sme initiative materials and processes division esa/estec/tos-qm sheet: 1 sme initiative course...

Materials and Processes DivisionESA/ESTEC/TOS-QM

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SME INITIATIVE COURSE MATERIALS SUMMARY PRESENTATION

Dr. Ton de Rooij

Head of Materials Mechanics and Processes Section

Materials and Processes Division

Product Assurance and Safety Department


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The following section presents the requirements for PMP. However the actual requirements for a particular project depend on several factors, e.g.

1. Type of spacecraft (manned or unmanned)2. Spacecraft orbit (LEO, GEO, polar, etc)3. Complexity (satellite, payload, etc.)4. Duration of space exposure (x years, y days, etc.)

The requirements will therefore be specified as part of the contract either in the statement of work or in the PA plan


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THE REQUIREMENTS RELATED TO MATERIALS, MECHANICAL PARTS AND PROCESSES


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PSS SpecificationsRelated to PMP

PSS‑01‑70 ‑ Issue 4 ‑ Jan 94. Material, mechanical‑part and process selection and quality control for ESA space systems and associated equipment.

This specification establishes the detailed requirements for the selection and control of materials, mechanical parts and processes for space systems and associated equipment in which the use of materials etc. with specific reliability and quality requirements is mandatory.

PSS‑01‑700‑ Issue 2 ‑ Aug 93. The technical reporting and approval procedures for materials mechanical parts and processes.

This specification provides details concerning the documentation requirements and the procedure relevant to obtaining ESA approval for the use of PMP in the fabrication of space systems associated equipment.


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ECCS Specification Related to PMP

ECSS‑Q‑70A‑April 96 Space Product Assurance ‑ Materials, Mechanical Parts and Processes.

The purpose of this standard is to define the requirements and statements applicable to Materials, Mechanical Parts and Processes to satisfy the mission performance requirements. This standard also provides details concerning the documentation requirements and the procedures relevant to obtaining approval for the use of PMP in the fabrication of Space Systems and associated equipment.

This documentation is currently under revision and issue B will include the documentation Requirements presently given in PSS‑01 ‑700.

In addition many of the lower level PSS Specification (PSS‑01‑7XX series) are being Replaced by ECCS Specification (ECSS‑Q‑70‑XX series).


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European Co‑operation for Space Standardisation (ECSS) 1.

For materials and processes the situation is presently as follows: 1. ESA PSS‑01 ‑70 has been replaced by ECSS Specification ECCS‑Q‑70A2. An additional twenty specifications, based on the PSS‑01 ‑7xx Series, have been issued a

ECSS Specifications• ECSS‑Q‑70‑02A Thermal vacuum outgassing test for the screening of space materials• ECSS‑Q‑70‑04A Thermal Cycling test for the Screening of space materials and

processes• ECSS‑Q‑70‑07A Automatic machine wave soldering• ECSS‑Q‑70‑08A The manual soldering of high reliability electrical connections• ECSS‑Q‑70‑10A Qualification of printed circuit boards• ECSS‑Q‑70‑11A Procurement of printed circuit boards• ECSS‑Q‑70‑13A The Peel and Pull Off Strength of Adhesives• ECSS‑Q‑70‑18A Preparation, assembly and mounting of RF coaxial cables• ECSS‑Q‑70‑20A Determination of the susceptibility of silver-plated copper wire and

cable to plague corrosion• ECSS‑Q‑70‑21A Flammability testing for the screening of space materials• ECSS‑Q‑70‑22A The control of limited shelf-life materials• ECSS‑Q‑70‑25A The Application of Aeroglaze 2306• ECSS‑Q‑70‑26A Crimping of high-reliability electrical connections


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European Co‑operation for Space Standardisation (ECSS) 2.

• ECSS‑Q‑70‑28A Repair and modification of PCB assemblies • ECSS‑Q‑70‑29A Offgassing Testing of Materials• ECSS‑Q‑70‑30A Wire‑wrapping of high reliability electrical connections• ECSS‑Q‑70‑33A The Application of Thermal Coating PSG120FD• ECSS‑Q‑70‑34A The Application of Aeroglaze H322• ECSS‑Q‑70‑35A The Application of Aeroglaze L300• ECSS‑Q‑70‑36A Materials selection for controlling stress corrosion• ECSS‑Q‑70‑37A Test method for stress corrosion cracking

3. An additional nine specifications are in various stages of ECSS review.• ECSS‑Q‑70B Materials, mechanical parts and processes• ECSS‑Q‑70‑01 Contamination and cleanliness control• ECSS‑Q‑70‑05 Detection of organic contamination of surfaces by IR spectroscopy • ECSS‑Q‑70‑09 Measurement of thermo-optical properties of thermal control materials• ECSS‑Q‑70‑38 High reliability soldering for surface mount and mixed technology PCBs• ECSS‑Q‑70‑46 General requirements for procurement of threaded fasteners• ECSS‑Q‑70‑50 Particulate contamination control in clean rooms by particulate fall-out

(PFO)measurements• ECSS‑Q‑70‑71 Data for selection of space materials


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THE REQUIREMENTS

1. GENERAL The Contractor shall establish and implement throughout the duration of the contract a PMP programme which ensures full compliance to PSS‑01‑70/ ECSS‑Q‑70.

2. PLANNING AND DOCUMENTATION

The Contractor shall ensure that the PMP programme is thoroughly planned and documented. Particular emphasis shall be

placed on Critical PMP.

3. PROGRAMME PLAN

The Contractor shall prepare a PMP Selection and Control Plan which describes the programme and procedures he will adopt for

compliance with the requirements of PSS‑01 ‑70/ ECSS‑Q‑70. It shall be the Contractor's responsibility to ensure that all sub‑contractors PMP programmes are consistent with his Plan. Particular attention shall be paid to specific Project requirements for PMP, their control and interfaces with sub‑contractors activities.


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THE REQUIREMENTS ‑ Continued

4. CLEANLINESS/CONTAMINATION CONTROL

The Contractor shall establish and maintain an effective contamination and cleanliness-control programme in

compliance with Project requirements according to PSS‑01‑201 (to be superceded by ECSS‑Q‑70‑01).

Cleanliness‑requirement specification (chemical and particle); Cleanliness‑control plan; Cleanliness‑monitoring procedures/methods.


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THE REQUIREMENTS (2)

PMP which cannot be considered either space proven or standard/established shall be subjected to an evaluation programme in order to assess their suitability for the intended application. This programme and subsequently its result shall be submitted to ESA.

1. Thermal Vacuum

Products considered for use in space systems shall have their outgassing properties assessed by thermal

vacuum tests according to ECSS‑Q‑70‑02.

2. Thermal Cycling

Products which are likely to be subjected to thermal stresses shall have their thermal cycling properties

assessed as per ECSS‑Q‑70‑04.


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3. Radiation

Products which will be exposed to particle/UV radiation shall be assessed to determine their ability to withstand the type and degree of radiation dosage expected during the mission. Tests are specified in PSS‑01‑706.

4. Stress Corrosion

Products intended for structural applications and likely to be exposed to long term terrestrial storage, or flown on the STS, or used in launchers shall possess a high resistance to SCC. Structural products of a metallic nature shall be selected from the preferred list in Table 1 of ECSS‑Q‑70‑36. Where no data exists testing shall be performed as per ECCS‑Q‑70‑37.


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5. Flammability

Products considered for use in unmanned spacecraft to belaunched by the STS and manned spacecraft (including

those of the spacecraft itself, stored equipment or payload/experiments) shall be evaluated for

flammability resistance in the most hazardous environment Flammability testing is described in ECSS-Q-70-21.

6. Offgassing and Toxic analysis

All products considered for use in the crew compartment of

manned spacecraft shall be evaluated for offgassing andodour. Samples of each product shall be tested according to

ECSS‑Q‑70‑29.


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7. Atomic Oxygen

All products considered for use on the external surface of spacecraft intended for low‑orbit operations shall be

evaluated for their resistance to atomic oxygen erosion. Proposed tests shall be subject to ESA approval.

8. Supplementary tests

The Contractor shall review his PMP programme for particularProject requirements and add any other test as relevant.

These tests are subject to ESA approval.


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MATERIAL/MECHANICAL PART ENGINEERING

1. SELECTION The Contractor shall be responsible for the selection and for demonstrating that they are capable of meeting the operating, environmental, physical, chemical, safety, quality and reliability conditions defined in the relevant specifications and in the contract.

2. SELECTION OF SPACE‑PROVEN MATERIALS

Well known materials/mechanical parts for which test data applicable to the space environment are available or which have been previously used in space, or similar, applications shall be selected wherever possible. However each material/mechanical part and its applications for a given Project shall be considered separately.

3. SELECTION OF OTHER MATERIALS

Request for approval (RFAs) of material/mechanical parts which do not meet the requirements of 2) above shall be submitted to ESA. The format and content of the RFA is given in PSS‑01 ‑700. This can be modified by a Project (subject to approval) if the specific requirements of the Project make this necessary.


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MATERIAL/MECHANICAL PART ENGINEERING (2)

4. DECLARED MATERIAL LIST (DML)/DECLARED MECHANICAL PARTS LISTS (DMPL)

The Contractor shall establish a consolidated DML and DMPL of all items used in the system.

Notes: The project may decide not to consolidate the lists but to compile an assembly of Lists per Configuration item.

The Project may decide not to require a separate DMPL. In this case the items are added to the DML;

The format and content of the DML/DMPL is given in PSS‑01‑700 (ECSS-Q-70B). This can be modified by a Project (subject to approval) if the specific requirements of the Project make this necessary.

Amendments to the DML/DMPL shall only be implemented through established change procedures.


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MATERIAL/MECHANICAL PART ENGINEERING (3)

5. SPECIFICATIONS/STANDARDS

Each type of material/mechanical part used by the Contractor and listed in the DML/DMPL shall be covered by a specification or standard.

6. NON‑CONFORMANCES

Non‑conforming materials/mechanical parts found during incoming inspections, assembly or test shall be dispositioned in accordance with ECSS‑Q‑20.


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PROCESS ENGINEERING

1. SELECTION The Contractor shall be responsible for the selection of processes and for demonstrating that they are capable of meeting the

requirements as defined in the applicable Specifications and in the contract. The Contractor and sub‑contractor shall plan and enforce an effective process control programme. ESA reserves the right to audit critical processing lines.

2. STANDARD/ESTABLISHED PROCESSES

Standard processes shall be selected whatever possible. Critical processes, unless performed in accordance with

PSS‑01 ‑7XX/ECSS‑Q70‑XX series documents shall require further identification and approval before use.


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PROCESS ENGINEERING (2)

3. NONASSESSED PROCESSES

RFAs for processes for which there is no known previous history shall be fully justified and be subjected to an evaluation programme. The process identification and approval documents, defined in PSS‑01 ‑700, shall be submitted to ESA.

4. DECLARED PROCESSES LIST (DPL)

The Contractor shall establish a DPL of all processes used in the programme. The format and content of such a DPL is given

in PSS‑01 700. Amendments to the DPL shall be implemented only through established change procedure.


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5. PROCESS SPECIFICATION/STANDARD

Each process shall be covered by a process specification or standard. Maximum use shall be made of existing ESA Specifications/standards and ESA approved Specifications/standards produced by international organisations and nations agencies.

6. PROCESS WORKMANSHIP STANDARDS

The Contractor shall provide detailed workmanship standards for processes to aid operators and inspectors in the

establishment of accept/reject criteria.


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7. CRITICAL PROCESSES

Critical Processes shall be subject to stringent controls in form of documentation, QA supervision (MIP, KIPs etc). and final inspection/test. Critical processes shall be defined by the Contractor in the early phase of the contract.

8. NON CONFORMANCES

Any unsatisfactory performance or non conformance which is observed shall be dispositioned in accordance with ECSS‑Q‑20.

9. TRAINING The Contractors shall establish a training programme for all critical process operators and inspectors (e.g. PSS‑01‑748).


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THE DOCUMENTATION REQUIREMENTS


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CONTENTS OF THE DECLARED MATERIALS LIST

1. Aluminium and aluminium alloys

2. Copper and copper alloys

3. Nickel and nickel alloys

4. Titanium and titanium alloys

5. Steels

6. Stainless steels

7. Filler metals : welding, brazing, soldering

8. Miscellaneous metallic materials

9. Optical materials

10. Adhesives, coatings, varnishes

11. Adhesive tapes12. Paints and inks13. Lubricants14. Potting compounds, sealants, foams15. Reinforced plastics16. Rubbers and elastomers17. Thermoplastics (non adhesive tapes,

foils (MLI),...)18. Thermoset plastics19. Wires and cables (for materials aspects

only)20. Miscellaneous nonmetallic materials

(ceramics...)

Materials are classified into 20 groups depending on their type or their main use.

If for a given project it is deemed necessary and approved by ESA to create newgroups, these shall bear numbers over 20.Primers shall be classified in the group of their associated components.


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Example of DML


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CONTENT of DML

COLUMN 1: Item numberIdentification number in each group. One only per material type. Does not change during the life of the materials list (sub‑items permitted when deemed necessary).

COLUMN 2: Commercial identificationTrade name and number (to be completed in full) e.g. “ARALDITE AV 100". Correct and standard designation.ESA has chosen:• Trade name + number. For example, "ARALDITE AY 105"• If no trade name exists, then the manufacturer's name plus number are entered; e.g. "SCHOTT BK7“• In the case of metal alloys, the AA system is recommended for aluminium alloys, and the

AISI system for steels ; for other metals or alloys, the main constituent will be entered first except in the case of a traditional name (e.g. brass or bronze).

For each material as designated above, a unique item number shall be given. If several lines are used for different applications and/or processing, sub‑item numbers shall be added.

The materials list consists of 10 columns which shall be completed as indicated below. Furthermore, similar materials shall be grouped together as specified above. If a particular item does not apply, write N.A. (Not Applicable).


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CONTENT of DML, cont…

COLUMN 3: Chemical nature and type of product

Example: epoxy resin, polyurethane adhesive, or Ti6AI4V alloy.

COLUMN 4: Procurement information

Manufacturer/supplier: name of the manufacturer and name of the supplier if different.

Specification: reference of the procurement specification with, if considered useful, issue and revision. It may be replaced by a national specification number if this exists and makes source of procurement irrelevant.

COLUMN 5: Processing parameters (summary):

Give as relevant: mixture proportions, cure temperature, special cleaning agent, surface treatment, thermal treatment, temperature, etc..

NOTE: Specification number is required, but not sufficient for ESA purposes.


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COLUMN 6: Use and location

Indicate in what subsystems, box or item the material is used and whether it acts as structural element, thermal control, electrical insulation etc. as relevant.

COLUMN 7: Environmental code

G = Geostationnary

L = Low orbit

B = Radiation belts

I = Interplanetary

S = outside shadow

L = outside light

V = Vacuum

H = Hermetic

M = Manned

E = Elevated pressure

1 = 0 to 100 K

2 = 101 to 200 K

3 = 201 to 300 K

"

etc.

Radiation/UV/ATOX (1) R Ambiance A Temperature (2) T

(1) For materials inside the spacecraft, choose a letter from the left‑hand column. For materials on the surface of the spacecraft, combine this letter with "L" or "S".

(2) Thermal cycling to be indicated by two values, e.g. 3/5.(3) "RT" can be accepted as a code between 283 K (10° C) and 313 K (40° C).Materials which are at a boundary between environments shall be described by two sets of odes.


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COLUMN 8: Size code

Choose an alphanumeric combination from the above mentioned table, e.g. A5 or V2 or W3.

AREA

VOLUME

MASS

A (cm2)

V (cm3)

W (g)

0 = 0 < 1

1 = 1 < 10

2 = 10 < 100

3 = 100 < 1000

etc.


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COLUMN 9All the codes of Column 9 shall be relevant for the project concerned, which implies that they refer to validated data applicable to this project (not too old, same processing, same composition, QC tests run on the same procured lot, etc.) .Reference of test report and relevant test result code to be given in Subcolumn 9.1. SUBCOLUMN 9.1Outgassing (OUT):P‑ The material passed the outgassing test detailed in ECSS-Q-70-02 .

Reference of test report to be given in Subcolumn 9.2.F‑ The material failed . Waiver reference in Subcolumn 9.2.U‑ Materials of which outgassing characteristics are unknown.

Stress Corrosion Cracking (SCC):A‑ The material is known to have a high resistance to SCC. Table I document ECSS-Q-70-36 B‑ Table II and III document ECSS-Q-70-36.

Justification for approval (test reference) stated in Subcolumn 9.2 (generally making reference to ECSS-Q-70-36).U‑ Materials and / or weldments for which SCC characteristics are unknown. An SCC evaluation form is required, based if necessary on tests (see ECSS-Q-70-37 ).


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Corrosion (Corr.)

A‑ The material does not require a surface treatment or coating for its intended application, otherwise it shall be rated B.

B‑ Details of the surface treatment to be given in Column 5.

Flammability (Flamm.) (if applicable):

P‑ The material passed the requirements of document ESA PSS‑01 ‑721.

F‑ The material failed the test of document ESA PSS‑01 ‑721 in the applicable atmosphere. Waiver reference in Subcolumn 9.2.

U‑ Materials of which characteristics are unknown.

Offgassing (OFF) (if applicable):

P‑ The material passed the requirements of document ESA PSS‑01 ‑729.

F‑ The material failed : waiver reference in Subcolumn 9.2

U‑ Materials of which offgassing characteristics are unknown.


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SUBCOLUMN 9.2: Justification for approval

The purpose of this Subcolumn is to enter any additional information that may be necessary in order to achieve customer approval. This information is reference of the Requests For Approval, reference of justificatory file for materials approved for other space or aeronautical programmes meeting the specific needs of the programme, reference of the evaluation report or waivers etc.. These documents must be made available to ESA on request.


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SUBCOLUMN 9.3: Approval status of the Contractor

A: Approved ‑ All Materials classified A may be used without restriction.

Y: Approved with restriction ‑ These materials require the preparation of QC test specimens or a treatment before use: potting, coating, test specimens...

W: Approved with a waiver ‑ These materials do not meet the requirements but are used for functional reasons. The use of such materials shall be reduced to a minimum. All the waivers shall be approved by ESA. The waiver number shall be entered in Subcolumn 9.2.

P: Pending a decision ‑ Materials for which an evaluation report or a waiver is awaiting the Contractor's provisional or definitive approval.

O: Open ‑ New materials or materials for which investigations and qualification are in progress.

D: Deleted ‑ This classification is used for a material which is no longer used .

COLUMN 10: ESA approval and comments

This column will be completed by ESA in accordance with the standard

comments listed in Annex E.


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CONTENTS OF THE DECLARED PROCESS LIST

1. Adhesive bonding

2. Composite manufacture

3. Encapsulation/moulding

4. Painting/coating

5. Cleaning

6. Welding/brazing

7. Crimping/stripping/wire wrapping

8. Soldering

9. Surface conversion treatments

10. Plating

11. Machining

12. Forming

13. Heat treatment

14. Special fabrication: processes developed specifically for the programme

15. Marking

16. Miscellaneous processes

17. Inspection procedures

If for a given project it is deemed necessary to create new groups, these shall bear numbers over 17.

Processes are classified into 17 groups depending on their type or their main use


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Example of DPL


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CONTENT of DPL

The header information identifies the list as the declared materials list and includes the issue number and date of issue. It includes the relevant CI number (configuration item number as per project definition) if required by the business agreement. The materials group number may also be included here.

COLUMN 1: Item numberSequential item number in each group of the declared process list. One only per process type. Does not change during the life of the process list.

COLUMN 2: Process identificationThe correct and standard identification of the process shall be indicated, e.g. the process name or title: bonding, coating or soldering.


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CONTENT of DPL, cont…

COLUMN 3: SpecificationThe name or abbreviation of the one who applies the process shall be identified.A reference shall be made to the associated procedure, e.g. national, international, EN, ISO, ECSS or company in house together with the issue, revision and date.

COLUMN 4: Process descriptionA short description of the process shall be entered.

COLUMN 5: Use and locationThe codes entered shall define the location of the process with respect to the:

• subsystem,• particular piece of equipment (box or item),• location within the equipment, and• use of the equipment (e.g. a structural element, thermal control, electrical insulation).


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COLUMN 6: Manufacturer’s nameThe name or abbreviation of the one who applies the process shall be identified by a project agreed user code if different to that entered in column 3.

COLUMN 7: Associated item numbersThe associated material list (DML) or mechanical parts list (DMPL) with the process shall be entered.

COLUMN 8: CriticalityThe criticality shall be considered either as critical “C” or non-critical “N”.If a process is considered critical references to the relevant RFA shall be entered.


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COLUMN 9 and 10: JustificationThe purpose of the justification and approval fields shall be to enter any additional information that can be necessary to obtain customer approval. Supporting references for the justification shall be made available if re-quested. The supplier and customer approval status code shall be selected from:

A Approved – All processes classified “A” may be used without restriction.X Approved with a RFA – These processes shall be subjected to an evaluation or validation programme. The RFA number shall be entered as a comment.W Approved with a waiver – These processes do not meet the requirements but are used for functional reasons. The use of such processes shall be reduced to a minimum. All deviation requests shall be approved by the customer. The waiver number shall be entered as a comment.P Pending a decision – Mechanical parts for which an evaluation report or a waiver is waiting for the contractor’s provisional or definitive approval.O Open – New processes or processes for which investigations and qualifications are in progress.R Rejected.D Deleted – This classification is used for a process which is no longer used.

Comments shall be entered wherever approval cannot be given.


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CONTENTS OF THE DECLARED MECHANICAL PARTS LIST

51. Spacing parts (e.g. washers and spacers)52. Connecting parts (e.g. bolts, nuts, rivets, inserts and clips)53. Bearing parts (e.g. ball-bearings and needle bearings)54. Separating parts (e.g. pyrotechnics, springs and cutters)55. Control parts (e.g. gears)56. Fluid handling parts (e.g. diffusers)57. Heating parts58. Measuring instruments (e.g. gauges and thermocouples)59. Optical passive equipment60. Magnetic parts61. Other parts

If for a given project it is deemed necessary to create new groups, these shall bear numbers over 61.

Items which should appear in the EEE parts list should not be repeated here (e.g. heaters, some valves, thermostats, relays, transformers coils, solenoids and ferrite cores)

Mechanical parts are classified into 11 groups depending on their type or their main use


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Example of DMPL


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CONTENT of DMPL, cont…

This refers to the information which shall be included in the DMPL The header information identifies the list as the declared materials list and includes the issue number and date of issue. It includes the relevant CI number (configuration item number as per project definition) if required by the business agreement. The materials group number may also be included here.


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COLUMN 1: Item numberSequential itemnumber in each group of the list. One only per mechanical part type. Does not change during the life of the mechanical parts list.

COLUMN 2: Commercial identificationPart number and material of construction. Where complex items involving many materials are used then reference shall be given to a document where the relevant materials are listed. This document may be included as an annex to the DMPL or shall be available for inspection if requested.

COLUMN 3: Type of partA standard nomenclature shall be used to ensure correct grouping of simi-larparts, e.g.:

• valve, one way (and not “one-way valve”)• valve, two way (and not “two-way valve”).

Surface treatment should be described if applicable.


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COLUMN 4: Procurement informationA short designator “M” or “D” shall be entered to indicate if the mechanical part is procured from a manufacturer or distributor.Manufacturer or supplier: name of the manufacturer and name of the supplier if different.Procurement specification: reference of the procurement specification with, if considered useful, issue, revision and date. It may be replaced by a national or international specification if this exists and identifies the source of procurement if relevant.

COLUMN 5: Elementary function, main characteristicsThe function of the mechanical part shall be entered.The main characteristics of the mechanical part shall be entered, e.g. number of revolutions per minute for a ball bearing.

COLUMN 6: Use and locationThe codes entered (6.1) shall define the location of the mechanical part with respect to the:

• subsystem,• particular piece of equipment (box or item),• location within the equipment, and• use of the equipment.

The subcontractor’s name shall be identified by a project agreed user code (6.2).


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G = Geostationnary

L = Low orbit

B = Radiation belts

I = Interplanetary

S = outside shadow

L = outside light

V = Vacuum

H = Hermetic

M = Manned

E = Elevated pressure

1 = 0 to 100 K

2 = 101 to 200 K

3 = 201 to 300 K

"

etc.

Radiation/UV/ATOX (1) R Ambiance A Temperature (2) T

(1) For materials inside the spacecraft, choose a letter from the left‑hand column. For materials on the surface of the spacecraft, combine this letter with "L" or "S".

(2) Thermal cycling to be indicated by two values, e.g. 3/5.(3) "RT" can be accepted as a code between 283 K (10° C) and 313 K (40° C).

COLUMN 7: Environmental codeThe environmental code is defined using:


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COLUMN 8: CriticalityMechanical parts shall be considered either as critical “C” or non-critical “N”. If a mechanical part is considered critical the reason for the criticality and methods of control shall be entered.

COLUMN 9: Supplier justification and approvalThe purpose of the supplier justification and approval fields shall be to enter any additional information that can be necessary in order to achieve customer approval. This information comprises reference and issue of the RFA or approval, mechanical parts justification file, evaluation reports and deviation requests. These documents shall be made available to the final customer on request. In order to justify the use of a mechanical part, reference shall be given to the relevant test data that demonstrate acceptability of the mechanical part under the environment conditions and the application relevant to the particular project concerned. Standard abbreviations shall be used to summarize the acceptance status of a mechanical part for a particular property. These shall be defined by the customer.The supplier approval status code shall be selected from the next table.

COLUMN 10: The customer approval status code shall be selected from the table.Additional comments shall be included where appropriate.


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Approval status: Code Description

A Approved – All mechanical parts classified “A” may be used without restriction.X Approved with a RFA – These mechanical parts shall be subjected to an evaluation

or validation programme. The RFA number shall be entered as a comment.W Approved with a waiver – These mechanical parts do not meet the requirements but

are used for functional reasons. The use of such mechanical parts shall be reduced to a minimum. All deviation requests shall be approved by the customer. The waiver number shall be entered as a comment.

P Pending a decision – Mechanical parts for which an evaluation report or a waiver is waiting for the contractor’s provisional or definitive approval.

O Open – New mechanical parts or mechanical parts for which investigations and qualifications are in progress.R Rejected.D Deleted – This classification is used for a mechanical part which is no longer used.

Comments shall be entered wherever approval cannot be given.


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The Request for Approval(RFA)

This is a document with which the user asks the customer for permission to use a critical mechanical part, material or process.

The information given shall make possible to judge whether the critical mechanicalpart, material or process is appropriate for the application envisaged.

Two issues of this are required:

1. Issue 0: Request accompanied by the evaluation or validation / qualification programme;

2. Issue 1: Request accompanied by the validation or qualification results.

(Definition from ECSS- Q- 70B Draft)


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The RFA (cont…)

For critical PMP the supplier shall submit an RFA, suitable formats are given in PSS- 01- 700 and ECSS- Q- 70B (Draft).

The initial issue (Issue 0) of the RFA for provisional approval should be provided as early as possible and not later than PDR. This approval gives agreement to perform the evaluation / validation / qualification programmes and allows the PMP to be included in the design process. Definitive approval is only given after successful completion of the relevant test programme; at which time the RFA is updated with the relevant test report references etc and reissued (Issue 1) in its final form. This should be complete prior to CDR such that the material can be used in flight hardware construction.


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Request for Approval (RFA)Request for Deviation (RFD)

Request for Waiver (RFA)

There is, unfortunately, much confusion surrounding the use of the above terms. Strictlyspeaking they should be used as follows:

RFA: Document which asks customer permission to use a critical part, material or process.

RFD: Document which asks customer permission to use a part, material or process whichdoes not meet one or more of the specified requirements (e. g. material which failsoutgassing, is flammable, etc.). The document includes rationale for acceptance. ThisRFD would be applicable for all subsequent items manufactured.

RFW: Document which asks customer permission to use a part, material or process where asa result of inspection etc. a non conformance has been identified (e. g. hole drilled inwrong place, non acceptable adhesive used etc.). This RFW would be applicable to thisone item only.


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SME Initiative

RFA - RFD - RFA

• European companies and ESA are more used to using the term RFW to cover both RFD and RFW. The RFD is called up in ECSS documentation (not consistently) and it is not uncommon to find a statement of work where, for example, ECSS- Q- 70A is a requirements document, that a specific change from the use of the term RFD to RFW is included.

• On manned space projects, the term RFA is used in place of the RFD / RFW to give a rationale for approval for safety critical materials and mechanical parts (equivalent to the NASA materials usage agreement, MUA). One added complication is that the format of the RFA is different to that given in either PSS- 01- 700 or ECSS- Q- 70B (draft) and the two should not be confused.


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SME Initiative

RFA for Materials Certification

As mentioned earlier on manned space programmes on RFA is used to justify the use of materials / mechanical parts which do not meet the materials requirements related to specify (flammability, offgassing and stress corrosion). Some examples of completed RFAs are attached.


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PMP Flow chart


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Material RFA -1


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Material RFA -2


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Mechanical part RFA-1


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Mechanical part RFA-2


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Process RFA-1


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Process RFA-2

sme initiative materials and processes division esa/estec/tos-qm sheet: 1 sme initiative course...

Documents

processes ecss q

ecss specifications

pmp ecss q

pfomeasurements ecss

eccs specification ecss

ecss specification eccs

cleanliness control

stress corrosion ecss