SCIENCE SPACECRAFT STRUCTURE REQUIREMENT …emits.sso.esa.int/emits-doc/ASTRIUMLIM/LISA_SCIENCE_STRUCTURE… · S2.ASU.RS.2006 Issue 1 Page 6 of 42 ... Materials Selection for Controlling

~

LlSA Pathfinder IUM

SCIENCE SPACECRAFT STRUCTURE REQUIREMENT S P EC I F IC AT10 N

S2 ASU RS 2006 Issue 1

Page 1 of 42

CI CODE: 1242110 DRL Refs : N/A

UK EXPORT CONTROL RATING : 9E001 Rated By : K. Tomkins

Prepared by:

Checked by:

Approved by:

Authorised by:

A -4.1 Date: I 7 [.y/ g j - .~~~~~ .., ......... ........................... ~.~~~~ .........

N. Donbar/ K. Tomkins

This document is produced under ESA contract, ESA export exemptions may therefore apply. These Technologies may require an export licence if exported from the €U

OR This document is exported under UK Export Licence reference:- e.g. Canada quote CGEA EUOOl

These technologies may require an export licence if exported to countries not covered by this IicenceESA export licence exception applies, reference HM Customs Tariff Vol 1 Part 4 Para 4.3.1 1

0 EADS Astrium Limited 2005

€ADS Astrium Ltd owns the copyright of this dowment which is supplied in confidence and which shall not be used for any purpose other than that for which it is supplied and shall not in whole or in part be reproduced, copied, or

communicated to any person without written permission from the owner.

EADS Astrium Limited, Registered in England and Wales No. 2449259 Registered Office: Gunnels Wood Road, Stevenage, Hertfordshire, SGI 2AS, England

DOCument Autogenerated from DOORS Module : LlSA PathfinderlLevel YMechanicaUSCWSCM Structure Sdence Spacecrafi Structure - Requirement Specification Issue 1 .dm

WILSON_R

WILSON_R

WILSON_R

LISA Pathfinder

S2.ASU.RS.2006Issue 1

Page 2 of 42

EADS Astrium Ltd owns the copyright of this document which is supplied in confidence and which shall not be used for any purpose other than that for which it is supplied and shall not in whole or in part be reproduced, copied, or communicated to any person without written permission from the owner.

S2.ASU.RS.2006 Issue 1.doc

INTENTIONALLY BLANK

LISA Pathfinder


Page 3 of 42



CONTENTS

1. INTRODUCTION AND SCOPE.....................................................................................................................6 1.1 Introduction.............................................................................................................................................6 1.2 Requirement Definition...........................................................................................................................6

2. APPLICABLE AND REFERENCE DOCUMENTS ........................................................................................7 2.1 Applicable Documents............................................................................................................................7 2.2 Standards ...............................................................................................................................................7 2.3 Abbreviations..........................................................................................................................................7

3. FUNCTIONAL REQUIREMENTS..................................................................................................................8 3.1 System Requirement ..............................................................................................................................8

3.1.1 Satellite Design ............................................................................................................................9 3.1.2 Reference Frames........................................................................................................................9 3.1.3 Mission Phases ..........................................................................................................................10 3.1.4 Structure Configuration ..............................................................................................................10 3.1.5 Mass...........................................................................................................................................17

3.2 Interface Requirements ........................................................................................................................18 3.2.1 LTP Interfaces ............................................................................................................................18 3.2.2 Separation System Interfaces ....................................................................................................18

3.3 Mechanical Design Requirements........................................................................................................18 3.3.1 Functional Requirements ...........................................................................................................18 3.3.2 Performance Requirements .......................................................................................................19

3.4 Electromagnetic Compatibility ..............................................................................................................19 3.5 MGSE Requirements............................................................................................................................19

4. GENERAL DESIGN AND INTERFACE REQUIREMENTS ........................................................................25 4.1 Product Assurance ...............................................................................................................................25 4.2 General Design Requirements .............................................................................................................25

4.2.1 Design Safety .............................................................................................................................25 4.2.2 Venting .......................................................................................................................................25 4.2.3 Identification & Marking..............................................................................................................25 4.2.4 Transportation, Handling and Storage .......................................................................................25 4.2.5 Parts Material and Processes ....................................................................................................26

4.3 Mechanical Design and Interface Requirements .................................................................................26 4.3.1 Structural Design........................................................................................................................26 4.3.2 Design Requirements.................................................................................................................29 4.3.3 Mechanical Mathematical Model Requirements ........................................................................30

5. ENVIRONMENT DESIGN REQUIREMENTS .............................................................................................31 5.1 Atmospheric Conditions .......................................................................................................................31

5.1.1 Cleanliness.................................................................................................................................31 5.2 Mechanical Environment ......................................................................................................................31

5.2.1 Ground Environment ..................................................................................................................31 5.2.2 Launch Environment ..................................................................................................................32 5.2.3 Flight Environment .....................................................................................................................33 5.2.4 Mechanical Testing ....................................................................................................................33

5.3 Thermal Environment ...........................................................................................................................34

6. GDIR APPLICABILITY MATRIX..................................................................................................................35

LISA Pathfinder


Page 4 of 42



TABLES Table 3.1-1: SCM & LCM Reference Frames .................................................................................................10 Table 3.1-2: Flight Structural Items .................................................................................................................12 Table 3.1-3: Dummy Structural Items..............................................................................................................13 Table 3.1-4: AIV Handling Cases ....................................................................................................................14 Table 3.1-5: AOCS Unit Alignment Requirements ..........................................................................................16 Table 3.1-6: Connector Brackets.....................................................................................................................17 Table 4.3-1: Design Safety Factors .................................................................................................................28 Table 4.3-2: Additional Safety Factors ............................................................................................................29 Table 5.2-1: Ground Loads..............................................................................................................................31 Table 5.2-2: AIV Handling Accelerations.........................................................................................................31 Table 5.2-3: Flight Limit Loads ........................................................................................................................32

FIGURES Figure 3.1-1 : LISA Pathfinder Launch Composite............................................................................................9 Figure 3.1-2: SCM & LCM Reference Frames ................................................................................................10 Figure 3.1-3: Exploded View Of Structure.......................................................................................................11 Figure 3.5-1: Integration Configuration: SCM Hoisting....................................................................................21 Figure 3.5-2: Integration Configuration: SCM Mounted via Clampband at Separation Plane.........................21 Figure 3.5-3: Integration Configuration: SCM Inverted Mounting....................................................................22 Figure 3.5-4: Integration Configuration: SCM +PRM Hoisting ........................................................................22 Figure 4.3-1: Load Factor Philosophy for Definition of Design Loads.............................................................27

LISA Pathfinder


Page 5 of 42



INTENTIONALLY BLANK

LISA Pathfinder


Page 6 of 42



1. INTRODUCTION AND SCOPE

1.1 Introduction LISA Pathfinder is the second of the Small Missions for Advanced Research and Technology (SMART-2), an element of the European Space Agency's “Cosmic Vision” plan for scientific projects. The purpose of the LISA Pathfinder mission is to flight test key technologies critical for the future space cornerstone mission LISA. Among these technologies, the demonstrations of the LISA Technology Package (LTP) and the µPropulsion Technologies have been identified as mandatory. Additionally the mission will enable the in-flight demonstration of the NASA provided DRS (Disturbance Reduction System). The LISA Pathfinder spacecraft, to be launched in TBD, will demonstrate both electric and cold gas micro-thrusters during its 1 year mission. This document defines the mission, performances, environment, interface and design requirements for the Science Spacecraft Structure subsystem for the LISA Pathfinder demonstration payload.

This document gathers together all the contractually relevant requirements and constraints for the LISA Pathfinder Science Spacecraft (SCM) Structure and its supporting elements. This issue of the specification includes: � the performance as well as design and interface requirements of subject hardware; Future issues of the specification will include references to � the product assurance requirements; � the testing and verification requirements.

1.2 Requirement Definition Requirements within this document are shown in an italic font. Information within this document is shown in normal font. Each requirements is preceded by a summary line that contains the following fields, delimited by "/".

� <Doors Requirement Number> SCM-xyz. This is a unique number, assigned consecutively

� <Created From> Shows parent requirement

� <Test Method> T= Test, A = Analysis, I = Inspection, R = Review of Design

Requirement Text - If tables are considered as part of requirement they are referenced clearly in the text and inserted after and separated from the requirement table and are managed as free text attached to the identifier requirement.

Upper Links - The trace to the upper level requirements shall be managed with the following format:

� AAA-NNNN where AAA is a label associated to the upper document and NNNN the requirement identifier of this upper level.

� Or CREATED key word if the requirement has no link with upper level

All document elements, which are not presented in the format explained above are not requirements and will not be verified or tracked.

In references to GDIR requirements the section number is provided for information only. If there is any conflict between the GDIR requirement number and the section number then the requirement number takes precedence.

LISA Pathfinder


Page 7 of 42



2. APPLICABLE AND REFERENCE DOCUMENTS

2.1 Applicable Documents The Applicable Documents are listed below, and are referenced in the text with the acronym AD-x.

AD-1 General Design & Interface Requirements S2.ASU.RS.2031

AD-2 Product Assurance Requirements For Subcontractors S2.ASU.RS.1005

AD-3 Science Spacecraft Mechanical Interface Control Document S2.ASU.ICD.2002

AD-4 Mass Distribution for SCM Structure Design S2.ASU.TN.0067

AD-5 Thermal Mapping Cases for SCM Thermoelastic & Structural Design S2.ASU.TN.0068

AD-6 Solar Array (Top Floor) Interface Requirements TBD

The issue valid at contract signiture applies.

2.2 Standards The Standards are listed below, and are referenced in the text with the acronym STD-x.

STD-3 Space Engineering - MechanicalECSS-E-30 Parts 1A to 8A STD-14 Space Product Assurance - Materials Selection for Controlling Stress Corrosion Cracking ECSS-Q-70-36. STD-16 Space Engineering - Verification ECSS-E-10-02A STD-17 Space Engineering - Testing ECSS-E-10-03A STD-18 Metallic Materials & Elements For Aerospace Vehicle Structure MIL-HDBK-5H STD-19 Structural Materials Handbook PSS-03-203 Volumes 1 & 2 STD-20 Composite Materials Handbook MIL-HDBK-17 STD-21 Space Engineering - Fracture Control ECSS-E-30-01A

2.3 Abbreviations Abbreviations and acronyms are contained in:- Acronyms, Abbreviations & Terminology S2.ASU.LI.1006

LISA Pathfinder


Page 8 of 42



3. FUNCTIONAL REQUIREMENTS

3.1 System Requirement The system requirements for the SCM Structure require a design solution that minimises the gravitational influence of the structure on the two payloads in the Central Cylinder. The physical movement of the structure mass has to be minimised, therefore, driving the design towards materials that combine high stiffness and strength with low distortion characteristics. To this end, the expected design solution is expected to be a CFRP structure.

The SCM Structure design shall therefore minimise the following distortion effects:- � 1g-0g transition � Structural Hysteresis � CFRP moisture loss � CFRP outgassing shrinkage � launch settling � thermoelastic distortion

SCM-57/SRS-457;RD-71/A Thermal distortion of the SCM Structure shall be minimised by the use of quasi-isotropic laminate lay-up to achieve a coefficient of thermal expansion of less than 0.27 x 10-6 /�.

SCM-1124/RD-71/T,A The structure subsystem shall be designed so that deformations between identified points on the structure do not deform beyond a certain magnitude when the structure is subjected to a global temperature of 30oC different to the nominal temperature. The measurement points are as follows:-

SCM-1125/RD-71/T,A Between any two LTP interface points:, the deformation shall not exceed:- In X-direction: 1.33 x 10-6m (interfaces on the same panel, only), In Y-direction: 4.42 x 10-6m (displacement between panels) In Z-direction: 2.91 x 10-6m (interfaces on the same panel, only).

SCM-1126/RD-71/T,A Between a fixed datum point on the structure (on CFRP part of central cylinder adjacent to interface ring) and the identified points, the deformation shall not exceed:- All thrusters: Radially from S/C centreline (Z-axis): 7.3 x 10-6m In S/C Z-direction: 3.0 x 10-6m LTP: Radially from S/C centreline (Z-axis): 2.5 x 10-6m In S/C Z-direction: 7.0 x 10-6m Any Shear or Closure Panel edge:- Radially from S/C centreline (Z-axis): 9.55 x 10-6m In S/C Z-direction: 6.0 x 10-6m

SCM-1127/RD-71/T Material properties and thermal distortions shall be demonstrated by tests at appropriate level. The thermal distortions shall be demonstrated with the fully integrated structure suspended to simulate free-free boundary conditions and normal atmospheric conditions (apart from temperature)

SCM-58/SRS-457;RD-71/T,A Moisture loss of the SCM Structure shall be minimised by the use of materials with low moisture loss, such as CFRP/cyanate ester system or other second generation combination, to achieve Total Mass Loss of less than 0.3% by weight of non-metallic panels and a free strain of less than 8.7 x 10-6.

LISA Pathfinder


Page 9 of 42



Note : The normal rationale that TML is largely water will not be a justifiable reason for acceptance on LISA Pathfinder due to the science requirement of the mission.

SCM-490/SRS-457;RD-71/A Structural distortions due to all effects shall be identified and quantified at all critical interfaces.

3.1.1 Satellite Design At launch, LISA Pathfinder Launch Composite (LCM) consists of two elements, the Science Spacecraft (SCM) and the Propulsion Module (PRM), the configuration of which is shown illustratively in Figure 3.1-1.

SCM

PRM

LCM

Figure 3.1-1 : LISA Pathfinder Launch Composite The SCM is mounted on top of the PRM and secured by a low shock separation system, which allows the PRM to be detached once the operational orbit around the L1 Lagrange point has been reached.

At the core of the SCM Structure is a carbon fibre honeycomb Central Cylinder, inside which the sensor assemblies of the two experiments are mounted. The two experiments are the LISA Technology Package (LTP) and the Disturbance Reduction System (DRS). The LTP Core Assembly (LCA) is mounted in the upper part of the cylinder between two parallel Shear Walls each with an orthogonal Support Wall. The DRS Sensor Assembly is mounted in the lower part of the cylinder on the underside of a circular Panel (referred to as the DRS Base Plate).

Radially surrounding the Central Cylinder are eight equipment bays separated by carbon fibre honeycomb Shear Walls, onto which are mounted all elements not requiring direct visibility of the external environment.

Each of the equipment bays are enclosed by a carbon fibre honeycomb External Wall, onto which are mounted any element requiring direct visibility of the external environment.

Finally further carbon fibre honeycomb panels form the Top Floor (a single piece onto which the solar array is bonded and a number of Digital Sun Sensors (DSS) are mounted), and the Lower Floor (three pieces).

3.1.2 Reference Frames SCM-75/SRS-858, SRS-860/R

The SCM design shall adopt the axis systems defined in Table 3.1-1 which is depicted in AD-3.

LISA Pathfinder


Page 10 of 42



SCM-76/SRS-858/R The X_ss_mf and Y_ss_mf shall be clearly marked on the SCM I/F Ring.

NAME DESCRIPTION LOCATION

O_ss_mF Science Spacecraft Principal Reference Frame

Centre of Science Spacecraft / Propulsion Module Separation Plane.

O_ss_aF Science Spacecraft Alignment Frame Centre of the principle Science Spacecraft alignment cube.

O_lc_mF Launch Composite Principal Reference Frame

Centre of Propulsion Module / Launch Vehicle Separation Plane.

Table 3.1-1: SCM & LCM Reference Frames

Figure 3.1-2: SCM & LCM Reference Frames

3.1.3 Mission Phases The LISA Pathfinder spacecraft has the following mission phases: � Launch and Early Operations Phase (LEOP) & Transfer � Commissioning Phase � Demonstration Phase

3.1.4 Structure Configuration The SCM Structure is an eight sided prism with an overall height of ~900 mm and an overall diameter of ~2100 mm to ensure compatibility with the candidate launch vehicle envelopes when mounted on top of the PRM. The structure configuration has a 788 mm internal diameter Central Cylinder with a short cylindrical ring bonded to its base which is the interface to the separation system between the SCM and the PRM (reference AD-3).

LISA Pathfinder


Page 11 of 42



Arranged radially around the Central Cylinder are eight Shear Walls, each enclosed on the open sides by an External Wall, the Top Floor and the Lower Floors. Both the Top Floor and the Lower Floors act as closure panels and are removable for access during AIT phases. The External Walls may also be removed during AIT if access demands it. The two experiments are mounted in the Central Cylinder, with the LTP Optical Bench mounted between walls that occupy the top two-thirds of the cylinder, and the DRS Sensor Assembly mounted in the lower third on a circular panel that forms a physical barrier between it and the LTP. An exploded view of the SCM Structure is shown in Figure 3.1-3.

Figure 3.1-3: Exploded View Of Structure SCM-83/RD-71/R

The SCM Structure configuration shall comply to the interfaces defined in AD-3.

SCM-84/RD-71/R The flight SCM Structure shall comprise of the items listed in Table 3.1-2.

LISA Pathfinder


Page 12 of 42



DESCRIPTION QUANTITY CATEGORYScience Spacecraft/Propulsion Module Adaptor Ring

1 1

Central Cylinder (including compensation mass mounting)

1 1

LTP Shear Wall 2 1 LTP Support Wall 2 1 LTP Base Plate 1 1 LTP Top Closure Panel 1 1 LTP Side Closure Panel 2 1 DRS Base Plate 1 1, 2 Parallel Shear Wall 4 1 Radial Shear Wall 3 1 Radial Shear Wall (for DRS Electronics Assembly)

1 1,2

Short External Wall 2 1 Medium External Wall 4 1 Long External Wall 2 1 Top Floor 1 1, 2 Outer Lower Floor 2 1 Inner Lower Floor 1 1 Pressurant Tank Support Structure including mounting bracket

4 1

Assembly hardware (see note 1) 1 set 1 Star Tracker Bracket 1 3 Gyro brackets 2 3 LGA brackets 2 3 MGA bracket 1 3 Electrical Connector brackets 1 set 3 Cold Gas Fill and Drain Bracket 2 (TBC) 3 Umbilical Brackets 10 3 Separation spring brackets 4 3 Grounding straps and rails 1 set 3 Equipment attachment fasteners (see note 2) 1 set 3 Thermal doublers (see note 3) 1 set 4 Category 1 : Core structural items. Category 2 : Core structural items that will be delivered to identified sites; replacement dummy panels will be delivered with structure at DRB Category 3 : Equipment mounting hardware. Category 4 : Delivered but not included in mass budget Note 1 : ‘Assembly hardware’ shall include all the fasteners, cleats, etc to build the structure and to attach all brackets. Note 2 : ‘Equipment attachment fasteners’ relates to all items assembled to the structure including the propulsion equipment and pipework, harness etc and are defined in AD-3. Note 3 : ‘Thermal doublers’ are defined in AD-3.

Table 3.1-2: Flight Structural Items SCM-86/RD-71/R

In addition to the flight structural items, the dummy structural items listed in Table 3.1-3 shall be provided. These items and their fixations shall be fully flight representative and interchangeable with the flight items they replace.

LISA Pathfinder


Page 13 of 42



DESCRIPTION QUANTITY CATEGORYDummy DRS Base Plate (see Note 1) 1 5 Dummy Shear Wall (see Note 2) 1 5 Dummy Top Floor (see Note 3) 1 5 Category 5 : Structural items that will be used for the StM static and separation tests, but will be replaced during AIT by the flight panels. Note 1 : Substitutes for the flight DRS Base Plate which is provided to supplier for integration of DRS Sensor Assembly. Note 2 : Substitutes for one flight Shear Wall which is provided to supplier for integration of DRS Electronics Assembly. Note 3 : Substitutes for flight Top Floor which is provided to supplier for integration of solar array.

Table 3.1-3: Dummy Structural Items SCM-88/RD-71/R

The SCM Structure panels shall include all structural, grounding and equipment inserts and all necessary surface treatments, excluding thermal finishes such as paints and radiator (SSM) tapes.

SCM-89/RD-71/R Removable panels shall include interface points that are available for use with GSE (handles). The location of these interface points are defined in the AD-3.

SCM-90/RD-71/I The SCM Structure shall be fitted with calibrated strain gauges at critically loaded locations to assist in the system level SCM Structure test. The SCM Structure supplier shall identify the number and locations required.

SCM-91/RD-71/R The SCM Structure configuration shall be as defined in detail in AD-3.

SCM-93/RD-71/R The SCM Structure shall provide the physical interfaces to all equipment or units. This includes fasteners (bolts, washers, nuts), brackets, shims, cut-outs, etc.

SCM-494/RD-71/R For units and brackets requiring thermal washers/spacers the fasteners and local structure design shall take into account the spacer parameters as defined in AD-3.

Provision of the thermal spacers/washers will not be part of the structure responsibility.

SCM-94/SRS-202;RD-71/R The SCM Top Floor, Lower Floors, DRS baseplate, LTP panels and External Walls shall all be removable from the SCM Structure for integration of all elements of the experiments and service subsystems prior to the re-integration of the panel to the SCM.

SCM-95/SRS-202;RD-71/R The Shear Wall for the DRS Electronics Assembly shall also be replaceable to enable integration of the DRS Electronics Assembly to the Shear Wall independently of the SCM static test.

SCM-1101/RD-71/R The DRS panels shall be designed to allow their removal and replacement with all the DRS equipment mounted on them.

SCM-1128/RD-71/T,A All removable panels shall be designed to ensure that the position of the panel datum point does not vary by more than 0.1mm with respect to a fixed structure datum following any removal/replacement operation.

LISA Pathfinder


Page 14 of 42



SCM-1105/RD-71/R The SCM structure shall provide attachment points allowing horizontal hoisting and suspension for the purpose of performing thermo-elastic distortion measurements on the bare structure.

SCM-1106/RD-71/R The SCM structure shall accomodate compensation masses mounted on the spacecraft panels. Detailed interfaces for these items shall be as defined in AD-3.

SCM-496/SRS-795;RD-71;RD-65/A The SCM structure and deliverable GSE shall be compatible with the AIV handling cases defined in Table 3.1-4 when it is subjected to the AIV handling loads identified in Table 5.2-2. The various configurations are illustrated in Figure 3.5-1 to Figure 3.5-4 inclusive.

LOAD CASE VS BUILD CONFIGURATION ORIENTATION AIV ACTIVITY A B C D

S/C Z-Vertical 1 1 1 1 S/C X-Vertical N/A 1 1 1 S/C Y-Vertical

SCM Spacecraft on its own; I/Fs at upper lifting points (& lower I/F when

Z-horizontal) N/A 1 1 1 S/C X-Vertical 1,3 1,2,3 1,2,3 1,2,3,4 S/C Y-Vertical N/A 1,2,3 1,2,3 1,2,3,4 S/C Z-Vertical

SCM mounted via clamp-band at its separation plane (e.g. on turnover

trolley). N/A 1,2,3 1,2,3 1,2,3,4 S/C X-Vertical N/A 3 3 3 S/C Y-Vertical N/A 3 3 3 S/C Z-Vertical N/A 3 3 3 S/C Z-Vertical

(Inverted)

SCM mounted via upper interface points

N/A 1g 1g 1g

S/C Z-Vertical SCM supported at upper I/Fs only; supporting PRM+adapter.

N/A N/A 1 1

Definitions: A: Core Structure; no external outer-walls; no top floor/DRS panels; all units installed on core structure. B: Complete SCM including sidewalls; all units installed BUT top-floor and/or lower floor/DRS panel removed. C: Complete SCM; all equipments installed BUT any one single external sidewall only removed. D: Fully integrated SCM. Note: (i) The numbers 1, 2, 3 &4 denote the separate load cases defined in Table 5.2-1. (ii) Deliverable GSE shall replace removable panels if load case drives design.

Table 3.1-4: AIV Handling Cases SCM-96/RD-71/R

The SCM Structure shall accommodate the LTP and DRS experiments as defined in AD-3. (Note that the LTP struts and brackets are not the responsibility of the SCM Structure supplier).

SCM-99/RD-71/R The Top Floor shall accommodate the solar array as defined in AD-3 and AD-6. To ensure electrical isolation between the solar array and the SCM Structure, the external surface of the Top Floor shall be delivered fitted with a 50 (TBC) micron layer of Kapton film. The Kapton film shall provide suitable adhesion to support 1.5kg/m2 of solar cells taking into account the mechanical and thermal environments specified in SCM-282 and SCM-316. Verification testing shall include at least wet-insulation tests, bonding verification (including peel) testing, grounding tests. AD-6 provides specific requirements from the solar array supplier to ensure suitability of the panel/kapton substrate properties for solar cell accomodation.

Note: The structure supplier is responsible for demonstrating the processes regarding bonding of the kapton to the panel; the solar array supplier is responsible for demonstrating processes regarding integration of the solar cells and harness to the panel. This latter will entail development testing to be performed by the solar array supplier using flight representative samples.

SCM-1130/RD-71/R Flight representative coupon samples of the top floor (including kapton) shall be delivered, sufficient (in size and number) to allow the solar array subcontractor to perform development tests.

LISA Pathfinder


Page 15 of 42



SCM-102/SRS-177;SRS-1153;SRS-189;RD-71/R

The SCM Structure shall accommodate the following elements of the Cold Gas �Propulsion subsystem:- � three Cold Gas Thruster Cluster Assemblies, � three Closed Loop Control Electronics (CLCE), � one pressurant feed assembly (including Proportional Electronic Pressure Regulator (PEPR)), � up to four pressurant storage tanks (TBC). Detailed interfaces for these items shall be as defined in AD-3.

SCM-504/SRS-177;RD-71/R The pressurant tank mounts shall be designed to take into account tank expansion/contraction and interface degrees of freedom as identified in AD-3.

SCM-103/SRS-177;RD-71/R

The SCM Structure shall accommodate the following elements of the FEEP �Propulsion subsystem:- � three FEEP Thruster Cluster Assemblies, � three FEEP Power Conditioning Units (PCU), � one FEEP Diagnostics Package (FEDP) consisting of a Plasma Probe Assembly, Interface Electronics Assembly, a Microbalance Assembly and a Solar Cell Assembly. Detailed interfaces for these items shall be as defined in AD-3.

SCM-104/RD-71/R The SCM Structure shall accommodate the following elements of the avionics and Power Subsystem:- � one On Board Computer (OBC), � up to three battery modules, � one Power Conditioning & Distribution Unit (PCDU). Detailed interfaces for these items shall be as defined in AD-3.

SCM-105/RD-71/R The SCM Structure shall accommodate the following elements of the Telecommand & Telemetry Subsystem:- � one Medium Gain X band communications antenna, � two Low Gain X band communications antenna, � two Solid State Power Amplifiers (SSPA), � two transponders, � one set of RF switches, isolators, diplexers and a coupler, �� Coax/wave guide (including supports, fixations and cut-outs). Detailed interfaces for these items shall be as defined in AD-3.

SCM-106/RD-71/R The SCM Structure shall provide a support bracket for the Medium Gain X band communications antenna that shall guarantee that the mounting plane can be aligned to an accuracy of 0.75 degrees with respect to the SCM alignment frame. Detailed interfaces shall be as defined in AD-3.

SCM-107/RD-71/R The SCM Structure shall provide support brackets for the two Low Gain X band communications antennas located on the SCM Structure such that their pointing is nominally in the +X-Y direction and -X+Y direction respectively in the nominal operational mode of the SCM. Detailed interfaces for these items shall be as defined in AD-3.

SCM-505/RD-71/R The structure shall provide interfaces for accommodating electrical harness (including cut-outs, support structures, tie-bases, inserts etc) as defined in AD-3.

LISA Pathfinder


Page 16 of 42



SCM-108/RD-71/A The SCM Structure shall accommodate the following elements of the AOCS:- � two Autonomous Star Trackers (AST), � three Digital Sun Sensors (DSS), � two Gyro assemblies. Detailed interfaces for these items shall be as defined in AD-3.

SCM-110/RD-71/R The SCM Structure shall provide a support bracket for each of the two Autonomous Star Trackers that shall guarantee that they shall be aligned to the accuracy specified in Table 3.1-5. Detailed interfaces for these items shall be as defined in AD-3.

SCM-113/RD-71/T,A The SCM Structure shall provide the capability to accommodate the DSS to the accuracy specified in Table 3.1-5.

SCM-111/RD-71/T,A The SCM Structure shall provide a support bracket or brackets for the Gyro units or Gyro assemblies that shall guarantee that each shall be aligned to the accuracy specified in Table 3.1-5. Detailed interfaces for these items shall be as defined in AD-3.

SCM-101/RD-71/R The SCM Structure supplier shall provide full contact peelable shim packs (each 4 mm thickness and 40 micron peel) for alignment of AST, DSS and Gyros. These shims will be installed between unit and bracket and/or between bracket and SCM structure.

SCM-114/SRS-1119;SRS-1120;SRS-1110;SRS-1111;SRS-1113;SRS-1114;RD-71/T,A The SCM Structure shall provide AOCS unit alignment knowledge as defined in Table 3.1-5.

UNIT MOUNTING ACCURACY 1

ALIGNMENT KNOWLEDGE 1

REMARK

Autonomous Star Trackers (AST)

�0.1� �30” Three axes.

Digital Sun Sensors (DSS)


Gyro Assemblies


Note 1 : alignment cube w.r.t. satellite reference frame.

Table 3.1-5: AOCS Unit Alignment Requirements SCM-116/RD-71/R

The SCM Structure shall provide alignment sight line holes in the relevant SCM Structure panels for the AST and Gyro alignment cubes in accordance with requirements defined in AD-3.

SCM-117/RD-71/R The SCM Structure shall provide two fixed optical reference cubes for system alignment activities. The cubes shall be produced from flight grade materials and be delivered complete with protective covers for AIV activities. Detailed interfaces for these items shall be as defined in AD-3.

SCM-118/RD-71;RD-64;SRS-457/T,R The SCM Structure shall provide inserts in each panel for accommodating a tooling ball/alignment tool to enable the locations of the units subsequently fitted to be accurately measured. The location of all equipment inserts in the panel shall be measured with reference to these positions. Detailed interfaces shall be as defined in AD-3.

LISA Pathfinder


Page 17 of 42



SCM-1131/RD-71/T,I Repeatability of measurements of insert positions shall be better than 0.02mm (TBC), including removal/reinstallation of tooling devices, if relevent.

SCM-119/RD-71/R The SCM Structure shall provide the electrical connector brackets defined in Table 3.1-6. Detailed interfaces for these items shall be as defined in AD-3.

CONNECTORS QUANTITY TYPELV Um bilical 2 Fly Off PRM Umbilical 8 Fly Off Solar Array Interface 2 Skin Safe/ Arm 3 Skin RCS Test 1 Skin Electrical Test 10 Skin Miscellaneous 5

Table 3.1-6: Connector Brackets SCM-121/RD-71/R

The SCM Structure I/F Ring shall be compatible with the interfaces of the PRM Upper I/F Ring and separation system as defined in AD-3.

SCM-122/RD-71/I The SCM Structure shall provide a Fill and Vent Valve bracket which will be positioned for easy access when the SCM is mounted on the PRM as defined in AD-3.

SCM-506/RD-71/R The SCM structure shall accommodate elements of the thermal subsystem (thermal fillers, spacers, thermal blankets, inserts etc) in accordance with AD-3. Thermal doubler shall be installed on certain panels of the SCM as defined in AD-3.

SCM-123/SRS-1593;RD-71/T The SCM Structure shall provide interface points capable of lifting the fully integrated and fuelled LCM and the launch vehicle adaptor.

SCM-124/SRS-1593;RD-71/R The lifting points shall be compatible with the lifting brackets (see also Section 3.5), and shall be accessible when the SCM is integrated to the PRM.

3.1.5 Mass SCM-126/RD-71/T

The SCM Structure mass shall be minimised, and less than 82.7 kg including margins. This shall include the items listed in Table 3.1-2, and shall declare the mass for each category separately.

Note : The mass margin philosophy to be applied is defined in AD-1.

SCM-507/RD-71/A The SCM shall be designed taking into account the unit mass distributions defined in AD-4.

Note: These masses are defined for design purposes only and are conservative. They include worst case margins and distributed masses and may not reflect the true predicted masses of the units. Two sets of mass distributions shall be taken into account by the Supplier: �� Initial Mass Distribution for Preliminary Design, �� Final Mass Distribution for Detailed Design (Pre CDR).

LISA Pathfinder


Page 18 of 42



3.2 Interface Requirements SCM-129/RD-71/T,A

The maximum displacement of any edge of the SCM Structure relative to the diametrically opposite edge of the panel in response to handling, transportation, launch environment (as defined in this specification) and thermo-elastically induced (taking into account the thermal cases defined in AD-5) Design Loads shall not exceed:- � displacement in SCM Structure X axis : 0.25 x 10-3 m � displacement in SCM Structure Y axis : 0.25 x 10-3 m � displacement in SCM Structure Z axis : 0.25 x 10-3 m � rotation about the SCM Structure X axis : 1.0 x 10-3 radians � rotation about the SCM Structure Y axis : 1.0 x 10-3 radians � rotation about the SCM Structure Z axis : 1.0 x 10-3 radians

3.2.1 LTP Interfaces SCM-131/RD-71/T,A

The maximum displacement of the SCM Structure at the LTP Core Assembly mounting interfaces in response to handling, transportation, launch, flight (as defined in this specification) and thermo-elastically induced (taking into account the thermal cases defined in AD-5) Design Loads shall not exceed:- � displacement in SCM Structure X axis : 0.25 x 10-3 m � displacement in SCM Structure Y axis : 0.25 x 10-3 m � displacement in SCM Structure Z axis : 0.25 x 10-3 m � rotation about the SCM Structure X axis : 1.0 x 10-3 radians � rotation about the SCM Structure Y axis : 1.0 x 10-3 radians � rotation about the SCM Structure Z axis : 1.0 x 10-3 radians

3.2.2 Separation System Interfaces SCM-133/RD-71;RD-68/I,R

The SCM Structure shall interface with the PRM through an interface ring of 800 mm diameter as defined in AD-3.

SCM-135/RD-71/R The SCM Structure shall provide brackets to support the 10 "fly off" umbilical connectors that allow electrical connection between the SCM and PRM in accordance with AD-3.

3.3 Mechanical Design Requirements

3.3.1 Functional Requirements SCM-138/SRS-452;RD-71/A

The SCM Structure shall maintain the required alignment defined in Table 3.1-5 during ground and in-orbit operations.

SCM-139/AD-2;RD-71/A The SCM Structure shall be protected against corrosion, moisture and stress corrosion.

SCM-140/SRS-443/R Metallic materials used in structural applications shall have a high resistance to Stress Corrosion Cracking (SCC) and shall be chosen from Table 1 of ECSS-Q-70-36.

SCM-141/SRS-795;RD-71/R The structure design shall not impede access to connectors.

LISA Pathfinder


Page 19 of 42



SCM-142/SRS-202;RD-71/R The mechanical design shall allow removal, maintenance and re-installation of all secondary structures, equipment and the payload.

SCM-143/RD-71/R The SCM Structure shall be designed to provide sufficient access to enable the mounting and removal of all equipment (including harness connectors) using standard tools.

3.3.2 Performance Requirements SCM-145/SRS-447;RD-71/A

The SCM structural design shall provide a minimum margin of +15% over the following frequencies :- � a first lateral frequency greater than or equal to 43.5 Hz; � a first axial frequency greater than or equal to 82.5 Hz; in launch configuration with fixed base at I/F Ring.

SCM-147/SRS-450;SRS-452/A The structural performance of all elements shall be verified taking into account worst case design or material uncertainties and the maximum mass of the element.

3.4 Electromagnetic Compatibility SCM-149/RD-71/R

The structure shall provide all hardware necessary (e.g. structure mounted grounding studs, rivets, grounding straps & attachments, ground reference points/rails etc) to provide the ground return for all equipment, harness & structure. Ground reference rails (required to guarantee adequate grounding on a CFRP structure) & unit grounding points shall be located as defined in AD-3.

SCM-157/RD-71/R A unit grounding point shall be provided in the structure panel for each unit.

SCM-158/RD-71/R Two grounding points shall be provided on the external face of each external structure panel for grounding of external thermal blankets.

SCM-159/RD-71/T,R Grounding straps shall be provided between each structure panel to ensure continuous ground to the master grounding point on the I/F Ring.

SCM-160/RD-71/R The structure shall provide the master grounding point on the I/F Ring.

SCM-161/RD-71/R The maximum dimension of any gap between structure panels shall not exceed 5 mm.

3.5 MGSE Requirements SCM-164/RD-71/T

MGSE shall be designed for the execution of assembly, integration, verification, transportation, launch support and maintenance of SCM Structure items and spares.

SCM-165/RD-71/T The MGSE shall comply with requirements and safety standard imposed by the facility in which it has to operate.

LISA Pathfinder


Page 20 of 42



SCM-167/RD-71/T MGSE shall be proof tested to 2 times the maximum expected load (considering the maximum load cases defined in SCM-178 and SCM-479).

SCM-168/SRS-744/R The SCM Structure supplier shall be responsible for all MGSE required to manufacture and assemble the SCM Structure at the supplier premises and for the defined deliverable MGSE items.

SCM-478/SRS-744;RD-71/R The SCM Structure supplier is required to provide transportation containers for the Category 2 items identified in Table 3.1-2, specifically:- � for transporting the flight DRS Base Plate and Radial Shear Wall for DRS Electronics Assembly to the DRS supplier, � for transporting the flight Top Floor to the solar array supplier, and following integration of the solar array on to the Prime contractor's AIT facility.

SCM-510/RD-71/R The solar array container shall take into account internal volume constraints as identified in the MICD for special packaging that will be required (and provided by) the solar array subcontractor for delivery of the integrated solar array onto the Prime contractor's AIV facility.

The SCM Structure supplier shall note the Ground Operations Loads defined in Table 5.2-1 which remain applicable during all SCM integration phases.

SCM-1093/RD-71/T,A SCM structure and GSE shall be compatible with the various integration configurations illustrated in Figure 3.5-1 to Figure 3.5-4 inclusive.

LISA Pathfinder


Page 21 of 42



(A) SCM Vertical Hoisting LIFTING FRAME(*) SLINGS(*) LIFTING BRACKET(S)(*) SCM

�� SCM supported by Lifting Frame Assembly, �� Lifting Brackets installed onto lifting interfaces, �� Items marked (*) to be provided by SCM structure supplier.

(B) SCM Horizontal LIFTING FRAME(*) SLINGS(*) UPPER LIFTING ASSEMBLY AIT UPPER ADAPTER (FOR INVERTED INSTALLATION ON TROLLEY) AIT ADAPTER (AND CLAMP-BAND) SCM (TOP FACE)

�� SCM supported by adapter secured by clampband to separation plane interface and Upper Lifting Assembly (attaching to upper lifting points and installed while SCM is on turn-over trolley),

�� SCM plus adapters and lifting assemblies hoisted using SCM Lifting Frame & Slings and rotated through 180o.

Figure 3.5-1: Integration Configuration: SCM Hoisting

SCM SEPARATION PLANE AIT ADAPTER (AND CLAMP-BAND) TURN-OVER TROLLEY

�� SCM supported by adapter secured by clampband to separation plane interface, �� SCM maybe rotated so that any axis may be horizontal.

Figure 3.5-2: Integration Configuration: SCM Mounted via Clampband at Separation Plane

LISA Pathfinder


Page 22 of 42



SCM (SEPARATION PLANE) SCM (TOP FACE) UPPER LIFTING ASSEMBLY AIT UPPER ADAPTER TURN-OVER TROLLEY

�� Objective of this configuration is to allow installation of DRS in central cylinder. �� SCM installed on turn-over trolley via Upper Lifting Assembly, �� AIT adapter and Lifting Frame Assembly removed, �� SCM subsequently rotated until –Z face is upwards. �� DRS installed in –Z section of cylinder.

Figure 3.5-3: Integration Configuration: SCM Inverted Mounting LIFTING FRAME(*) SLINGS(*) LIFTING BRACKET(S)(*) SCM PRM ADAPTER + CLAMP-BAND

�� SCM, PRM & Adapters supported by Lifting Frame Assembly; �� Lifting Brackets installed onto SCM lifting interfaces, �� PRM fully loaded with propellant, �� Items marked (*) to be provided by SCM structure supplier.

Figure 3.5-4: Integration Configuration: SCM +PRM Hoisting SCM-175/RD-71/T

The SCM Structure supplier shall provide a SCM Lifting Assembly capable of lifting the fully integrated, fully fuelled LCM in a vertical orientation. The Lifting Assembly shall comprise: �� A Lifting Frame, �� Lifting Strops, �� Lifting Brackets, �� Fixations as required.

LISA Pathfinder


Page 23 of 42



SCM-176/RD-71/R The SCM Lifting Slings shall include lifting brackets which interface to the SCM lifting points.

SCM-177/RD-71/T The SCM Lifting Assembly shall include lifting slings capable of lifting:- � the fully integrated SCM including Top Floor/solar array (horizontal or vertical); � the fully integrated SCM without Top Floor/solar array (horizontal or vertical); � the fully integrated, fully fuelled LCM plus GSE (with a test or flight adapter and clamp band).

Note: Horizontal lifting and inverted mounting shall be performed in conjunction with Customer provided adapters attached at the separation plane interface and the upper lifting interface. SCM-178/SRS-1593;RD-71/T

The SCM Lifting Assembly shall be designed to lift the fully integrated, fully fuelled LCM plus GSE (with a test or flight adapter and clamp band) with a total mass of not less than 2250 kg. This comprises the PRM and adapter (see SCM-178 for mass properties) and the maximum mass SCM (500kg).

SCM-179/RD-71/A MGSE shall be designed taking into account the following factors:- General MGSE Items � Yield Factor = 1.5 � Ultimate Factor = 2 Lifting Devices � Yield Factor = 2 � Ultimate Factor = 3 MGSE used as test rigs � Yield Factor = 2 � Ultimate Factor = 4

SCM-180/RD-71/R All MGSE will have grounding points. These points will be accessible during all activities.

SCM-181/RD-71/R All MGSE in use must be compliant with European legislation on Product Liability as specified in AD2, section 11.

SCM-182/RD-71/A,R The design of the MGSE shall be such that risks to either human health or to the integrity of the supported SCM Structure/equipment during its use is minimised.

SCM-183/RD-71/R All like parts of MGSE shall have the same part number. Each equipment item shall be directly interchangeable in form, fit and function with other equipment of the same part number. The performance characteristics shall permit equipment interchange with a minimum of adjustments and re-calibrations. The equipment must be of the same qualification status and reliability to meet interchangeability requirements.

SCM-184/RD-71/R All fasteners associated with MGSE shall be metric, stainless steel with a minimum grade of A2-70.

SCM-185/RD-71/R MGSE shall be designed to give an operational life of 10 years without the need for major refurbishment other than repairs due to mishandling.

LISA Pathfinder


Page 24 of 42



SCM-186/RD-71/A,R MGSE that will be transported by air shall remain serviceable after experiencing an atmospheric pressure change corresponding to a descent of not greater than 920 meters/min.

SCM-187/RD-71/A,R MGSE that will be transported by air shall remain serviceable after experiencing an atmospheric pressure corresponding to that experienced at sea level up a height of 11,000 metres.

SCM-1100/RD-71/T,A MGSE shall be designed to survive, without damage, the transport and storage environments in relation to expected shock inputs. The maximum, worst case, expected shock due to mishandling will be the shock equivalent to an edge drop with the MGSE dropping 100 mm onto concrete, as a result of a crane or lifting device failure.

SCM-189/RD-71/R MGSE shall be of modular design and construction where practicable, such that any damage due to rough handling during transportation can be repaired with the minimum amount of dismantling.

SCM-190/RD-71/A,R The dimensions of MGSE shall be kept to the minimum, consistent with performing its function. Its width and length in its operational condition shall be compatible with the requirement to be inherently stable in all operational modes.

SCM-191/RD-71/R MGSE shall be as light as is practical, consistent with performing its function. The materials used in the design of the MGSE shall be chosen so as to minimise its weight, whilst maintaining the desired strength characteristics.

LISA Pathfinder


Page 25 of 42



4. GENERAL DESIGN AND INTERFACE REQUIREMENTS See also Section 6 for GDIR Applicability.

4.1 Product Assurance SCM-196/AD-2/T,A,I,R

AD-2 shall apply in it's entirety; those requirements of AD-2 particular to the product shall be reflected in the organisations PA Plan.

4.2 General Design Requirements

4.2.1 Design Safety SCM-199/AD-2;RD-71/R

All elements of the system shall be designed to minimise hazards to personnel and property.

SCM-200/AD-2;RD-71/R Design choices likely to create safety concerns shall be identified and submitted to Prime (and the Agency) for approval.

4.2.2 Venting SCM-204/RD-71/A

The alignment stability requirements of any item that does not include venting provisions shall not be compromised by any resulting deformations due to internal pressure.

4.2.3 Identification & Marking SCM-206/AD-2;RD-71/I

Identification nameplates shall be mounted on the lower (PRM I/F) ring and on the external surface of each removable SCM Structure Panel. Each nameplate shall be visible when installed on the SCM Structure, shall not interfere with any interfacing item and its location shall be noted on the ICD. Identification nameplate shall meet the requirements of AD-2.

4.2.4 Transportation, Handling and Storage

4.2.4.1 Handling SCM-211/RD-71/R

Any item of structural hardware weighing more than 10 kg (including removable structural panels whose mass with units installed exceeds 10kg) shall be supplied with GSE to aid in its installation. For the smaller units, this could be removable handles, however heavier or larger units shall be supplied with MGSE handling frames. Such GSE shall be common for all similar items to be handled. As any other piece of hardware used only during ground operations, such handles shall be clearly identified as non-flight item (red anodised or painted and a red flag carrying the notation "NOT FOR FLIGHT" attached to them) as specified in AD2, section 3H. Such items shall be clearly identified on the relevant Interface Control Drawing.

4.2.4.2 Thermally Conductive Materials SCM-213/RD-71/I

The SCM Structure shall be compatible with the use of any thermally conducting interface filler, used between a unit and the surface on which it is mounted. The filler will nominally be a non-curing gasket type, however, a grease or curing rubber/adhesive may be used and the structure shall be compatible with these.

LISA Pathfinder


Page 26 of 42



4.2.5 Parts Material and Processes SCM-215/AD-2;SRS-443/A

Materials, mechanical parts and processes intended for use on the SCM Structure must be selected in accordance with the requirements detailed in AD-2. In particular, all materials, mechanical parts and processes must be subject to a criticality analysis against the requirements detailed in AD-2.

SCM-216/AD-2;SRS-443/T,A All critical materials, mechanical parts and processes must be subject to evaluation and validation/qualification and subsequent RFA approval against LISA Pathfinder mission requirements prior to incorporation into the SCM Structure. Critical items must also be included on the Critical Items List for the LISA Pathfinder mission, refer to AD-2.

4.3 Mechanical Design and Interface Requirements

4.3.1 Structural Design SCM-219/RD-71/I

For the DRS Sensor Assembly I/F and LTP Core Assembly I/F, the actual equipment insert centre positioning shall be within a circle of 0.1 mm diameter of the theoretically required centre position defined in AD-3.

SCM-220/RD-64/I For all other equipments, the actual equipment insert centre positioning shall be within a circle of 0.2 mm diameter of the theoretically required centre position defined in AD-3.

SCM-1097/RD-71/A The attachment between the top floor (solar array panel) and the rest of the SCM structure shall be designed in order to minimise the thermoelastic distortion effects generated by the top floor.

SCM-1103/RD-71/A The interface between the solar array and the rest of the SCM structure shall limit heat flow across the interface to less than 0.25 W/K.

SCM-484/RD-71;RD-64/I Four M4 inserts for mounting of an alignment tool shall be provided in each SCM Structure Panel. The location of all equipment inserts on this panel shall be measured with reference to these four positions. Detailed requirements are provided in AD-3.

SCM-221/RD-71/I Unless otherwise stated in AD-3, the level of the insert top face relative to the panel surface should be:- �� flush to subflush by 0.05 mm for all equipment mounting applications, �� flush to proud by 0.1 mm for all structural mounting applications.

SCM-222/RD-71/T If bonded joint technology is used, then these shall be proven by a specific test programme which shall include a minimum of 10 thermal cycles prior to mechanical testing of the joints.

SCM-224/SRS-1596/R Titanium alloy fasteners and fasteners smaller than M5 are not allowed for safe-life design implementations of the structure.

LISA Pathfinder


Page 27 of 42



SCM-226/SRS-452;RD-65/A The SCM Structure shall be able to withstand, without failure (including significant permanent deformation or deformation detrimental to the specified performances) the worst case expected combination of the required loads and associated environments encountered during ground and in-orbit operational phases and taking into account all safety factors specified. These include manufacturing, assembly, testing, transport, launch and in-orbit operations. All mechanical elements shall demonstrate positive margins of safety when calculated as follows:

MoS = Allowable load/stress (yield/ultimate) - 1

Applied load/stress x safety factors (FOSN x KADD x FOSPF)

Where: Allowable load is the allowable load under specified functional conditions (e.g. yield, buckling, ultimate), Applied load is the computed or measured load under defined load conditions, i.e. the Design Load (DL), Safety factors (denoted FOSN) are the applicable factors of safety applicable to the specified load condition (e.g. yield (FOSY), buckling (FOSB), ultimate(FOSU)).

SCM-229/SRS-453;RD-65/T,A The loads for designing the SCM structure shall be determined by application of load factors as defined in Figure 4.3-1.

x Qualification Factor, KQ x Design Factor, FOSD x Uncertainty Factor, FOSUN x Protoflight Factor, FOSPF x Yield Factor, FOSY x Ultimate Factor, FOSu x Buckling Factor, FOSB

Design Load (DL)

Yield Load

(YL)

Ultimate Load

(UL)

Buckling Load

(BL)

Flight Limit Load(LL)

Qualification Load (QL)

Figure 4.3-1: Load Factor Philosophy for Definition of Design Loads The Flight Limit Load, LL, is the load that can be encountered during the life of the structure that results from the flight environments. These are expected to be during the launch phase but also include combinations of thermally induced loads, preloads, inertia loads (e.g. for mechanisms).

Design Load, DL is derived by the multiplication of the (Flight) Limit Load by the relevant factors of safety. These include the Design Factor, FOSD and where appropriate an Uncertainty Factor, FOSUN where design

LISA Pathfinder


Page 28 of 42



loads are generated using FE analyses. For equipments/assemblies following a protoflight development philosophy, an additional Protoflight Factor of Safety, FOSPFM shall be applied to the FLL to cover additional risks for equipments/assemblies following a protoflight development philosophy. i.e. The Design Load = Limit Load x FOSD x (FOSUN x FOSPF where applicable).

SCM-231/SRS-736; SRS-1578;RD-65/A For SCM structural design the minimum design factor of safety shall be FOSD = 1.25.

SCM-514/SRS-827;RD-65/A A Protoflight Factor of Safety, FOSPF of 1.1 shall be taken into account in the design of the structure.

SCM-736/SRS-453;RD-65/ Where design loads are generated using FE analyses, then an additional Uncertainty Factor, FOSUN shall be added to the Design factor where FOSUN shall not be less than 1.1.

SCM-735/SRS-453;RD-65/A The factors of safety to be applied to the SCM structure are as defined in Table 4.3-1.

COMPONENT/LOAD TYPE NON PRESSURE LOAD CASES 1, 2, 3

YIELD FOSY

ULTIMATE FOSU

BUCKLING FOSB

Conventional Material/Metallic Structure

1.1 1.4 1.6

Non-metallic Structures 1.2 1.6 1.6

Notes:

1. For combined loads where L(P) is the load due to maximum expected operating pressure and L(M) is the non-pressure limit load, the factored, ultimate load case shall be : 1.5 L(M) + 1.5 L(P).

2. For load cases involving thermal and/or moisture desorption loads, the thermal/moisture desorption stress at the applicable temperature shall be factored by 1.5 to determine the equivalent ultimate thermal/ moisture desorption load and this shall be added to 1.5 times the non-pressure load and/or the pressure load.

3. Where pressure and/or temperature and/or moisture desorption relieve the non-pressure load a Factor of Safety of 1.0 shall be used for the pressure and/or thermal and/or moisture desorption loads. In this case the pressure load shall be based on the minimum operating pressure.

4. CFRP may be considered as a conventional material for purposes of defining safety factors.

Table 4.3-1: Design Safety Factors SCM-246/SRS-453;RD-65/A

The calculation of Margin of Safety, MoS, shall take into account the additional safety factors defined in Table 4.3-2.

LISA Pathfinder


Page 29 of 42



MATERIAL KADD Metallic materials, screw, rivet, face wrinkling of honeycomb.

1.0

Carbon Fibre, Honeycomb compression 1.0 Bonding, structural Inserts, joints 1.2 Buckling strength 1.6 Honeycomb in Tension, equipment(axial loading) if specfic tests are done in honeycomb to verify margin

1.7

Honeycomb in Tension, equipment(axial loading) if no testing of insert in honeycomb.

3.6

Metallic Material (ultimate/yield<1.2) if specific tests are done to verify margin.

1.0

Metallic Material (ultimate/yield<1.2) if no testing is done to verify margin

1.7

Cables 3.0 Mechanical stops, shafts and recesses 2.0

Table 4.3-2: Additional Safety Factors SCM-244/SRS-736;SRS-1578;RD-65/A

For acceptance testing of all SCM elements an Acceptance Factor, KA of 1.0 shall be applied to all Flight Limit Loads. For qualification and proof load testing of SCM elements a Qualification/Proof Factor, KQ or KP = 1.25 shall be applied to all Limit Loads.

SCM-228/RD-65/A The SCM Structure shall be able to survive:- � 4 times all mechanical qualification tests plus; � 4 times all mechanical acceptance tests plus; � one launch campaign.

SCM-250/CREATED/T The SCM Structure centre of mass shall be determined with an accuracy of ±0.5 mm

SCM-251/RD-71;SRS-1606/A The SCM Structure moments of inertia shall be determined with an accuracy of better than ±10%.

SCM-252/RD-71/R One attachment hole on each panel shall be specified as the reference hole. This shall be clearly indicated on the mechanical interface drawings by the identification letter R.

SCM-253/RD-71/R The dimensioning of the attachment hole pattern for each insert shall be specified with respect to the Unit Reference Hole.

4.3.2 Design Requirements

4.3.2.1 Attachment Requirements SCM-258/RD-71/I The interface plane flatness of a structure panel under any unit (including external kapton surface of solar array panel) shall be better than:- �� less than 0.1 mm over any 100 mm length, �� less than 0.8 mm over any continuous surface, � less than 0.04mm over any 20x20mm area (solar array panel only) (TBC)

LISA Pathfinder


Page 30 of 42



� and 100 micro-radians of local rotation. SCM-259/RD-71/T

The interface plane flatness of the structure panels at the DRS Sensor Assembly I/F and LTP Core Assembly I/F shall be better than:- � less than 0.05 mm within the mounting plane � and 100 micro-radians of local rotation.

SCM-260/RD-71/R The SCM Structure shall be delivered with all surfaces unpainted.

SCM-261/RD-71/R The structure panels shall be compatible with structural bonding onto the unpainted surface of:- � harness ty-bases, � MLI attachment studs, � thermal doublers, � second surface mirrors, � heaters, � and thermistors.

SCM-262/RD-71/A All bolts shall be sized to prevent sliding under mechanical & thermal environments. Initially a friction coefficient of 0.2 shall be considered for preliminary sizing of the bolts, unless an actual friction coefficient has been measured.

4.3.3 Mechanical Mathematical Model Requirements SCM-267/RD-71/R

All entities in the deliverable SCM Structure Finite Element Models shall be within the number range from 200000 to 299999.

LISA Pathfinder


Page 31 of 42



5. ENVIRONMENT DESIGN REQUIREMENTS

5.1 Atmospheric Conditions

5.1.1 Cleanliness SCM-271/RD-71/R

The SCM Structure design shall be compatible with the cleanliness requirements, and contamination environment encountered during all phases, as defined in AD-2.

5.2 Mechanical Environment SCM-273/RD-71/A

The design loads applicable to the SCM Structure throughout manufacture, integration, test and flight shall be established and maintained throughout the course of the program

SCM-274/RD-71/A The margins of safety for all structural elements for all design loads shall be provided.

5.2.1 Ground Environment SCM-276/RD-65/A

The SCM Structure shall be designed to withstand the cases defined in Table 5.2-1 taking into account the configurations identified in Table 3.1-4.

SCM-277/SRS-1149;RD-65/A The fully integrated SCM Structure shall be designed to withstand all transportation limit load cases defined in Table 5.2-1.

GROUND EVENTS CASE VERTICAL LATERAL ORIENTATION (g) (g) A General Transportation General -3.0 / +2.0 ±2.0 - Any orientation B Road Transportation Rockot -1.2±1.2 ±1.2 - SCM Z-axis horizontal C Space Head Module

Transportation Dnepr -2.72/ +0.5 ±1.03 - SCM Z-axis horizontal

Vertical and lateral are with respect to the ground; negative vertical is towards the ground and includes gravity.

Table 5.2-1: Ground Loads

SCM-479/SRS-1149;RD-65/T The SCM Structure lifting points shall be designed to lift a total mass 2250kg. This includes the PRM (having a mass of 1750 kg and with a CoG lying within 2mm of the SCM Z-axis and located 1550mm below the SCM-PRM interface plane and representing the fully fuelled, fully integrated PRM fitted with test LVA adapter and clamp band) and the maximum mass SCM (500kg).

Accelerations encountered by the SCM during AIV are as per Table 5.2-2. LOAD DIRECTION & MAGNITUDE LOAD CASE LATERAL VERTICAL

#1 Hoisting 0.5g 2g downwards. #2 General factory

Movement 1g 1g ± 1.5g

#3 Controlled Factory Movement

0.5g 1g ± 0.5g

#4 General Transport 2g (ref.) 3g (ref.) Note: All positive vertical accelerations are towards the ground; lateral may be in any direction.

Table 5.2-2: AIV Handling Accelerations

LISA Pathfinder


Page 32 of 42



SCM-1098/SRS-795;RD-71/A Brackets supporting electrical connectors or umbilicals shall be compatible with installation/removal loads of +/- 100 N.

5.2.2 Launch Environment SCM-280/RD-65/A

The SCM Structure shall demonstrate compatibility with the flight limit loads defined in Table 5.2-3. � the positive sign indicates a compressive load; � the lateral loads are circular envelopes; � lateral and axial loads shall be applied simultaneously.

FLL AXIAL LATERAL

ZSC

CASE

FLIGHT EVENT (g) (g)

2 Rockot - QMAX +3.00 ± 0.40 ±2.00 5 Rockot - 1st Stage Engine Cut Off 8.90 / -1.65 ±1.60 9 Dnepr - After LV exit from TLC -1.15 ±0.92

10 Dnepr - 1st Stage Maximum Dynamic Head +3.50 ± 0.50 ±1.15

11 Dnepr - 1st Stage Maximum Acceleration +9.20 ±0.70

12 Dnepr - 2nd Stage Maximum Acceleration +9.50 ±0.23

Notes: (i) Positive Axial is compression; (ii) Lateral may be in any direction perpendicular to spacecraft axial, ZSC. (Subcontractor to identify worst case)

Table 5.2-3: Flight Limit Loads

SCM-519/SRS-790;RD-71/T,A For preliminary design purposes the PRM to SCM interface shall be designed to be compatible with an overflux factor of 10% on top of the peak line loads determined by this analysis.

SCM-282/SRS-687;RD-71/A Quasi Static Flight Loads To design the SCM Structure, the following quasi-static limit loads shall be applied to all units mounted on the SCM:- �� 20g in plane and �20g out of plane for the LTP Core Assembly mounted in the Central Cylinder, �� 20g in plane and �24g out of plane for the DRS Sensor Assembly mounted in the Central Cylinder, �� 22g in plane and �40g out of plane for all units mounted on the Top Floor, �� 20g in plane and �33g out of plane for all other units mounted on the Shear Walls, �� 22g in plane and �36g out of plane for all other units mounted on the External Walls, �� 50g in any single direction for all equipment/connector mounting brackets, The in plane acceleration shall act simultaneously with the out of plane accelerations for all above load cases. �� 25g in any single direction for all structural panels, taking into account the total mass of all equipment mounted onto them.

SCM-1133/RD-71/A Spring pad brackets shall each be compatible with a maximum spring load of 900N (TBC)

LISA Pathfinder


Page 33 of 42



5.2.3 Flight Environment SCM-284/RD-71/A

During orbit and attitude correction manoeuvres the SCM shall be designed assuming that the LCM subjects the SCM structure to the following limit quasi-static loads:- Linear Acceleration:- � In SCM +Z axis 1.20 m/s² � All other axes 0.25 m/s² Angular Velocity:- � About all LCM axes 10.0°/s Angular Acceleration:- � About LCM X & Y axes 10.0°/s² � About LCM Z axis 1.5°/s² Note : see Section 3.1.2 for SCM and LCM reference frame definition.

5.2.4 Mechanical Testing SCM-1102/RD-71/T

The Structure Supplier shall demonstrate by test typical unit interface properties considering the appropriate materials (panel skins, unit, thermal filler), configurations and finishes and determining, in particular, the effective coeefficient of friction of the unit interface.

SCM-1132/RD-71/T Non structural inserts shall be proof load tested prior to delivery of any structural panel.

SCM-286/RD-71/T Prior to delivery the lifting points shall be proof tested at the suppliers premises. All other testing (excluding component/materials tests) will be undertaken as part of the System level test campaigns.

5.2.4.1 Static Testing A static test will be conducted at LCM level to demonstrate the mechanical integrity of the both the SCM Structure and the PRM. This test will qualify the primary load carrying structures of the SCM and PRM by demonstrating their ability to withstand the qualification loads without rupture, collapse, damage or permanent deformation.

For static testing, the flight representative SCM Structure will be attached to the flight PRM by the flight Separation System and subjected to a System level static test. The SCM structure subcontractor shall have full technical responsibility for the conductance of this test from the point of view of ensuring SCM structure qualification is achieved. [Note : the flight representative SCM Structure shall consist of the flight structure except for flight standard dummy panels for:- �� the DRS Base Plate (the flight panel being delivered to the DRS supplier for DRS Sensor Assembly integration and testing), �� one Shear Wall (the flight Shear Wall being delivered to the DRS supplier for integration of the DRS Electronics Assembly).

The test will be performed with representative boundary conditions and shall envelope the flight configuration and load cases. The test article will be mounted in a dedicated test rig capable of introducing representative loads in incremental steps.

As part of the System level Static Test, the following will be tested and verified:- � SCM-295, � SCM-296, � SCM-297, � SCM-298, � SCM-299, � SCM-300,

LISA Pathfinder


Page 34 of 42



� SCM-301, � SCM-302.

SCM-295/RD-71/A The SCM Structure shall provide load introduction points to support static testing without compromising the integrity or stiffness of the structure. The Customer will provide the necessary jacks, pull-systems and load measurement systems. The SCM Supplier shall provide all test hardware (load plates, beams etc) needed to guarantee a suitable distribution of loads into the SCM structure.

SCM-296/RD-71/I The SCM Structure shall be delivered already instrumented with strain gauges.

SCM-297/RD-71/A The locations and orientations of the strain and deflection gauges necessary to record the loads and deflections at the critical positions required to demonstrate structural qualification shall be identified by the supplier.

SCM-298/RD-71/T,A Structural strength tests shall be performed on all safety critical structures (e.g. the primary load paths and primary load introductions such as lifting points) such that the applied loads envelope the qualification load cases specified.

SCM-299/RD-71/T,A A dedicated stiffness test shall be conducted to verify SCM Structure compliance to the stiffness requirements. The SCM Structure stiffness matrix shall be output from the tests.

SCM-300/RD-71/I Following each test phase, a detailed inspection shall be conducted to verify that no part of the SCM Structure has been damaged.

SCM-301/RD-71/T,A After the stiffness test, the test results shall be compared to the analysis predictions and any differences greater than 10% shall be explained and justified.

SCM-302/RD-71/T,A The FE model shall then be correlated to the test results such that the difference between the analysis predictions and test results shall be less than 10%.

5.3 Thermal Environment SCM-316/SRS-469;SRS-793;RD-71/T

The SCM Structure shall be designed to be compatible with the a design temperature range of +80�C to -60�C, with the exception of the Top Floor which shall be compatible with a design temperature range of +130�C to -60�C (TBC). 200 cycles between minimum and maximum temperatures shall be taken into account. Qualification factors in addition to these shall be taken into account as defined in the GDIR.

SCM-317/RD-71/T The performance of adhesively bonded joints shall not be degraded by thermal cycling within the temperature range appropriate to the application as defined in SCM-316.

SCM-1099/SRS-457;RD-71/A The SCM structure design shall take into account the temperature distributions defined in AD-5: �� Thermoelastic distortions at critical interfaces shall be determined, �� Thermally induced stresses shall be accommodated by the structure design.

LISA Pathfinder


Page 35 of 42



6. GDIR APPLICABILITY MATRIX The following table lists the applicable requirements of the GDIR. It contains, in the first column, the Local ID for each applicable GDIR requirement number. The second column contains the GDIR Requirement number and the opening text of the requirement. The third column defines the Applicability Y/N The final column shows the intended verification method

Req No. Reference Applicability Verif. Method

3 General Design and interface Requirements 3.1.1 Lifetime SCM-919 GDI-31:

The on-ground lifetime of flight hardware is defin ... Y R

SCM-920 GDI-32: The Unit shall meet the requirements of this speci ...

Y A,R

SCM-921 GDI-33: The in-orbit lifetime of the satellite is defined ...

Y R

SCM-922 GDI-34: The unit shall be designed with positive margins o ...

Y A,R

SCM-923 GDI-35: Maintenance during storage shall be as limited as ...

Y R

3.1.2 Design Safety SCM-925 GDI-37:

The unit shall be designed and fabricated with com ... Y A

3.1.3 Venting SCM-927 GDI-43:

Unless a cavity is hermetically sealed adequate me ... Y R

SCM-928 GDI-44: Structural members (honeycomb panels, in particula ...

Y T,A

3.1.4 Interchangeability SCM-930 GDI-46:

All spacecraft units of the same part or configura ... Y R

3.1.5 Identification & Marking 3.1.6 Accessibility/Maintainability SCM-933 GDI-52:

The design of the unit, the position of the connec ... Y R

SCM-934 GDI-53: The equipment shall be designed to require a minim ...

Y R

SCM-935 GDI-54: No field maintenance, servicing or adjustment shal ...

Y R

3.1.7 Transportation, Handling and Storage 3.1.7.1 Thermally Conductive Materials SCM-942 GDI-70:

Unless justified and agreed beforehand, any therma ... Y I,R

3.1.7.2 Magnetic Materials 3.1.7.3 Seals SCM-945 GDI-75:

Any seals used shall comply with all the applicabl ... Y R

SCM-946 GDI-76: Any seals requiring periodic replacement during gr ...

Y R

3.1.7.4 Lubricants and Sealants SCM-948 GDI-78:

No lubricants shall be used without the prior writ ... Y R

3.1.7.5 Screw Locking

LISA Pathfinder


Page 36 of 42




SCM-950 GDI-80: All fasteners used on the unit shall be locked by ...

Y I,R

3.2 Mechanical Design and Interface Requirements SCM-952 GDI-82:

All drawings, specifications and engineering data ... Y R

SCM-953 GDI-83: Units shall be compatible with mechanical testing. ...

Y R

SCM-954 GDI-84: Following testing the unit shall be inspected to c ...

Y I

SCM-956 GDI-2058: Any unit (excluding propellant reservoirs) whose a ...

Y A,R

3.2.1 Structural Design SCM-958 GDI-91:

The following failure modes, for units at all leve ... Y A

SCM-959 GDI-92: The unit shall be designed to withstand the enviro ...

Y A,R

SCM-1116 GDI-94: Wherever practical a fail safe design based on red ...

Y A

SCM-1117 GDI-95: In cases where a failsafe design cannot be impleme ...

Y A

SCM-1118 GDI-2045: All potential fracture critical items shall be sub ...

Y A

3.2.1.2 Mass properties SCM-961 GDI-98:

All mass estimations shall be accompanied by the d ... Y T

SCM-962 GDI-100: The mass of an item must be measured with the foll ...

Y T

3.2.1.3 Centre of Gravity and Moment of Inertia SCM-964 GDI-102:

All COG and MOI estimates shall be accompanied by ... Y A

SCM-965 GDI-104: The unit centre of gravity shall be determined wit ...

Y T,A

SCM-966 GDI-105: The unit moment of inertia shall be determined wit ...

Y A

3.2.1.4 Stiffness requirement SCM-968 GDI-114:

The stiffness requirements shall be demonstrated t ... Y T,A

3.2.1.5 Strength Requirements SCM-970 GDI-129:

The units shall be designed with positive margins ... Y A

SCM-972 GDI-131: The internal loads (thermo elastic, pre-stressed m ...

Y A

SCM-973 GDI-132: For the computation of the design loads the maximu ...

Y A

SCM-975 GDI-148: All bolts shall be sized to prevent sliding under ...

Y A

SCM-976 GDI-149: Wherever applicable, rules for general design of b ...

Y R

SCM-977 GDI-150: In addition, in case of combined loads due to ther ...

Y A

SCM-978 GDI-153: Method for evaluation of dimensioning loads/stress ...

Y A

3.2.2 Design Requirements 3.2.2.1 Attachment Requirements

LISA Pathfinder


Page 37 of 42




SCM-981 GDI-161: The attachment points shall provide a controlled s ...

Y I,R

SCM-982 GDI-162: The interface plane flatness of a unit shall be be ...

Y I

SCM-983 GDI-163: The mechanical mounting interface shall be consist ...

Y R

SCM-984 GDI-170: Sufficient clearance shall be allowed between mech ...

Y I,R

SCM-985 GDI-171: Fasteners shall be verified similarly to other str ...

Y A

SCM-986 GDI-173: Fasteners shall be procured and tested according t ...

Y I

3.2.2.2 Alignment Requirements SCM-988 GDI-176:

Units requiring alignment with an accuracy better ... Y R

SCM-989 GDI-177: Optical references are required to withstand all t ...

Y R

SCM-990 GDI-178: Location of optical references for units shall be ...

Y R

SCM-991 GDI-179: The alignment errors shall be included in pointing ...

Y R

SCM-992 GDI-180: Units which require alignment accuracy of ±0.25° o ...

Y R

SCM-993 GDI-183: The mechanical and optical configuration and its i ...

Y A

SCM-994 GDI-184: Interfaces will be subjected to a formal inspectio ...

Y T,I

SCM-995 GDI-185: The issues of ICDs have to be released as defined ...

Y A

SCM-996 GDI-188: The unit alignment reference frame shall have its ...

Y R

SCM-997 GDI-191: Interface Control Drawings shall be provided to th ...

Y R

3.2.4 Mechanical Mathematical Model Requirements SCM-999 GDI-197:

Finite elements models shall be provided for all i ... Y A

SCM-1000 GDI-2075: The use of duplicate element numbers for elements ...

Y R

3.2.4.1 Software/Electronic Files Delivery SCM-1002 GDI-200:

The model shall be prepared using NASTRAN Software ... Y R

SCM-1003 GDI-201: Finite elements models shall be provided for all u ...

Y R

SCM-1004 GDI-202: For the FEM delivery, the following list of inform ...

Y R

3.2.4.2 Units SCM-1006 GDI-204:

S.I. units are to be used: · Newton (N) for force ...

Y R

3.2.4.3 Coordinate system SCM-1008 GDI-206:

The FEM shall use the Units/assembly Reference Fra ... Y R

3.2.4.4 Model Identity/Comment

LISA Pathfinder


Page 38 of 42




SCM-1010 GDI-208: The model name, issue and date must be included at ...

Y R

SCM-1011 GDI-209: The model description shall refer to a configured ...

Y R

SCM-1012 GDI-210: The following comment cards must be included in th ...

Y R

3.2.4.5 Model Size and Identification Numbering SCM-1014 GDI-212:

Numbering of BULK data cards: Each Nastran BULK ca ...

Y R

SCM-1015 GDI-213: Excluded BULK data cards: All data cards used to d ...

Y R

SCM-1016 GDI-214: The authorised NASTRAN elements are the following: ...

Y R

SCM-1017 GDI-215: The use of MSG-MESH data cards is prohibited. A pu ...

Y R

SCM-1018 GDI-216: Structural and equipment masses: For the structura ...

Y R

SCM-1019 GDI-217: When necessary, equipments may be represented by C ...

Y R

3.2.4.6 FEM Checks SCM-1021 GDI-221:

The outputs of the NASTRAN “Grid Point Weight Gene ... Y A

SCM-1022 GDI-223: Strain energy and stiffness maxratio are requested ...

Y A

SCM-1023 GDI-225: The purpose of the conditioning check is to identi ...

Y A

SCM-1024 GDI-227: The purpose of the constraint check is to verify t ...

Y R

SCM-1025 GDI-229: The purpose of the "Free-Free" check is to verify ...

Y R

SCM-1026 GDI-231: The purpose of the static load check is to confirm ...

Y R

SCM-1027 GDI-233: The purpose of the "Zero" stress check is to verif ...

Y R

SCM-1028 GDI-235: Full finite element models shall be correlated wit ...

Y T,A

SCM-1119 GDI-2096: The difference between the Centre of Gravity posit ...

Y T,A

SCM-1029 GDI-2095: The mass difference between the measured and FEM f ...

Y T,A

SCM-1030 GDI-2074: If Reduced Distortion Analysis Models are requeste ...

Y T,I

SCM-1034 GDI-2067: The mass difference between the measured and FEM f ...

Y T,A

SCM-1033 GDI-2068: The difference between the Centre of Gravity posit ...

Y A,I

SCM-1032 GDI-2071: For other modes within the frequency range of inte ...

Y T,A

SCM-1031 GDI-2072: The Reduced Model Model delivery shall include the ...

Y A,R

LISA Pathfinder


Page 39 of 42




SCM-1035 GDI-2043: For gravitational modelling purposes, the mass dis ...

Y A,R

3.5.7 EMC Requirements 3.5.7.1 Bonding SCM-1036 GDI-562:

The bond shall be resistant against corrosion and ... Y R

SCM-1037 GDI-563: Metallic parts of each electrical equipment chassi ...

Y T

SCM-1038 GDI-564: Joint faces shall be flat and clean before assembl ...

Y I,R

SCM-1039 GDI-565: All non-electrical equipment shall be bonded to th ...

Y T

SCM-1040 GDI-566: Each electrical equipment chassis (case) shall be ...

Y T,R

SCM-1041 GDI-569: Electrical bonding throughout CFRP structure shall ...

Y R

SCM-1042 GDI-570: The resistance between any adjacent parts of the G ...

Y T,R

SCM-1043 GDI-571: The resistance between any point of the GRR shall ...

Y T,R

SCM-1044 GDI-578: Conducive struture components shall be electricall ...

Y I,R

SCM-1045 GDI-1990: The DC resistance between two mating metal strutur ...

Y T,R

SCM-1046 GDI-1991: Across moveable parts, a bond strap shall be appli ...

Y T,R

SCM-1047 GDI-1992: For CFRP structure without shielding function, the ...

Y T,R

SCM-1049 GDI-2092: For CFRP structure used for electromagnetic shield ...

Y T,R

SCM-1050 GDI-1989: Metal fittings shall be bonded to the structure wi ...

Y T,R

SCM-1051 GDI-579: Metal fittings shall be bonded to CFRP with a DC r ...

Y T,R

SCM-1052 GDI-2105: The DC resistance from any metal structure part an ...

Y T,R

SCM-1053 GDI-2094: The DC resistance between any other conductive com ...

Y T,R

SCM-1054 GDI-1993: The GRR shall be attached at less than or equal to ...

Y T,R

SCM-1055 GDI-1994: The resistance between any adjacent parts of the G ...

Y T,R

SCM-1056 GDI-1995: The resistance between any point of the GRR shall ...

Y T,R

SCM-1057 GDI-581: Mechanical Parts without electrical nor shielding ...

Y T,R

SCM-1058 GDI-582: Mechanical Parts used for electromagnetic shieldin ...

Y T,R

SCM-1059 GDI-586: CFRP and SiC shall not be used as an electrical bo ...

Y R

SCM-1060 GDI-593: Space exposed Insulating material having a bulk re ...

Y R

4 Environment Design Requirements 4.1 Atmospheric Conditions

LISA Pathfinder


Page 40 of 42




4.1.1 Humidity SCM-1064 GDI-771:

The unit shall be designed to withstand a relative ... Y R

4.1.2 Cleanliness SCM-1066 GDI-773:

The cleanliness design requirements on the unit H/ ... Y R

4.1.3 Storage time SCM-1068 GDI-775:

The S/C units flight H/W shall be designed to with ... Y R

4.1.4 Pressure Environment SCM-1070 GDI-780:

Units mounted on the S/C shall be designed to with ... Y T

4.1.5 Contamination SCM-1072 GDI-782:

Cleanliness requirements are as defined in the Sec ... Y T,R

SCM-1073 GDI-790: The equipment/assembly and associated transport co ...

Y T,A

SCM-1074 GDI-795: The design of transport containers shall be such t ...

Y T,A

SCM-1077 GDI-838: During transportation and storage, the spacecraft ...

Y R

4.5.11 DC Magnetic Requirements SCM-1079 GDI-954:

The use of ferro-magnetics shall be avoided for pa ... Y I,R

SCM-1080 GDI-956: Steel or other magnetic materials shall be avoided ...

Y I,R

5.1.1 Test Definition SCM-1081 GDI-967:

Qualification of the design shall be accomplished ... Y T,A

SCM-1082 GDI-969: Environmental acceptance testing shall be performe ...

Y T,A,R

SCM-1083 GDI-973: Any test facility to be used within the instrument ...

Y A,R

SCM-1084 GDI-975: The accuracy of instrument and test equipment used ...

Y A,R

SCM-1085 GDI-977: The allowed test condition tolerances shall be app ...

Y A,I,R

SCM-1086 GDI-981: Unless otherwise specified herein, all measurement ...

Y A,I,R

SCM-1087 GDI-983: Test execution shall be started only if all starti ...

Y A,I,R

SCM-1088 GDI-985: The test is successfully performed if all measurem ...

Y T,A

LISA Pathfinder


Page 41 of 42

Requirement/Section Cross Reference

SCM-297 .........5.2.4.1 SCM-168 .........3.5 SCM-57 ...........3.1 SCM-298 .........5.2.4.1 SCM-175 .........3.5 SCM-58 ...........3.1 SCM-299 .........5.2.4.1 SCM-176 .........3.5 SCM-75 ...........3.1.2 SCM-300 .........5.2.4.1 SCM-177 .........3.5 SCM-76 ...........3.1.2 SCM-301 .........5.2.4.1 SCM-178 .........3.5 SCM-83 ...........3.1.4 SCM-302 .........5.2.4.1 SCM-179 .........3.5 SCM-84 ...........3.1.4 SCM-316 .........5.3 SCM-180 .........3.5 SCM-86 ...........3.1.4 SCM-317 .........5.3 SCM-181 .........3.5 SCM-88 ...........3.1.4 SCM-478 .........3.5 SCM-182 .........3.5 SCM-89 ...........3.1.4 SCM-479 .........5.2.1 SCM-183 .........3.5 SCM-90 ...........3.1.4 SCM-484 .........4.3.1 SCM-184 .........3.5 SCM-91 ...........3.1.4 SCM-490 .........3.1 SCM-185 .........3.5 SCM-93 ...........3.1.4 SCM-494 .........3.1.4 SCM-186 .........3.5 SCM-94 ...........3.1.4 SCM-496 .........3.1.4 SCM-187 .........3.5 SCM-95 ...........3.1.4 SCM-504 .........3.1.4 SCM-189 .........3.5 SCM-96 ...........3.1.4 SCM-505 .........3.1.4 SCM-190 .........3.5 SCM-99 ...........3.1.4 SCM-506 .........3.1.4 SCM-191 .........3.5 SCM-101 .........3.1.4 SCM-507 .........3.1.5 SCM-196 .........4.1 SCM-102 .........3.1.4 SCM-510 .........3.5 SCM-199 .........4.2.1 SCM-103 .........3.1.4 SCM-514 .........4.3.1 SCM-200 .........4.2.1 SCM-104 .........3.1.4 SCM-519 .........5.2.2 SCM-204 .........4.2.2 SCM-105 .........3.1.4 SCM-735 .........4.3.1 SCM-206 .........4.2.3 SCM-106 .........3.1.4 SCM-736 .........4.3.1 SCM-211 .........4.2.4.1 SCM-107 .........3.1.4 SCM-1093 .......3.5 SCM-213 .........4.2.4.2 SCM-108 .........3.1.4 SCM-1097 .......4.3.1 SCM-215 .........4.2.5-1 SCM-110 .........3.1.4 SCM-1098 .......5.2.1 SCM-216 .........4.2.5-2 SCM-111 .........3.1.4 SCM-1099 .......5.3 SCM-219 .........4.3.1 SCM-113 .........3.1.4 SCM-1100 .......3.5 SCM-220 .........4.3.1 SCM-114 .........3.1.4 SCM-1101 .......3.1.4 SCM-221 .........4.3.1 SCM-116 .........3.1.4 SCM-1102 .......5.2.4 SCM-222 .........4.3.1 SCM-117 .........3.1.4 SCM-1103 .......4.3.1 SCM-224 .........4.3.1 SCM-118 .........3.1.4 SCM-1105 .......3.1.4 SCM-226 .........4.3.1 SCM-119 .........3.1.4 SCM-1124 .......3.1 SCM-228 .........4.3.1 SCM-121 .........3.1.4 SCM-1125 .......3.1 SCM-229 .........4.3.1 SCM-122 .........3.1.4 SCM-1126 .......3.1 SCM-231 .........4.3.1 SCM-123 .........3.1.4 SCM-1127 .......3.1 SCM-244 .........4.3.1 SCM-124 .........3.1.4 SCM-1128 .......3.1.4 SCM-246 .........4.3.1 SCM-126 .........3.1.5 SCM-1130 .......3.1.4 SCM-250 .........4.3.1 SCM-129 .........3.2 SCM-1132 .......5.2.4 SCM-251 .........4.3.1 SCM-131 .........3.2.1 SCM-252 .........4.3.1 SCM-133 .........3.2.2

SCM-253 .........4.3.1 SCM-135 .........3.2.2 SCM-258 .........4.3.2.1 SCM-138 .........3.3.1 SCM-259 .........4.3.2.1 SCM-139 .........3.3.1 SCM-260 .........4.3.2.1 SCM-140 .........3.3.1 SCM-261 .........4.3.2.1 SCM-141 .........3.3.1 SCM-262 .........4.3.2.1 SCM-142 .........3.3.1 SCM-267 .........4.3.3 SCM-143 .........3.3.1 SCM-271 .........5.1.1-1 SCM-145 .........3.3.2 SCM-273 .........5.2 SCM-147 .........3.3.2 SCM-274 .........5.2 SCM-149 .........3.4 SCM-276 .........5.2.1 SCM-157 .........3.4 SCM-277 .........5.2.1 SCM-158 .........3.4 SCM-280 .........5.2.2 SCM-159 .........3.4 SCM-282 .........5.2.2 SCM-160 .........3.4 SCM-284 .........5.2.3 SCM-161 .........3.4 SCM-286 .........5.2.4 SCM-164 .........3.5 SCM-295 .........5.2.4.1 SCM-165 .........3.5 SCM-296 .........5.2.4.1 SCM-167 .........3.5

Document Autogenerated from DOORS Module : /LISA Pathfinder/Level 3/Mechanical/SCM/SCM Structure S2.ASU.RS.2006 Issue 1.doc

LISA Pathfinder


Page 42 of 42

DOCUMENT CHANGE DETAILS

ISSUE CHANGE AUTHORITY CLASS RELEVANT INFORMATION/INSTRUCTIONS

A - - Initial Issue For Draft SCM Structure ITT

1 - - First Formal Issue

DISTRIBUTION LIST

INTERNAL

EXTERNAL

G. Adams R. Grünagel, Estec, ESA N. Dunbar A.G. Jones P. Kemp M. Stewart K. Tomkins Configuration Management

Document Autogenerated from DOORS Module : /LISA Pathfinder/Level 3/Mechanical/SCM/SCM Structure S2.ASU.RS.2006 Issue 1.doc