith faces are lower than expected

12. Cumulative impacts on detector 3 (+X) SODAD-2
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Debris Monitors
Status of SODAD activities on SAC-D
The global measured flux of micro-particles is lower than predictions given by the MASTER.
The distribution of the impacts in time is not random
Cumulative impacts on detector 3 (+X) SODAD-2

13. Status of passive experiments on ISS Need to be retrieved
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Debris Monitors
Status of passive experiments on ISS
Need to be retrieved
Increase surface detection (MLI)
Multi materials
Shape and chemical composition
Bloc
Optical
SEM 1 3 2 5 6
Total 9
Aerogel results summary
Very low density material ( g/cm3, suitable to collect almost intact particles for identification.

14. MLI au niveau du GS de l’ISS
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ATOX Monitors
ATOX (Atomic oxygen). Important for outside materials, linked with solar activities and degrade polymers and some metallic materials. The effects are crucial
For mechanical behavior (mass loss, structures embrittlement),
Thermo-optical properties of surfaces (modification of thermal balance),
Electrical conductivity (modification of charging), and contamination (molecular and particular).
MLI au niveau du GS de l’ISS
Kapton H
Teflon FEP

15. ONERA design and development under CNES R&T activity
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ATOX monitors
Resistak principle Measure the variation resistance of Kapton layers under AO
Device 3cmx4cm
Detection area ≈ 2cmx2cm
ONERA design and development under CNES R&T activity
Simple sensor, small device
Easy to operate (Labview interface for R acquisition),
Ready to flight

16. THERMAL COATINGS AGEING monitors
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THERMAL COATINGS AGEING monitors
Thermo-optical properties of a coating change with time in orbit:
Ageing due to UV
Contamination due to outgassing products
Erosion by atomic oxygen (ATOX) in low orbits
Flux of charged particles
The thermo-optical properties have a decisive impact on the thermal control definition (in particular: radiator size, temperature level and stability and heating power)
Ground testing allows to estimate the change, but it is difficult to combine all degradation factors with a representative way

17. THERMAL COATINGS AGEING monitors
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THERMAL COATINGS AGEING monitors
LDEF experiment : before/after 5,7 years in orbit

18. THERMAL COATINGS AGEING monitors
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THERMAL COATINGS AGEING monitors
THERME experiment principle: monitoring the temperature of the coating
The ageing of a coating is measured by its solar absorptivity increase
 Knowing the external environment seen by the coating and its temperature T given by THERME, it is possible to calculate its solar absorptivity αs evolution with time
THERME on Demeter

19. THERMAL COATINGS AGEING monitors
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THERMAL COATINGS AGEING monitors
THERME, a simple and a multi-missions experiment
Host satellites which supplies only:
Temperature sensors
Heating line(s) (in option)
Telemetry
Simple, adjustable and robust definition
Many versions of THERME (flexible or rigid for GEO)
Dimension and number of samples adjustable to the constraint (~300 g: mass of a « rigid » sensor with 4 samples)
Large qualification 20 years of flight heritage
32 flight sensors , 24 « flexible » versions and 8 « rigid » versions
113 tested samples of 28 different types
518 cumulated years of useful telemetry
2 industrial cooperations (Thalès & AirbusDS) / 2 international cooperations (Japan & Israel)

20. SPACEMON 2017 workshop
Conclusions
We have a lot of results using flight experiments not accessible from ground tests
Only in flight all synergetic effects can affect our materials
Each mission is a new lesson learned and give data's for future projects (choice and models)
Level of optimization made our monitors very operational
 Every flight opportunities and new cooperation's are welcome!

21. Thank for your attention
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Thank for your attention