EADS ' ~ rATllOemits.sso.esa.int/emits-doc/ASTRIUMSAS/ATLID/AO... · EADS '_~ aSCrlLJm . Title . rATllO. Ref : EC.RS.ASF.ATL.00035 Issue :5 Rev. : 001 Date : 12-03-2010 Page : i

L, EADS '_~

aSCrlLJm

Title

rATllO Ref : EC.RS.ASF.ATL.00035 Issue :5 Rev. : 001 Date : 12-03-2010 Page : i

CLEANLINESS REQUIREMENT SPECIFICATION FOR SUS CONTRACTORS

Name and Function Date Signature

Prepared by

Verified by

Anne TROUCHE

Cleanliness manager

Laurent MAZURAY

Industrial development manager

Lénaïc LE HORS

System engineering manager

March 12lh

2010

Approved by

Pierre THORAL

Product assurance manager Vf/1/IO

Authorized by Yves TOULEMONT

ATLID project manager

Document type

Specification

NbWBS Keywords

Cleanliness, contamination, requirement

.i'\hClrs 2309-l \:b\,\'ords ~21O © EADS/Astriumh1c~.lmc EC-RS-.\SF-.\TL-00035-IS;SUcS - .\TJ.1D de.lllhncss rcqwrcmClltll for sub.doç

Ref : EC.RS.ASF.ATL.00035 Issue : 5 Rev. : 001 Date : 12-03-2010 Page : ii

NbCars 23094 NbWords 4210 FileName EC-RS-ASF-ATL-00035-issue5 - ATLID cleanliness requirements for sub.doc

© EADS/Astrium

SUMMARY

The present document gives the requirements for the particulate and molecular contamination of ATLID Lidar instrument, part of Earthcare satellite. The allocations are given for units at equipments delivery.

Document controlled by Josette GALZIN

Ref : EC.RS.ASF.ATL.00035 Issue : 5 Rev. : 001 Date : 12-03-2010 Page : iii


© EADS/Astrium

DOCUMENT CHANGE LOG

Issue/

Revision Date Modification Nb Modified pages Observations

01/00 22-09-08 Initial issue 02/00 09-10-08 14 Add of description LIC test

19 Add of preliminary LIC test procedure (draft version)

03/00 04/03/09 8 Add of metallic particles 9 Polyurethane forbidden 10 Temperature correction 13 Add of particulate

contamination inspection 04/00 27/10/09 all Evolution due to the

change of configuration. New definition of the sensitive zones. Add of bake-out conditions

05/00 12/03/10 all Evolution due to the change of configuration.

05/01 29/03/10 8

Ref : EC.RS.ASF.ATL.00035 Issue : 5 Rev. : 001 Date : 12-03-2010 Page : iv


© EADS/Astrium

PAGE ISSUE RECORD Issue of this document comprises the following pages at the issue shown

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Ref : EC.RS.ASF.ATL.00035 Issue : 5 Rev. : 001 Date : 12-03-2010 Page : v


© EADS/Astrium

TABLE OF CONTENTS

1 GENERALITIES................................................................................................................................................. 1

1.1 SCOPE AND APPLICABILITY ...................................................................................................................................................... 1 1.2 REFERENCES .............................................................................................................................................................................. 1

1.2.1 Applicable documents ................................................................................................................................................................ 1 1.2.2 Normative references .................................................................................................................................................................. 1 1.2.3 Informative references ................................................................................................................................................................. 1

1.3 TERMS, DEFINITIONS AND ABBREVIATED TERMS ................................................................................................................. 2 1.3.1 Terms and definitions ................................................................................................................................................................ 2 1.3.2 Abbreviated terms ..................................................................................................................................................................... 2

2 DESCRIPTION OF ATLID ...............................................................................................................................4

2.1 BASELINE CONCEPT SUMMARY ................................................................................................................................................ 4 2.2 CONTAMINATION SENSITIVE ITEMS ........................................................................................................................................ 6

3 SURFACE CONTAMINATION REQUIREMENTS ......................................................................................7

3.1 GENERAL REQUIREMENTS ....................................................................................................................................................... 7 3.2 EQUIPMENT CONTAMINATION AT DELIVERY........................................................................................................................ 7 3.3 SELECTION OF MATERIALS AND PROCESSES .......................................................................................................................... 9

3.3.1 Materials selection ..................................................................................................................................................................... 9 3.3.2 Processes selection..................................................................................................................................................................... 11

4 GROUND ENVIRONMENT, OPERATIONS AND HANDLING ............................................................. 12

4.1 FACILITY GENERAL REQUIREMENTS..................................................................................................................................... 12 4.2 RULES FOR PERSONNEL .......................................................................................................................................................... 12 4.3 VACUUM TEST SPECIFIC REQUIREMENTS.............................................................................................................................. 13 4.4 MECHANICAL TESTS SPECIFIC REQUIREMENTS ................................................................................................................... 13 4.5 GROUND SUPPORT EQUIPMENT ............................................................................................................................................ 13 4.6 CLEANING AND DECONTAMINATION METHODS AND TOOLS .......................................................................................... 14 4.7 PACKING, TRANSPORTATION AND STORAGE....................................................................................................................... 14

4.7.1 Packing................................................................................................................................................................................... 14 4.7.2 Storage.................................................................................................................................................................................... 14

5 CONTAMINATION SOURCES...................................................................................................................... 15

5.1 MOLECULAR CONTAMINATION SOURCES............................................................................................................................. 15 5.2 PARTICULATE CONTAMINATION SOURCES........................................................................................................................... 16 5.3 TYPES OF CONTAMINANTS ..................................................................................................................................................... 16 5.4 TRANSPORT MECHANISMS ...................................................................................................................................................... 17

6 CONTAMINATION CONTROL.................................................................................................................... 17

Ref : EC.RS.ASF.ATL.00035 Issue : 5 Rev. : 001 Date : 12-03-2010 Page : vi


© EADS/Astrium

6.1 ROOM CONTAMINATION MONITORING ...............................................................................................................................17 6.2 HARDWARE CONTAMINATION MONITORING...................................................................................................................... 17

7 RESPONSIBILITIES........................................................................................................................................ 18

ANNEX 1 : LIC : CRITICAL ITEMS ....................................................................................................................... 19

Ref : EC.RS.ASF.ATL.00035 Issue : 5 Rev. : 001 Date : 12-03-2010 Page : 1


© EADS/Astrium

1 GENERALITIES

1.1 SCOPE AND APPLICABILITY

The present document gives the requirements for the particulate and molecular contamination of ATLID equipments, parts of ATLID Lidar instrument. The allocations are given for equipments at delivery.

1.2 REFERENCES

1.2.1 Applicable documents

[AD1] EC.RS.ASD.SY.00002 Product Assurance and Safety Requirements for subcontractors

1.2.2 Normative references

The following normative documents contain provisions which, through reference in this text, constitute provisions of this cleanliness requirement specification.

[SD1] ECSS-Q-ST-70-01 Cleanliness and contamination control

[SD2] ECSS-Q-70-71 Data for selection of space materials

[SD3] ECSS-Q-ST-70-02 A thermal vacuum test for the screening of space materials and processes

[SD4] ECSS-Q-ST-70-05 The detection of organic contamination of surfaces by infrared spectroscopy

[SD5] ESA-PSS-01-204 Particulate contamination control in clean rooms by particle fall-out measurements

[SD6] ISO 14644 Clean rooms and associated controlled environments

1.2.3 Informative references

The following documents, although not a part of this cleanliness requirement specification, amplify or clarify its content.

[RD1] EC-LI-ASF-ATL-00006 List of acronyms



© EADS/Astrium

1.3 TERMS, DEFINITIONS AND ABBREVIATED TERMS

1.3.1 Terms and definitions

Refer to [SD1].

1.3.2 Abbreviated terms

See also [RD1] document AIT Assembly, Integration & Test BSM Beam Steering Mechanism BSME Beam Steering Mechanism Electronic BEX Beam Expander BOL Beginning of life CCCP Cleanliness and contamination control plan CFRP Carbon fibre reinforced plastic CRS Contamination requirement specification CVCM Collected volatile condensable material DML Declared materials list DPL Declared processes list DRB Delivery review board DRD Document requirement description EIDP End item data package EOL End of life ERO Emitting-receiving optics FWHM Full width half maximum GSE Ground support equipment HEPA High efficiency particles airborne (filter) IPA Isopropyl alcohol LIC Laser-induced contamination LID Laser-induced damage LIDT Laser-induced damage threshold MGSE Mechanical GSE MOC Molecular contamination NVR Non volatile residue OGSE Optical GSE PAC Particulate contamination PFO Particles fall-out PPM Parts per million QCM Quartz crystal microbalance RLH Reference laser head RML Recovery mass loss RSP Rayleigh spectrometer



© EADS/Astrium

TML Total mass loss TV Thermal vacuum (test) VBQC Vacuum balance quartz crystal



© EADS/Astrium

2 DESCRIPTION OF ATLID

2.1 BASELINE CONCEPT SUMMARY

ATLID instrument is a direct detection Lidar for aerosol measurement. The source is a tripled YAG laser, which gives a monochromatic spectrum at 355 nm. The pulsed power reaches 30 mJ at transmitter output.

An overview of the satellite is given in figure 2.1-1.

The instrument is composed of a structure with the following subassemblies, shown in figure 2.1-2 :

• A stable sub-assembly made of a base-plate which holds the silicon carbide (SiC) telescope, the focal plane assembly (FPA) and the redundant Power Laser Heads (PLH). Emission beam runs across the instrument protected by a metallic baffle.

• The Reference Laser Heads (RLH), remote electrical units and the laser radiator, which are thermally and mechanically decoupled from telescope and optical bench.

The telescope is an afocal telescope made of two parabolas in sintered silicon carbide material. The primary mirror has a diameter of 620 mm, while the secondary mirror diameter is 21 mm.

The transmitter is based on a Power Laser Head (PLH) seeded by a Reference Laser Head (RLH). The YAG crystals are pumped with laser diodes. Photodiodes are used to monitor the signal. RLH and PLH boxes are connected with optical fibres in silica. The PLH is cooled by a dedicated thermal system. The latter features a radiator mounted on the anti-sun side of the platform. Two sets of laser heads are implemented on the main structure (cold redundancy). The PLH is built into a sealed box pressurised (1.2 bar).

The focal plane assembly includes optics and holds the HSR filter. The detectors are deported to the anti-sun wall and coupled to the focal plane by means of optical fibres. The detector is a Memory CCD (MCCD) optimised for UV sensitivity (thinned and backside illuminated).



© EADS/Astrium

Figure 2.1-1 : Overview of EarthCARE satellite

Figure 2.1-2 : Overview of ATLID instrument

CPR

ATLID

BRR MSI

PLH (pressurized)

Primary mirror

Secondary mirror

Metallic emission baffle

E-BEX

BEX output window

ATLID instrument

OIA YIA

XIA

ZIA



© EADS/Astrium

2.2 CONTAMINATION SENSITIVE ITEMS

The most contamination sensitive parts of ATLID instrument are the surfaces of the instrument, crossed by the laser power (ZONE A, see page 6 for the definition zone). On these surfaces, the particles will generate hot points, which could degrade optics coatings and even surfaces. From the experience got on lidars, we know that the molecular contamination is increased under the light power and particularly under UV harmonic. This photo-deposition effect, also called laser-induced contamination (LIC), increases the light absorption, which induces transmission loss and also substrate and coating heating. The photo-deposition is followed by the photo-degradation effect or the ablation effect, depending on beam fluence and deposit nature.

The most critical surfaces inside the PLH are those exposed to UV beam. The laser diodes are also very sensitive devices, whatever their power and wavelength are, due to the high irradiance generated onto their output facets.

The receiving optics have to withstand much less power. Therefore, the receive path is sensitive to contamination, due to the high number of optical surface involved, but it is not submitted to LIC phenomenon.

It is requested the manufacturer to perform LIC tests on samples to validate the selection of organics, refer to section 3.2.



© EADS/Astrium

3 CLEANLINESS REQUIREMENTS

3.1 GENERAL REQUIREMENTS

The general requirements about cleanliness are given in [AD1] section 4.5.8.

3.2 SPECIFIC REQUIREMENTS FOR EQUIPMENT CONTAMINATION AT DELIVERY

The requirement for ATLID equipment units at delivery depends on the sensitivity zone associated.

Therefore, criticality classes are defined here below.

Power laser head (PLH)

Beam expander

Beam steering

mechanism

Receiver Telescope

Power laser head (PLH)

Background filtering (BKGE)

Co-Alignment

Sensor (CAS)

HSR filtering (HSRE)

Mie co-polar

detector

Fibre Coupler Assemblies (FCA)

Rayleigh detector

Mie cross-polar

detector

Pressurised

ACDM(internal redundancy)

Instrument Detection Electronics (internal redundancy)

Emission BEX(E-BEX)

Atmosphere

Beam steering

mechanism

TLE

Blocking filter (BF)

RLHBSME

Transmitter Laser Electronics (TLE)

RLHRLH

PLH radiator

Loop HP

Emission baffle

Baffle

T° controlT° control

T° control

PC

DU

PC

DU

PC

DU

TM

/TC

Sci

ence

da

taReceiver

chainTransmitter

chain

fibre fibres

TMTC

ZONE A

ZONE B

ZONE C



© EADS/Astrium

Synthesis of equipment in accordance with critically classes :

ZONE A

ZONE B

ZONE C

- Power laser heads (PLHs)

- Beam steering mechanism

- Emission BEX (E-BEX)

- Emission baffle (internal face : to be confirmed)

- Reference Laser Head (RLH)

- Reception baffle

- Receiver telescope

- Blocking filter (BF)

- Background filtering (BKGE)

- HSR filtering (HRSE)

- Fibre coupler assemblies (FCA)

- MCCD + Detection & Fibre Assembly

- Co-Alignment Sensor (CAS)

- Instrument detection electronics

- Transmitter laser electronic

- PLH radiator

- Loop HP

- BSME

- ACDM



© EADS/Astrium

Following maximum levels are applicable at equipment delivery:

ZONE A

In critical units vicinity and in laser beam vicinity

ZONE B

In critical units vicinity and out of laser beam vicinity

ZONE C

Away from critical units

Molecular contamination

(mg/m²) 0.5 1 1

Particulate contamination

(PPM) 50 50 150

In zone A and zone B, special attention shall be paid to metallic particles (highly reflective). The size of these metallic particles is less than 10 µm which is about the limit for detection with unmagnified human eye using a bright fibre source.

3.3 SELECTION OF MATERIALS AND PROCESSES

3.3.1 Materials selection

* Specifications for Outgassing

To minimize the production of particles and condensable vapours, the materials used in spacecraft components have to be selected according to the lists of allowed materials from ESA, CNES or NASA.

Material outgassing data can be obtained from ESA Outgassing Data Base in Internet under http://esmat.esa.int/ or NASA GSFC Outgassing Data Base. The baseline requirement about material out-gassing is expressed in [SD2]. When tested as per [SD3], the materials out-gassing ratio have to be less than the following ones.

Materials which do not meet the above requirements (or which are considered as critical or which

are exposed to LASER flux), shall be submitted to vacuum bake out as next paragraph (or as per [AD1] section 8.3.1.)

Out-gassing ratio (%) CVCM RML

Zone C 0.1 1 Zone A and B 0.01 0.1



© EADS/Astrium

The minimum bake-out conditions shall be the followings: For materials in zone A:

• Vacuum conditions, Pressure < 10-4 mbar • Temperature ≥ 65°C • Duration ≥ 96 H

For materials not able to sustain such temperature conditions (i.e. epoxy, polyurethane), the followings can be applied:


For materials in zones B & C:


For materials not able to sustain such temperature conditions (i.e. epoxy, polyurethane), the followings can be applied:


Materials, for which no relevant out-gassing data are available, or that have shown batch variability, shall be subjected to an out gassing test as per [AD1] section 8.3.1.

* Cleanliness specifications

For cleanliness aspect, metals and glasses are generally preferred for their high surface resistance and their capability of low roughness, which prevents them from trapping contaminants.

Care shall be paid with certain matt paints, organic films and VELCRO attachment device, because they easily trap particles.

Silicone based and aromatic based materials shall be avoided as far as possible. They have to be requested via RFA.

Polyurethane shall be excluded from the design.



© EADS/Astrium

*LIC specifications

All organics in units in zone A, have to be selected regarding their LIC test result in UV band, see Critical items in Annex 1.

All materials which are not preferred in terms of LIC according Annex 1, will be avoided when it

is possible.

If it is not possible, selected materials will be baked in accordance with the parameters given in previous paragraph.

All flight materials have to be defined in DML as per [AD1] section 8.3.1. For the need of Astrium contamination analysis, an estimation of the mass in grams of the organics has to be provided.

3.3.2 Processes selection

The machining of mechanical parts has to be made without lubricant, or with a lubricant easily removed by standard solvents. Each part has to be cleaned before assembly by the manufacturer.

The design of each mechanical part has to be without sharp edge, to prevent metal barbs to be generated. The parts drawings have thus to specify a general bevel or chamfer.



© EADS/Astrium

4 GROUND ENVIRONMENT, OPERATIONS AND HANDLING

4.1 FACILITY GENERAL REQUIREMENTS

As per [SD1] annex F, each clean-room environment has to ensure a temperature of 22+/-3°C, a relative humidity of 55 +/-10 % and a slight overpressure with respect to surrounding rooms. Temperature and relative humidity have to be permanently recorded. Maintenance, control, cleaning and inspection of clean rooms shall be specified in internal guidelines.

As per [SD1] annex F, the molecular contamination rate of clean rooms shall be less than 0.5 mg/m²

(0.5 10-7 g/cm²) per week.

Units from zones A and B shall be manufactured, assembled and tested in class ISO 5 rooms or cabinet.

4.2 RULES FOR PERSONNEL

The personnel working in clean rooms shall be trained, to get access right, to wear specific garment, depending on class standard level, and to behave safely.

The manufacturer shall issue an internal standard (Cleanliness and Contamination Control Plan) which defines the general work conditions and rules to be met by operators. The document shall cover at least the following topics:

- The protective garments to be worn by the personnel in the facility - The permitted activities in the clean room - The maximum allowed number of personnel in the facility - Allowed and forbidden materials and products - Procedures for facility and tool preparation, cleaning and maintenance (including cranes) - Cleaning and handling procedures for the equipment units entering the facility



© EADS/Astrium

4.3 VACUUM TEST SPECIFIC REQUIREMENTS

The components and devices used inside the vacuum chamber have to meet the general out-gassing ratio for materials required in section 4. The whole inner surface of the chamber, each tool and device to be placed into the chamber during spacecraft test, shall be cleaned with a non aromatic solvent with low NVR.

A cold trap has to be used to trap the major part of the molecules.

A blank test has to be applied in the chamber using temperature and pressure profiles representative of flight hardware test. It has to be held over at least 24 h since the pressure level is reached. It shall be run just before the real thermal vacuum test in order to validate chamber cleaning and parameters setting (pressure and temperature profiles). During the blank test, each tool, cable and ancillary item, needed by spacecraft operation or by vacuum chamber operation, which is part of the test configuration during the real vacuum test, shall also be placed in the chamber for the blank test.

During each vacuum test, blank test and real one, the following cautions are taken:

- Molecular witness samples are placed in the chamber close to the hardware - The temperature of the radiant panels facing the flight hardware is monitored - A cold cryogenic panel is used in order to collect and trap all the out-gassed products - The chamber pressure is monitored all along the test, from pressure down to pressure up - The temperature before air refilling is set high enough and stabilized to avoid humidity condensation - The refilling is recommended using class TBD nitrogen up to TBD mbar - The air floated into the chamber, if any, is filtered with HEPA filter - The nitrogen or air input rate is set very slow to avoid to flow the potential already settled particles

The blank test is successful if the measurement of the contamination witness samples shows less

than 0.5 mg/m² molecular contamination. If unsuccessful, the blank test has to be run again after new overall cleaning.

4.4 MECHANICAL TESTS SPECIFIC REQUIREMENTS

The preparation of mechanical tests (accelerometer gluing…) and the tests have to be done in a class ISO5 room or tent. Particulate and molecular pollution from the vibration means can be high, particularly from the slipping device of the shaker, which generates oil drops and vapours. A protection bag has to be

fixed around the shaker.

4.5 GROUND SUPPORT EQUIPMENT

The GSE and tools used in the vicinity of sensitive surfaces, have to show the same cleanliness

level as the flight hardware. Therefore, the GSE have also to meet the general out-gassing ratio for materials required in section 3.2.

The GSE having to undergo a vacuum test together with flight hardware and having to be close to sensitive surfaces shall be baked-out and placed in the vacuum chamber during the blank test (see 4.3).



© EADS/Astrium

4.6 CLEANING AND DECONTAMINATION METHODS AND TOOLS

A cleaning process has to take into account the size, the access, the scratch sensitivity and the chemical sensitivity of the hardware surface. For ZONE A units, the cleaning with solvent has to be validated by a LIC test.

4.7 PACKING, TRANSPORTATION AND STORAGE

4.7.1 Packing

The packing materials to be selected shall not degrade the surface cleanliness level. It has to be at least as clean as the surfaces they protect and meet the out-gassing requirement from section 3.2. The materials

used for the equipment packing (plastic bag, foam…) have to be made with materials presenting

no free particles and no organic materials out-gassing.

The packing shall be described and specified in a procedure delivered in the hardware acceptance data package.

4.7.2 Storage

Secure storage areas compatible with the cleanliness requirements to store incoming materials, intermediate items and end items before shipping shall be provided.

The storage conditions shall be described and specified by a procedure delivered in the hardware acceptance data package.



© EADS/Astrium

5 CONTAMINATION SOURCES

5.1 MOLECULAR CONTAMINATION SOURCES

The molecular contamination results from the condensation of molecules on surfaces, under clusters or layers. They stick to the substrate under Van der Waals force or hydrogen link. The residence time depends on species and is extremely temperature dependent. The resulting thickness is commonly in the range of 0.1 to 100 nm. The molecular contamination is expressed in surface mass (mg/m2 or 10-7 g/cm²).

The off-gassing and out-gassing phenomena permanently occur in spacecraft organic materials from section 3.3:

- CFRP resin in the structural parts and in FPA base-plate

- Glue points in structural parts, in optics and on all screws

- Paint on instrument MLI inner side, some structural parts, FPA cover, some electronic boxes

- PCB varnish in all electronics

- Adhesive tapes for thermal or optical finishing on structural parts

- MLI film

- Cable insulator

The same occurs in GSE or in instrument close environment:

- Packing materials

- Test equipment bays

- Vacuum pump oil vapour (hazardous)

- Launcher fairing

Gaseous contaminant can also be released during some manufacturing or testing processes, which are potential sources of gaseous contamination:

- Solder flux

- Glue or paint components during application and before full polymerisation

The silicone compounds can contaminate surrounding areas by creeping effect, if they are not fully polymerised.

The hazardous handling with naked hands or dirty gloves can occur. A cleaning using not pure solvent would also let contamination residue (NVR) on surfaces after a cleaning tentative. Such hazardous contamination cases are definitely not considered here.



© EADS/Astrium

5.2 PARTICULATE CONTAMINATION SOURCES

The particulate contamination is an accumulation of solid particles (organic and inorganic) falling on surfaces or attracted by electrostatic forces. The big particles fall down easily under gravity, while the smallest (sub-micron size) undergo a Brownian movement until they hit and stick to a surface. The particles stick to the surface they hit under electrical forces. The common size range of concern is from 1 to 100 µm.

The main sources are the following: - Human dead skin cells, dead hair, cosmetics - Fibres and lint from clothing - Dust carried in on clothes

Other type of particles can come from the hardware itself: - Particles or flakes from paint - Particles from screw dry lubrication - Lint from MLI cutting - Wearing of mechanism

Particles can be released during some manufacturing or testing processes: - Particles from machining - Solder fume - Blowing of particles during vacuum test refilling - Redistribution during mechanical tests and transportation

During launch, particles can be released by the launcher fairing because of vibrations.

In flight during mission, the pyrotechnical devices are sources of particulate contamination, and also the micrometeorites. These sources will be neglected by the following due to low occurrence and lack of data.

5.3 TYPES OF CONTAMINANTS

Few data are available about the molecular contaminants out-gassed by organics. The IR spectrum of the molecular witness samples used on all space projects to monitor the contamination rarely allows to identify chemical species, but rather chemical families, like the most commonly seek as per [SD5]: hydrocarbon, ester, silicone...

The contamination from clean room environment is generally of hydrocarbon type. The materials used in ATLID instrument will have to be defined during the project development. The absorption at 355, 532 and 1064 nm of the contamination induced by material out-gassing has to be taken into account for the material selection, not only their out-gassing potential.



© EADS/Astrium

5.4 TRANSPORT MECHANISMS

The transport mechanisms of on-ground molecular contamination are mainly direct flux, reflected flux and ambient scattering. The creeping is the main transport mechanism of silicone species, particularly under monomer state before curing achievement. The transport mechanisms of in-flight molecular contamination are mainly direct flux, reflected flux and self-scattering into the instrument, ambient scattering also on surfaces in view of outer space. The importance of the various mechanisms depends on the contaminant species and on the geometry of the considered unit. Direct flux, reflected flux and self-scattering all occur together in cavities.

The best design solution against direct flux is the reduction of view factor between contaminant source and sensitive surface. The best design solution against self-scattering and reflected flux is the efficient venting of the cavity.

6 CONTAMINATION CONTROL

6.1 ROOM CONTAMINATION MONITORING

The environmental air of working areas has to be continuously monitored via airborne particles counter. The particles counter has to be placed in the activity area at hardware height.

The environmental air of working areas shall be validated before the manufacturing thanks to contamination witnesses.

6.2 HARDWARE CONTAMINATION MONITORING

The molecular and particulate contamination of units has to be monitored using witness samples, like PFO-plates for the particulate monitoring and IR crystal plates or metal plates for the molecular monitoring. The witness samples have to be fixed onto the units or placed very close to them, in order to get a representative result. The witness samples shall be analysed as per [SD5] and [SD4].

All sensitive surface shall be inspected with a bright fibre light and UV-source. Visual inspections shall be performed with naked eyes using both white source and UV source, to better detect dust and organic stain. According to ECSS Q-70-50 (to be issued) the sensitivity of naked eyes at 50 cm and under 1000 lux condition is about 300 PPM and 10 mg/m². If necessary, binoculars will be used.

The sampling plan of particulate and molecular contaminations has to be provided before flight model manufacturing in a dedicated Manual for the cleanliness management during AIT phases.



© EADS/Astrium

7 RESPONSIBILITIES

The Subcontractor has to answer the cleanliness requirements by a cleanliness plan, which may be a part of its PA plan. After approval by Astrium, the Subcontractor’s plan is applicable. The Subcontractor is responsible for the cleanliness state of the equipment units until delivery to Astrium and shall also ensure the self compatibility of its hardware with the contamination generated by itself. The Subcontractor shall assign a person responsible for all cleanliness topics. The equipment EIDP delivered by the Subcontractor shall include a cleanliness certificate of conformance.



© EADS/Astrium

ANNEX 1 : LIC : CRITICAL ITEMS

Chemical Composition Material(s) Manufacturer Preference Remarks

Kapton P224 Permacel Not Preferred

Scotch 5413 3M Not Preferred

Acrylic adhesive tapes

XC100 black Kapton Sheldahl Not Preferred

Attention is drawn to the requirement related to adhesive tapes in ECSS –Q-70-71A, clause11.5 “Precautions”, as this is particularly applicable for LIC risk reduction.

The amount of adhesive tape used is to be strictly

minimised.

CV1152 Nusil Technology Not Preferred




Silicone

DC93500 Dow Corning Preferred

Incorrect curing conditions can enhance the LIC risk

PR1564 Products Research & Chemical Corp. (Semco)

Not Preferred Polyurethane

Solithane 113 Uniroyal Chemical Not Preferred

Polyurethanes are to be avoided.



© EADS/Astrium

Chemical Composition Material(s) Manufacturer Preference Remarks

Araldite AV138 Ciba Polymers Not Preferred

Araldite HV998 Ciba Polymers Not Preferred

Scothweld EC2216 3M Not Preferred

A12 Armstrong Not Preferred

Epoxy

Stycast 2850F Emerson & Cuming Preferred

Incorrect curing conditions can enhance the LIC risk



© EADS/Astrium

DISTRIBUTION LIST

ASF Copy ASF Copy ESA Copy

Toulemont, Yves x Thoral, Pierre X Lefebvre, Alain

Archer, Julien x Tonon Claire x Chahoud, Olivier

Barthe, Patricia Trouche Anne x De La Feld, Francesca

Berlioz, Philippe Zimmermann, Christian x Hélière, Arnaud x

Bonnes, Evelyne Spence, David x

Bonnet, Cécile Tighe, Adrian x

Bruno, Patrick

Caillault, Eric ASD

Cabantous, Nicolas x Breitling, Walter

Camus, Fabrice Faust, Thomas

Corselle, Bertrand Frank, Jürgen

Delettrez, Christophe x Gessler, Leo X

De Villèle, Géraud x Gotsmann, Michael

Galzin, Josette Kettner, Bernhard

Gladin, Laurent Lorenz, Jennifer

Halbout, Stéphane Lotz, Gerhard

Le Hors, Lenaic x Mattes, Christof

Levillain, Yves x Münzenmayer, Ralf X

Marchal, Bruno Piller Jörg X

Mazuray, Laurent x Purvinskis, Robert

Nonnet, Jean-Christophe x Rühe, Wolfgang

Olivier, Frederic x Slansky, Uwe X

Peden, Sylvie Holger Fischer X

Pibrac, Dominique x ASU

Reuillon, Bruno Mason, Lyn

Riguet, Nicolas

Salaün, Thierry x

Salame, Christine

Simon, Raphael

Documents

EADS ' ~ rATllOemits.sso.esa.int/emits-doc/ASTRIUMSAS/ATLID/AO... · EADS '_~ aSCrlLJm . Title . rATllO. Ref : EC.RS.ASF.ATL.00035 Issue :5 Rev. : 001 Date : 12-03-2010 Page : i