s5p sp asu sc 00002 mli requirements specification iss...

S5P.SP.ASU.SC.00002SSp Issue 01 of 28

ASTRIUM

MLI REQUIREMENTS SPECIFlCATION

CI CODE: 5123000 DRL Refs:

UK EXPORT CONTROL RATING: Not Listed Rated By : J BanUng

:Prepared by: - ~A\j QJcvk=--____ __ Date:

R. Rolston

:Checked by: ___dLg_~~~ ___________ J Banting

Dale: _lfLt/@\,_._____________

Approved by:: Dale. 2.2/¢2__ M Sharples

:Authorised by: Date:

© Astrium Limited 2012

Astrium Lid 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.

Astrium Limited, Registered in England and Wales No_ 2449259 Registered Office : Gunnels Wood Road, Stevenage, Hertfordshire, SG1 2AS, England

Document Autogenerated from DOORS Module: IS5p1level 3IThermai Hardware SSP.SP.ASU.SC.00002_Mll_Requirements_SpecificaUofUss_1 .doc

S5p S5P.SP.ASU.SC.00002

Issue 01 of 28

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.

S5P SP ASU SC 00002_MLI_Requirements_Specification_Iss_1.doc

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CONTENTS 1 INTRODUCTION AND SCOPE................................................................................................................. 7

1.1 SCOPE............................................................................................................................................... 7 1.2 GUIDELINES ..................................................................................................................................... 7

2 APPLICABLE DOCUMENTS AND REFERENCES.................................................................................. 8 2.1 APPLICABLE DOCUMENTS............................................................................................................. 8 2.2 REFERENCE DOCUMENTS............................................................................................................. 8

3 ACRONYMS.............................................................................................................................................. 9 4 SYSTEM DESCRIPTION AND DEFINITIONS ....................................................................................... 10

4.1 SATELLITE CONFIGURATION....................................................................................................... 10 4.2 COORDINATE SYSTEMS............................................................................................................... 12

5 SUBSYSTEM FUNCTION AND INTERFACES...................................................................................... 15 5.1 SUBSYSTEM DEFINITION.............................................................................................................. 15 5.2 ENVIRONMENTAL CONDITIONS .................................................................................................. 17 5.3 FUNCTIONAL REQUIREMENTS .................................................................................................... 18 5.4 INTERFACES .................................................................................................................................. 19

5.4.1 Mechanical and Thermal Interfaces to Payloads...................................................................... 19 5.4.2 Mechanical and Thermal Interfaces to Platform Subsystems .................................................. 19

6 REQUIREMENTS.................................................................................................................................... 20 6.1 PHYSICAL REQUIREMENTS ......................................................................................................... 20

6.1.1 Mass limit .................................................................................................................................. 20 6.1.2 Dimensional Limitations Dismountability and Accessibility....................................................... 20 6.1.3 Durability Factors ...................................................................................................................... 21 6.1.4 Interfaces .................................................................................................................................. 21

6.2 PERFORMANCE REQUIREMENTS ............................................................................................... 21 6.2.1 Thermal Performance ............................................................................................................... 21 6.2.2 Temperature Range.................................................................................................................. 22 6.2.3 Life-time .................................................................................................................................... 23

7 DESIGN AND CONSTRUCTION............................................................................................................ 24 7.1 MECHANICAL DESIGN................................................................................................................... 24

7.1.1 Stand-off or Velcro Attachments............................................................................................... 24 7.1.2 Adhesive Transfer Tape Attachment ........................................................................................ 25 7.1.3 Adhesive Kapton Tape Attachment .......................................................................................... 25

7.2 Bending ............................................................................................................................................ 25 7.3 Overlap............................................................................................................................................. 25 7.4 Crack Stoppers ................................................................................................................................ 26 7.5 ELECTRICAL DESIGN .................................................................................................................... 26 7.6 VENTING ......................................................................................................................................... 26 7.7 FLEXIBILITY .................................................................................................................................... 27 7.8 ACCESSIBILITY/MAINTAINABILITY............................................................................................... 27 7.9 INTERCHANGEABILITY.................................................................................................................. 27 7.10 MAINTENANCE ........................................................................................................................... 27 7.11 CLEANLINESS............................................................................................................................. 28 7.12 SAFETY........................................................................................................................................ 28 7.13 PARTS, MATERIALS AND PROCCESSESS.............................................................................. 28 7.14 HARDWARE HANDLING, MARKING, TRANSPORTATION AND STORAGE ........................... 28

7.14.1 Preparation for delivery and storage......................................................................................... 28 7.14.2 Storage ..................................................................................................................................... 29 7.14.3 Product identification and marking............................................................................................ 29 7.14.4 Transport requirements............................................................................................................. 29 7.14.5 Shipping container requirements .............................................................................................. 30 7.14.6 Ground Support Equipment general requirements................................................................... 30

8 VERIFICATION ....................................................................................................................................... 31 8.1 VERIFICATION BY ANALYSIS ....................................................................................................... 31 8.2 VERIFICATION BY TEST................................................................................................................ 31

9 QUALITY ASSURANCE PROVISSIONS................................................................................................ 32

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1 INTRODUCTION AND SCOPE

1.1 SCOPE

The document specifies the contractually relevant requirements as well as assumptions and constraints, which apply to the development, design, manufacturing, assembly, verification and delivery of the S5p Platform Thermal Control Subsystem.

In the case of conflicts, this specification supersedes [AD.1]. The conflict shall be reported to the Platform prime.

1.2 GUIDELINES

Requirements within this document are shown in an italic font. Each requirement is preceded by a summary line that contains the following fields, delimited by "/".

Requirement Number

Intended Verification Method

The Requirement Number has the form TH-xxx where xxx is a unique number assigned consecutively.

The Intended Verification Method codes are as follows:

R - Review

A - Analysis

I - Inspection

T - Test

S-Similarity

The requirement text follows the summary line. If tables are considered as part of requirement they are referenced clearly in the text and inserted after and separated from the requirement and are managed as free text attached to the identifier requirement.

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

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2 APPLICABLE DOCUMENTS AND REFERENCES

2.1 APPLICABLE DOCUMENTS

# REFERENCE DOCUMENT ISSUE

AD.1 DIV.SOW.00027.T.ASTR AS250 Equipment GDIR 03 AD.2 S5P.SP.ASU.SAT.00016 Environmental and Test

Requirements Specification 02

AD.3 S5P.IRD.ASU.SC.00005 MLI IRD 01 AD.4 NOT USED AD.5 NOT USED AD.6 S5P.SP.ASU.SY.00010 Product Assurance Requirements

for Subcontractors - Space Segment

02

AD.7 S5P.SP.ASU.SY.00021 Cleanliness Requirement Specification

04

AD.8 ECSS-E-ST-31C Space Engineering -Thermal Control General Requirements

02

2.2 REFERENCE DOCUMENTS

# REFERENCE DOCUMENT ISSUE

RD.1 S5P.LIS.ASU.SY.00001 Directory of Acronyms and Abbreviations

01

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3 ACRONYMS

See [RD.1] [139]

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4 SYSTEM DESCRIPTION AND DEFINITIONS

The Sentinel-5 Precursor mission is being proposed to ensure a continuous data stream in measuring elements relevant to atmospheric chemistry at high temporal and spatial resolution. The gases include ozone, NO2, SO2, BrO, formaldehyde and aerosols. A Sentinel-5 Precursor mission is planned to launch in 2014, to avoid data gaps between Envisat (Sciamachy data in particular) and Sentinel-5. This mission will be devoted to atmospheric monitoring.

Sentinel-5 Precursor will observe the atmosphere primarily in the UV and visible, and its operation is therefore constraint by the solar illumination conditions of the scene, where the Sun Zenith Angle must be less than 92 (TBC). This means that TROPOMI makes observations of the atmosphere from pole to pole, on the sunlit face of the Earth. On the dark side of the Earth, it performs various calibration observations (of the Earth or of onboard light sources) to ensure a good knowledge of the spectral response of the detectors. There are also calibration observations of the Sun once a day near the North Pole through a diffuser on a dedicated port.

The S5p orbit is a sun-synchronous orbit at a mean altitude of 824 km, providing a 17-day repeat cycle, with an LTAN of 13:35.

4.1 SATELLITE CONFIGURATION

The Sentinel-5 Precursor Platform mechanical configuration is based on an hexagonal prism including a transition structure to provide the required geometrical evolution to the circular interface of the launcher.

The internal cavity of the prism permits the accommodation of the Propulsion module which is located on the lower basis of the prism, with the Primary Payload accommodated on the top side of the prism. The Solar Array Panels are arranged around three lateral sides of the hexagon. Figure 4.1-1 shows the S/C components in an exploded view.

Two configurations of the satellite are achievable in flight, as shown in figure 4.1-2:

Launch configuration, with the Solar Array in stowed position.

Orbital configuration, with all the elements being deployed .

The proposed mechanical architecture is compliant with a modular concept which enables as much as possible a partial and separated integration of the different subassemblies. The lateral panels can be rotated during the integration phases to ease the installation of the units and harness.

Figure 4.1-1: Satellite Configuration. Components Exploded View

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Figure 4.1-2 Satellite Configurations

4.2 COORDINATE SYSTEMS

The reference frames to be used for the project are defined in [AD.2].

The Satellite Reference Frame is presented in Figure 4.2-1. The origin of the Satellite Reference Frame (XS, YS, ZS) is at the interface plane separating the satellite and the launcher, at the centre of the adaptor as

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shown in Figure 4.2-1. The system is fixed to the S/C and invariant for both stowed and deployed configurations.

The axes are defined as follow:

The ZS axis is normal to the launcher interface plane, towards the body of the satellite;

The YS axis points towards a solar panel. For ease, the deep space wall is taken as –YS.

The XS axis completes a right-handed orthogonal set. It results that +XS is pointing in the opposite direction to the velocity vector.

Z

X

Y

V

V

Y

X

Z

Z

Y X

Figure 4.2-1 Sentinel-5 Precursor Satellite Reference Frame.

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Figure 4.2-2 Sentinel-5 Precursor Orbital Reference Frame.

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5 SUBSYSTEM FUNCTION AND INTERFACES

5.1 SUBSYSTEM DEFINITION

The main features of the Sentinel-5 Precursor Platform Thermal Control, shown in Figure 5.2-1.are:

A global control concept, suitable for the majority of the equipment on the Platform enclosure, based on:

high emissivity coatings for structural parts and equipment housings to enhance radiative heat exchanges

doublers to spread heat from the high power density equipment and/or to improve the conductive coupling between some of the units

radiators under the most dissipative equipment for heat rejection.

heater lines controlled by thermistors for those units which temperature range can not be kept using only passive means.

Each, the Battery and the Propulsion module, require an specific thermal control, based on:

low emissivity coatings or blankets to provide radiative isolation from the enclosure;

dedicated heater lines controlled by thermistors.

Etched foil electrical resistance heaters, installed on thermal doublers and equipment, as required are used for the heater system to control the equipment temperature in any Satellite mode.

S-Band Transponders

OBC

PCDU

ICU

Mass Memory

X-Band

Battery1

Battery2

RIU

STRElectronics

S-Band Transponders

OBC

PCDU

ICU

Mass Memory

X-Band

Battery1

Battery2

RIU

STRElectronics

Figure 5.1-1 Sentinel-5 Precursor Platform Internal Equipment

The Platform Thermal Control is defined to maintain all the Platform equipment within applicable temperature range, during the complete mission lifetime, starting from lift-off. It is based in a mainly passive design supported by heater systems.

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All THW is to be able to withstand all the nominal thermal environments encountered during its entire lifetime, whilst meeting all performance requirements relevant to the specific phases outlined below:

Integration, transportation, testing, and storage.

Spacecraft preparation at the launch site,

Pre-launch phase with the spacecraft encapsulated in the launch vehicle,

Ascent phase

In-orbit operation phase from launcher separation until the end of the extended mission.

Safe Mode

5.2 ENVIRONMENTAL CONDITIONS

TH-220 / / T,A,R

The Platform MLI shall be defined to meet the specified performance requirements under the environmental conditions defined in [AD.1].

The range of thermal environment parameters in orbit are presented Table 5.2-1:

Parameter Min Max Solar flux constant [W/m^2] 1321 / 0.0 (eclipse) 1423 / 0.0 (eclipse)

Earth temperature [K] 244 264 Albedo[] 0.25 0.35

Table 5.2-1 Thermal Environment Parameters Table

TH-491 / / A,R

The orbit parameters, S/C configuration parameters, Platform configuration parameters and orbital environment defined in [AD.1],[AD.2], [AD.3], shall be taken into account to define the external loads (sun, earth and albedo radiation, depressurization, ATOX fluence) and the external radiative heat exchanges. The orbit altitude is approximately 830 km as defined in [AD-2].

TH-492 / / A

The Thermal Blanket subcontractor shall design each unit to cope with the worst-case thermal fluxes during launch and ascent as defined in (AD4). Under fairing

Duration: 3 min (TBC) Direction on any surface of the satellite Flux < 800 W/m2 (TBC)

After fairing jettison (aerothermal) Direction: perpendicular to velocity vector (TBC) Duration 20 s (TBC) Flux < 1135 W/m2 (TBC)

Until S/C separation (aerothermal) (TBC) Direction: perpendicular to velocity vector (TBC) Duration TBD Flux < TBD W/m2

After S/C separation and before S/C acquisition Direction any

Duration up to 4 hours (TBC) Flux Solar + Earth albedo + Earth infrared radiations

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5.3 FUNCTIONAL REQUIREMENTS

The S/C FM thermal blanket configuration to be supplied contains all the thermal blanket (FM and spare) necessary for the S5P S/C.

TH-395 / / R

The S/C Thermal Blanket configuration shall comply to the interfaces defined in AD-3.

TH-401 / / R

The flight S/C Thermal Blanket shall comprise of the items listed in AD-3.

TH-409 / / R

Final numbers of blankets shall be approved by the prime contractor.

Number of Blankets. As a goal the number of blankets shall be minimised.

TH-402 / / T,A,R

The Thermal Blanket subcontractor shall be responsible for the MLI construction, including definition of materials and associated fixation hardware to the structure.

TH-411 / / A,R

The design MLI shall be carried out in order to avoid any holes or unprotected part that can introduce in the S/C heat balance and additional heat source (Sun trapping effect).

TH-410 / / R

The location of fixations shall be defined by the supplier with respect to the interface, environment and performance requirements in agreement with the prime contractor.

TH-412 / / R

The design of the MLI must allow 10mm for the height of harness bundles & bolt heads not represented in the spacecraft interface definition.

TH-403 / / R

The Thermal Blanket subcontractor shall be responsible for the definition of attachment devices for grounding.

TH-404 / / R

The Thermal Blanket subcontractor shall be responsible for the definition of adhesive tapes for overlap (if any).

TH-405 / / I,R

The Thermal Blanket subcontractor shall be responsible for the manufacturing and delivering of the thermal blankets and thermal blankets templates in accordance with thermal interface control drawings and defined access to the spacecraft for tailoring of blanket configuration.

5.4 INTERFACES

5.4.1 Mechanical and Thermal Interfaces to Payloads

TH-226 / / T,A,R

Primary Payload. The MLI interfaces to Primary Payload (PP) shall comply with the interface requirements detailed in AD.3.

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5.4.2 Mechanical and Thermal Interfaces to Platform Subsystems

TH-232 / / T,A,R

Platform Subsystems and Equipment. The MLI interfaces to Platform Subsystems (Structure, Harness SA, Propulsion Module, Avionics, X and S Band Communication subsystems…) shall comply with the interface requirements detailed in [AD.3].

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6 REQUIREMENTS

6.1 PHYSICAL REQUIREMENTS

6.1.1 Mass limit

TH-245 / / T,A,R

Mass. The mass of the Platform MLI hardware shall be minimised, it shall not exceed 10 Kg (TBC).

TH-406 / / T,A

The MLI mass shall include all electrical grounding hardware, blanket attachment hardware and any extra coating applied on outer layer.

TH-407 / / T

Each S/C thermal blanket item shall be weighed individually.

TH-246 / / A,R

Mass Margins. The MLI mass budget to be compared with TH-245 shall include all possible margin associated to hardware design uncertainties and maturity [AD-1].

TH-248 / / T,R

Mass Measurement. The Platform MLI mass shall be measured with an accuracy of at least 50g.

6.1.2 Dimensional Limitations Dismountability and Accessibility

TH-250 / / I,R

Dismountability. The following components shall be dismountable:MLI blankets, foils (SLIs).

TH-252 / / I,R

Accessibility. The thermal control hardware shall be designed to allow unrestricted access to all connectors, umbilical connectors, alignment devices, major mounting interfaces, AIT interfaces and to allow the replacement of critical units or subsystem assemblies.

TH-253 / / I,R

Degradation by Removal. All TC S/S components for which dismountability is required during integration and verification (e.g. blankets, interface fillers) shall be designed such as to be removed/reinstalled without degradation of thermal performances. Otherwise, substitution of the removed hardware part shall be agreed in a case by case basis.

TH-254 / / I,R,S

MLI removals. For blankets, the number of removals shall be at least ten times prior to replacement by spares.

6.1.3 Durability Factors

TH-256 / / I,R

Care shall be taken during all handling operations to ensure that thermal finishes and insulation blankets are not degraded. Protective covers as required shall be provided and handling procedures specified where necessary.

6.1.4 Interfaces

TH-258 / / T,I,R

The TC S/S shall be compatible with the interfaces defined in section 5.4. In particular, the thermal blankets design shall allow:

deployment and latching of the Solar Array Panels

interface with Payloads and Launcher

interface to MGSE

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6.2 PERFORMANCE REQUIREMENTS

6.2.1 Thermal Performance

The thermal efficiency of MLI is defined as a radiative efficiency (Er) and a conductive efficiency (Ec). So MLI leaks are defined as follow:

Q = Ec x S x T + Er x x S x T4

With T = Te - Ti

(Te is temperature of external sheet of MLI, Ti is temperature of the underlying surface)

S is surface of MLI

= 5.67 x 10e-8 (constant of Stephan-Boltzmann)

T4 = Te4 - Ti4

TH-416 / / I,R

The radiative efficiency of the spacecraft internal MLI and the spacecraft external MLI covering the spacecraft ±X±Y, ±Y and +Z panels shall be ≤ 0.014 m2/m2.

The conductive efficiency of the spacecraft internal MLI and the spacecraft external MLI covering the spacecraft ±X±Y, ±Y and +Z panels shall be ≤ 0.019 W/Km2.

The radiative efficiency of the spacecraft internal MLI and the spacecraft external MLI covering

the spacecraft -Z panels shall be ≤ 0.007m2/m2.

The conductive efficiency of the spacecraft internal MLI and the spacecraft external MLI

covering the spacecraft -Z panels shall be ≤ 0.0095W/Km2.

TH-417 / / T

The supplier shall demonstrate the MLI efficiency by test. Analysis or similarity of MLI performance from previous experience may be acceptable but shall be justified. Applicability of similarity shall be approved by Astrium.

TH-418 / / T,A,R

The blanket materials shall meet the performance requirements over the life of the spacecraft.

TH-419 / / T,R

The S/C thermal hardware coatings shall be designed such that performance, as measured at ambient conditions on ground, are maintained in the space environment.

TH-420 / / T,R

The thermo-optical properties of the external surface of the spacecraft external blankets shall have an emissivity of 0.75 +/-0.05 and an absorptivity 0.4 +/-0.05.(BOL) / 0.5+/-0.05 (EOL).

TH-421 / / T,R

The thermo-optical properties of the external surface of the spacecraft internal blankets shall have an emissivity of 0.05 +/-0.02. (TBC)

The supplier can propose different MLI materials in order to achieve the optimal thermal performance.

TH-422 / / R

The supplier shall identify the materials degradation effect to the optical property due to exposure to the mission's external orbital environment.

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TH-424 / / A,R

The supplier shall provide the exact designation of MLI materials and their properties (properties shall at least contain asborptance, emissivity and specularity at beginning and end of life).

TH-425 / / A,R

Particular attention shall be paid to the selection of the materials and processes to avoid sensitivity of these coatings to water desorption in vacuum environment, especially for the multi layer coatings, if any.

6.2.2 Temperature Range

TH-428 / / T,A,R

All S/C external blankets (panel and equipment specific) shall withstand without degradations of their thermal and mechanical properties (MLI efficiency, thermo-optical values...) the operating temperature range for the outer layer of -180ºC to +180ºC.

TH-429 / / T,A,R

The S/C internal blankets shall withstand without degradations of their thermal and mechanical properties (MLI efficiency, thermo-optical values) the operating temperature range of -40ºC to +60ºC.

TH-430 / / T,A,R

The stand-off/Velcro shall be bonded on Al substrate with a min/max qualification temperature of -90/+90degC.

TH-431 / / A,R

The S/C thermal hardware blankets shall be sized so that they will not be stressed (tensile or compression) by their fixation points, taken into account the thermal environment (including space conditioning).

6.2.3 Life-time

TH-267 / / A,R

The MLI shall be designed and sized to meet the temperature control requirements during the nominal life of 7 years in orbit.

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7 DESIGN AND CONSTRUCTION

7.1 MECHANICAL DESIGN

TH-295 / / T,A,R

Mechanical Design Requirements. The MLI blankets, as well as structural components supporting thermal control hardware, shall be designed to withstand the acoustic environment given in [AD.2] without degradation.

The thermal blankets shall be attached to the spacecraft using any of the following four methods:

stand-offs

Velcro

adhesive transfer tape

adhesive Kapton tape

The design requirements for each of the fixing methods are given below.

7.1.1 Stand-off or Velcro Attachments

TH-434 / / R

The maximum distance between two attachments shall be less than 300mm.

TH-435 / / R

Attachments shall be indicated in the blanket manufacturing files.

TH-436 / / R

Fixing points along the edge of a blanket shall be between 20mm and 100mm from the edge, and no more than 300mm apart.

TH-437 / / R

Fixing points shall not be positioned closer than 20mm to any slit, cut-out, corner or grounding position.

TH-438 / / R

Methods for attachment of stand-offs to Aluminium structure to be identified by thermal blanket supplier. The thermal blanket supplier shall provide evidence of the attached method for each application.

TH-439 / / R

The adhesive / material combinations shall withstand temperature ranges as given in Section 6.2.2.

TH-440 / / R

Location of stand-offs shall be defined in accordance with the prime contractor. The subcontractor shall confirm layout with prime contractor. Note that stand-offs must avoid the location of structure grounding straps.

7.1.2 Adhesive Transfer Tape Attachment

TH-442 / / R

If adhesive transfer tape is used to attach blankets, the tape shall be 3M 966).

TH-443 / / R

Adhesive transfer tape shall not be the sole means of securing a blanket.

TH-444 / / R

25mm by 25mm patches of adhesive shall be used to secure areas of blankets to the spacecraft, arranged in a 200mm square grid.

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TH-446 / / R

Where this method is used to secure the edges of blankets, 25mm wide strips of adhesive shall be used. A gap of 25mm shall be left every 300mm to allow venting.

TH-445 / / R

Fixings made using adhesive transfer tape are not intended to be disassembled. If for any reason a blanket fixed by this method is removed, a new piece of transfer adhesive shall be applied to cover all traces of the old adhesive. The backing paper shall not be removed until just before the blanket is re-attached to the spacecraft.

7.1.3 Adhesive Kapton Tape Attachment

TH-450 / / R

Kapton tapes shall only be used at the edge of a blanket for blanket to blanket joints, or for sealing the edge of a blanket to the structure.

TH-451 / / R

The tape chosen for each individual joint shall match the thermo-optical properties of the adjacent blankets.

TH-452 / / R

The minimum tape width used shall be 25mm.

7.2 Bending

TH-458 / / R

Blankets which bend over edges have to be built in such a way that compression at the edges and resulting increased heat links shall be estimated and minimised.

7.3 Overlap

TH-460 / / R

Internal and external blankets shall overlap adjacent blankets by at least 50mm.

TH-461 / / R

The edges of MLI blankets shall be sealed.

TH-462 / / R

The outer layer of a blanket shall overlap the inner layer by at least 25mm where it is wrapped over at the edge of the blanket.

7.4 Crack Stoppers

TH-464 / / R

All slits and cut-outs on the blankets shall be protected against tearing by finishing with a hole of 3mm (+ 2mm tolerance) diameter.

7.5 ELECTRICAL DESIGN

TH-297 / / R

External Surfaces Electrical Conductivity. The use of space exposed insulating materials having a surface resistivity higher than 109 Ω /square or having a bulk resistivity higher than 1012 Ω m shall reported to the Prime for approval.

TH-298 / / I,R

Foils and Tapes Grounding. All foils (i.e. SLIs and MLIs) and tapes with metallic layers shall be grounded. Grounding points on S/C side will be provided by Electrical or Structure Subsystem.

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TH-299 / / I,R

MLI Grounding Points. The MLI grounding points shall be in a minimum of 2 locations (opposite corners), such that no piece of blanket is further than 1m away from one grounding point. No blanket shall exceed 2 m2 in size, each blanket shall be individually grounded to the structure. For small MLI pieces, below 0.01m2, grounding at one point is sufficient.

TH-300 / / T

MLI Grounding Resistance. The resistance between each MLI grounding point and the structure shall be lower than 1Ω.

TH-301 / / T

Internal MLI Resistance. The resistance between each MLI grounding point and each point of a conductive layer shall be lower than 100Ω.

7.6 VENTING

TH-306 / / T,A,R

Venting. Venting provisions shall be taken for all MLI blankets. Venting provisions shall allow adequate depressurisation through launch and ascent. The static pressure evolution during this period is specified in [AD.2].

TH-453 / / A,R

The S/C thermal blanket shall ensure adequate venting of volumes enclosed by them to accommodate the rate of barometric pressure during launch, ascent and test

TH-454 / / I,R

The S/C thermal blanket shall avoid contamination (in particular on mirrors) by particles from inside blanket during venting.

TH-455 / / I,R

Adjacent blanket layers shall be configured so that the perforations do not line up.

TH-456 / / R

Justification of the size and pattern of the perforations of layers shall be provided.

7.7 FLEXIBILITY

TH-309 / / R

Trimming. The thermal design shall allow trimming of temperature levels and radiator sizes after PFM TB test correlation. Areas required for trimming are identified in AD.8

7.8 ACCESSIBILITY/MAINTAINABILITY

TH-466 / / R

The S/C thermal blankets shall be removable. It shall be designed to facilitate the maintenance, mounting and dismounting operations, element inspections and replacement of failed elements by a good accessibility.

TH-467 / / I,R

The S/C thermal blankets shall be designed such that they may be easily removed from and replaced ten times on the spacecraft while maintaining reproducible mechanical and thermal characteristics (efficiency, thermo-optical properties...). If applicable, special care shall be taken for the blankets that use as external layer ITO coating for external surface electrical conductivity.

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7.9 INTERCHANGEABILITY

TH-311 / / I,R

Interchangeability. Each equipment item shall be directly interchangeable in form, fit and function with other equipment of the same identification. The performance characteristics and dimensions of equivalent items shall be uniform enough within the specified tolerances as to allow equipment interchange. The interchanged items must be of the same qualification and reliability status. See also [AD.1]

7.10 MAINTENANCE

TH-313 / / R

Maintenance. The maintenance requirements specified in [AD.1] shall be met.

7.11 CLEANLINESS

TH-315 / / R

Cleanliness Design Guidelines. The material selection criteria as stated in [AD.7] shall apply. The completed thermal blankets shall be subjected to bake out as defined in [AD.6].

7.12 SAFETY

TH-317 / / R

Safety. The safety requirements specified in [AD.6] shall be met.

7.13 PARTS, MATERIALS AND PROCCESSESS

TH-320 / / T,R

Material Properties. All materials shall be capable of operating satisfactorily for at least seven years in orbit after up to two years of ground storage. The surface finishes chosen shall be clearly defined. The following material properties shall be either adopted by similarity from previous applications or determined by measurement:

Hemispherical emittance

Solar Absortance

Out-gassing rates

Degradation of solar absortance and hemispherical emittance for a life-time of seven years in the relevant environment, as specified in [AD.2].

TH-321 / / R

PA Provisions. Product assurance during fabrication, integration, testing, handling and transportation shall be in accordance with the requirements in [AD.6].

7.14 HARDWARE HANDLING, MARKING, TRANSPORTATION AND STORAGE

7.14.1 Preparation for delivery and storage

TH-332 / / R

The Subcontractor shall describe in detail (either within the P.A. Plan or within the specific S/S PHTSI procedure) the means and policy they will apply for the preparation for delivery and storage for the S/S hardware. The Subcontractor is responsible for drafting and implementing the procedures related to the protection of items that are entrusted to him. Dedicated procedures and/or specific instructions shall be established within the S/S PHTSI Procedure, as far as necessary.

TH-333 / / I,R

All deliverable units and items shall be double bagged. Internal layer in contact with the unit shall be of a verified clean material (such as Kapton, Mylar...) sealed or taped, and the external layer shall act as a moisture barrier. If any, temporary covers and protections installed in the deliverable H/W shall be clearly identified by properly identified ("remove before flight") and coloured (red) labels, and also

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dedicated instructions for when removing them shall be established within the S/S PHTSI Procedure Desiccants shall not be in contact with the hardware, to prevent any massive particulate contamination of the hardware in case of breakage of the desiccant envelope.

TH-334 / / R

In any case, material used for bagging/packaging will be free of electrostatic charge in case of hardware inside were sensible on it, and also it will be free of potential contaminants.

7.14.2 Storage

TH-326 / / R

During manufacturing, the following procedure shall be used to store either fully or partially completed blankets within the confines of the blanket manufacturing area:

- Place each blanket, lying flat, into the storage area, and cover it with Mylar foil

- Up to 10 blankets may be stacked in this manner.

TH-470 / / R

After manufacturing, the S/C thermal blankets shall be stored using the following procedure:

- Wrap each blanket in clean, clear Mylar foil

- Seal up to 5 wrapped blankets in a polyethylene bag with a humidity indicator, and seal a label in a separate compartment

- Seal the first bag inside a second bag, with desiccant

- Pack the bag in a storage or transport container or sufficient strength and rigidity to prevent damage to the item under normal handling conditions

7.14.3 Product identification and marking

TH-328 / / I,R

Any deliverable Subsystem unit or item shall be properly identified, taking into account the considerations reflected in [AD.6]. Identification shall include as minimum CI number, model, serial number and top assembly drawing reference.

7.14.4 Transport requirements

TH-330 / / R

The deliverable unit/subset/assembly for this Subsystem shall be compatible with road/air transportation rules.

TH-471 / / R

S/C thermal blanket items shall be individually packed as described in Section 7.14.2.

TH-472 / / R

Where a purpose built container exists, the blankets shall be placed within it such that movement between blankets will be minimised.

7.14.5 Shipping container requirements

TH-336 / / I,R

Hard containers shall be used as an external envelope for storage / transportation. Provisions to avoid hardware shocks from transport shall be implemented in the shipping containers when necessary. If it is considered necessary, internal foam cut of unit size for shock protection can be used. In case of air transport, containers shall include also pressure monitors, and it shall comply with IATA regulations for pressurised or non-pressurised containers. Shipping containers shall be properly identified externally. Identification shall include as minimum Project name, Subsystem/Item, and CI number for the container.

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7.14.6 Ground Support Equipment general requirements

TH-340 / / I,R

General requirements for Ground Support Equipment (MGSE/EGSE), like transport container, handling devices, storage devices, GSE devices... shall be in accordance with the Sentinel-5 Precursor applicable GSE Requirement Specifications.

TH-341 / / I,R

GSE shall be properly identified. Identification shall include as minimum Project name, Subsystem/Item, and CI number for the GSE. When applicable, indications of proof test performed and maximum supported loads shall be included as a part of the GSE identification.

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8 VERIFICATION

8.1 VERIFICATION BY ANALYSIS

TH-469 / / R

No thermal model of the thermal hardware shall be provided to the prime contractor. However, sufficient data shall be provided through MICD and TICD in order to establish the system level mathematical model. These data shall be as a minimum:

- IR emissivity and solar absorptivity of external foils (at beginning and end of life)

- Blanket surfaces

- Mass

- Temperature limit

- Radiative and conductive efficiencies and their variation with the temperature range of work for MLIs

8.2 VERIFICATION BY TEST

TH-374 / / T,R

The hardware integrity and coatings integrity/degradation of the platform MLI shall be verified before and after the spacecraft system environmental test programme.

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9 QUALITY ASSURANCE PROVISSIONS

TH-379 / / T,A,R

Compliance with Product Assurance Requirements. All items of the subsystem shall be constructed, inspected and tested in accordance with the project product assurance requirements in [AD.6].

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Requirement/Section Cross Reference Page numbers are the pages where the sections start

TH-220 ............... 5.2....................17 TH-226 ............... 5.4.1.................19 TH-232 ............... 5.4.2.................19 TH-245 ............... 6.1.1.................20 TH-246 ............... 6.1.1.................20 TH-248 ............... 6.1.1.................20 TH-250 ............... 6.1.2.................20 TH-252 ............... 6.1.2.................20 TH-253 ............... 6.1.2.................20 TH-254 ............... 6.1.2.................20 TH-256 ............... 6.1.3.................21 TH-258 ............... 6.1.4.................21 TH-267 ............... 6.2.3.................23 TH-295 ............... 7.1....................24 TH-297 ............... 7.5....................26 TH-298 ............... 7.5....................26 TH-299 ............... 7.5....................26 TH-300 ............... 7.5....................26 TH-301 ............... 7.5....................26 TH-306 ............... 7.6....................26 TH-309 ............... 7.7....................27 TH-311 ............... 7.9....................27 TH-313 ............... 7.10..................27 TH-315 ............... 7.11..................28 TH-317 ............... 7.12..................28 TH-320 ............... 7.13..................28 TH-321 ............... 7.13..................28 TH-326 ............... 7.14.2...............29 TH-328 ............... 7.14.3...............29 TH-330 ............... 7.14.4...............29 TH-332 ............... 7.14.1...............28 TH-333 ............... 7.14.1...............28 TH-334 ............... 7.14.1...............28 TH-336 ............... 7.14.5...............30 TH-340 ............... 7.14.6...............30 TH-341 ............... 7.14.6...............30 TH-374 ............... 8.2....................31 TH-379 ............... 9.......................32 TH-395 ............... 5.3....................18 TH-401 ............... 5.3....................18 TH-402 ............... 5.3....................18 TH-403 ............... 5.3....................18 TH-404 ............... 5.3....................18 TH-405 ............... 5.3....................18 TH-406 ............... 6.1.1.................20 TH-407 ............... 6.1.1.................20 TH-409 ............... 5.3....................18 TH-410 ............... 5.3....................18 TH-4118 ............. 5.3....................18 TH-412 ............... 5.3....................18 TH-416 ............... 6.2.1.................21 TH-417 ............... 6.2.1.................21 TH-418 ............... 6.2.1.................21 TH-419 ............... 6.2.1.................21 TH-420 ............... 6.2.1.................21 TH-421 ............... 6.2.1.................21 TH-422 ............... 6.2.1.................21

TH-424 ................6.2.1 ................ 21 TH-425 ................6.2.1 ................ 21 TH-428 ................6.2.2 ................ 22 TH-429 ................6.2.2 ................ 22 TH-430 ................6.2.2 ................ 22 TH-431 ................6.2.2 ................ 22 TH-434 ................7.1.1 ................ 24 TH-435 ................7.1.1 ................ 24 TH-436 ................7.1.1 ................ 24 TH-437 ................7.1.1 ................ 24 TH-438 ................7.1.1 ................ 24 TH-439 ................7.1.1 ................ 24 TH-440 ................7.1.1 ................ 24 TH-442 ................7.1.2 ................ 25 TH-443 ................7.1.2 ................ 25 TH-444 ................7.1.2 ................ 25 TH-445 ................7.1.2 ................ 25 TH-446 ................7.1.2 ................ 25 TH-450 ................7.1.3 ................ 25 TH-451 ................7.1.3 ................ 25 TH-452 ................7.1.3 ................ 25 TH-453 ................7.6 ................... 26 TH-454 ................7.6 ................... 26 TH-455 ................7.6 ................... 26 TH-456 ................7.6 ................... 26 TH-458 ................7.2 ................... 25 TH-460 ................7.3 ................... 25 TH-461 ................7.3 ................... 25 TH-462 ................7.3 ................... 25 TH-464 ................7.4 ................... 26 TH-466 ................7.8 ................... 27 TH-467 ................7.8 ................... 27 TH-469 ................8.1 ................... 31 TH-470 ................7.14.2 .............. 29 TH-471 ................7.14.4 .............. 29 TH-472 ................7.14.4 .............. 29 TH-491 ................5.2 ................... 17 TH-492 ................5.2 ................... 17

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INTENTIONALLY BLANK

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DOCUMENT CHANGE DETAILS

ISSUE CHANGE AUTHORITY CLASS RELEVANT INFORMATION/INSTRUCTIONS

1 n/a n/a Initial Issue of Document

DISTRIBUTION LIST

INTERNAL EXTERNAL Configuration Management

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