Materials and Processes Division

1
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

2

• The following section presents the requirements
  for PMP. However the actual requirements for a
  particular project depend on several factors,
  e.g.
• Type of spacecraft (manned or unmanned)
• Spacecraft orbit (LEO, GEO, polar, etc)
• Complexity (satellite, payload, etc.)
• 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

3
THE REQUIREMENTS RELATED TO MATERIALS, MECHANICAL
PARTS AND PROCESSES
4
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.

5
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).

6
European Co-operation for Space Standardisation
(ECSS) 1.

• For materials and processes the situation is
  presently as follows
• ESA PSS-01 -70 has been replaced by ECSS
  Specification ECCS-Q-70A
• 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

7
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
• 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

8
THE REQUIREMENTS

• 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.
• PLANNING AND DOCUMENTATION
• The Contractor shall ensure that the PMP
  programme is thoroughly planned and
  documented. Particular emphasis shall be placed
  on Critical PMP.
• 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.

9
THE REQUIREMENTS - Continued

• 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.

10
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.
• 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.
• 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.

11
THE REQUIREMENTS (2)

• 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.
• 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.

12
THE REQUIREMENTS (3)

• Flammability
• Products considered for use in unmanned
  spacecraft to be launched 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.
• Offgassing and Toxic analysis
• All products considered for use in the crew
  compartment of
• manned spacecraft shall be evaluated for
  offgassing and odour. Samples of each
  product shall be tested according to
  ECSS-Q-70-29.

13
THE REQUIREMENTS (3)

• 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.
• Supplementary tests
• The Contractor shall review his PMP
  programme for particular Project
  requirements and add any other test as relevant.
  These tests are subject to ESA approval.

14
MATERIAL/MECHANICAL PART ENGINEERING

• 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.
• 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.
• 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.

15
MATERIAL/MECHANICAL PART ENGINEERING (2)

• 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.

16
MATERIAL/MECHANICAL PART ENGINEERING (3)

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

17
PROCESS ENGINEERING

• 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.
• 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.

18
PROCESS ENGINEERING (2)

• 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.
• 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.

19
PROCESS ENGINEERING (3)

• 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.
• PROCESS WORKMANSHIP STANDARDS
• The Contractor shall provide detailed
  workmanship standards for processes to aid
  operators and inspectors in the establishment of
  accept/reject criteria.

20
PROCESS ENGINEERING (4)

• 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.
• NON CONFORMANCES
• Any unsatisfactory performance or non
  conformance which is observed shall be
  dispositioned in accordance with ECSS-Q-20.
• TRAINING The Contractors shall establish a
  training programme for all critical process
  operators and inspectors (e.g. PSS-01-748).

21
THE DOCUMENTATION REQUIREMENTS
22
CONTENTS OF THE DECLARED MATERIALS LIST
Materials are classified into 20 groups depending
on their type or their main use.

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

1. Adhesive tapes
2. Paints and inks
3. Lubricants
4. Potting compounds, sealants, foams
5. Reinforced plastics
6. Rubbers and elastomers
7. Thermoplastics (non adhesive tapes, foils
   (MLI),...)
8. Thermoset plastics
9. Wires and cables (for materials aspects only)
10. Miscellaneous nonmetallic materials (ceramics...)

If for a given project it is deemed necessary and
approved by ESA to create new groups, these shall
bear numbers over 20. Primers shall be classified
in the group of their associated components.
23
Example of DML
24
CONTENT of DML
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).

• COLUMN 1 Item number
• Identification 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 identification
• Trade 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.

25
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.

26
CONTENT of DML, cont

• 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

Radiation/UV/ATOX (1) R Ambiance A Temperature (2) T
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.
(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.
27
CONTENT of DML, cont

• 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 lt 1 1 1 lt 10 2 10 lt 100 3 100 lt 1000 etc.
28
CONTENT of DML, cont

• COLUMN 9
• All 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 9.1
• Outgassing (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 ).

29
CONTENT of DML, cont

• 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.

30
CONTENT of DML, cont

• 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.

31
CONTENT of DML, cont

• 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.

32
CONTENTS OF THE DECLARED PROCESS LIST
Processes are classified into 17 groups depending
on their type or their main use

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

1. Plating
2. Machining
3. Forming
4. Heat treatment
5. Special fabrication processes developed
   specifically for the programme
6. Marking
7. Miscellaneous processes
8. Inspection procedures

If for a given project it is deemed necessary to
create new groups, these shall bear numbers over
17.
33
Example of DPL
34
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 number Sequential 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
identification The correct and standard
identification of the process shall be indicated,
e.g. the process name or title bonding, coating
or soldering.
35
CONTENT of DPL, cont

• COLUMN 3 Specification
• The 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 description
• A short description of the process shall be
  entered.
• COLUMN 5 Use and location
• The 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).

36
CONTENT of DPL, cont
COLUMN 6 Manufacturers name The 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 numbers The associated
material list (DML) or mechanical parts list
(DMPL) with the process shall be entered. COLUMN
8 Criticality The 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.
37
CONTENT of DPL, cont
COLUMN 9 and 10 Justification The 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
contractors 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.
38
CONTENTS OF THE DECLARED MECHANICAL PARTS LIST
Mechanical parts are classified into 11 groups
depending on their type or their main use

• Spacing parts (e.g. washers and spacers)
• Connecting parts (e.g. bolts, nuts, rivets,
  inserts and clips)
• Bearing parts (e.g. ball-bearings and needle
  bearings)
• Separating parts (e.g. pyrotechnics, springs and
  cutters)
• Control parts (e.g. gears)
• Fluid handling parts (e.g. diffusers)
• Heating parts
• Measuring instruments (e.g. gauges and
  thermocouples)
• Optical passive equipment
• Magnetic parts
• 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)

39
Example of DMPL
40
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.
41
CONTENT of DMPL, cont

• COLUMN 1 Item number
• Sequential 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 identification
• Part 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 part
• A standard nomenclature shall be used to ensure
  correct grouping of simi-lar
• parts, 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.

42
CONTENT of DMPL, cont

• COLUMN 4 Procurement information
• A 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
  characteristics
• The 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 location
• The 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 subcontractors name shall be identified by a
  project agreed user code (6.2).

43
CONTENT of DMPL, cont
COLUMN 7 Environmental code The environmental
code is defined using
Radiation/UV/ATOX (1) R Ambiance A Temperature (2) T
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.
(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).
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CONTENT of DMPL, cont
COLUMN 8 Criticality Mechanical 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 approval The 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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CONTENT of DMPL, cont
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 contractors 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 mechanical
• part, material or process is appropriate for the
  application envisaged.
• Two issues of this are required
• Issue 0 Request accompanied by the evaluation or
  validation / qualification programme
• 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.
Strictly speaking 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
which does not meet one or more of the
specified requirements (e. g. material which
fails outgassing, is flammable, etc.). The
document includes rationale for acceptance.
This RFD would be applicable for all subsequent
items manufactured. RFW Document which asks
customer permission to use a part, material or
process where as a result of inspection etc. a
non conformance has been identified (e. g. hole
drilled in wrong place, non acceptable adhesive
used etc.). This RFW would be applicable to
this one item only.
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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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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.
51
PMP Flow chart
52
Material RFA -1
53
Material RFA -2
54
Mechanical part RFA-1
55
Mechanical part RFA-2
56
Process RFA-1
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Process RFA-2