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Cryosat Solar Panel Substrate Technical Specifications 12SP072B

Emcore Proprietary & Confidential 1

CRYOSAT SOLAR PANEL SUBSTRATE TECHNICAL SPECIFICATION EMCORE DOC. NO. 12SP072 Revision B



REVISION HISTORY

REVISION REASON FOR CHANGE

EWSP09015A Initial Release 12SP072A Migration to new configuration management system from EWSP09015A 12SP072B 1. Changed section ‘3.1.4 Local Flatness’ from

3.1.4 Local flatness The panels Kapton® face flatness shall be better than 0.2 mm on a 30 mm length area. To 3.1.4 Local Flatness Cell Side: 0.13mm deviation in any 100mm x 100mm area. Non-Cell Side: 1 mm deviation in any 100mm x 100mm area. 2. Added section 3.6: 3.6 Visual Inspection Requirements 3.6.1 Dents Not to exceed flatness as specified in section 3.1.4. 3.6.2 Dimples and Protrusions Not to exceed flatness as specified in section 3.1.4 3.6.3 Edge Damage Chips at the edge of the panel skins shall not exceed 2.5mm long and 1.3mm deep ( or into the panel). Chips within this criteria shall have all rough and sharp edges removed by diamond file or abrasive sheet. The edges of the anomaly should be coated with a low viscosity two part, room temperature adhesive to dis-allow intra-laminar peel.



Cryosat Solar Panel Substrate Technical Specification

Table of Contents

1. SCOPE 5

2. DOCUMENTS 5

2.1 Applicable Documents 5

2.2 Reference Documents 5

3. REQUIREMENTS 6

3.1 Mass, dimensions and geometry 6 3.1.1 Geometry 6 3.1.2 Interfaces and boundary conditions 6 3.1.3 Interfaces flatness 7 3.1.4 Local Flatness 7 3.1.5 Mass 7 3.1.6 Centre of gravity 8 3.1.7 Moment of inertia 8

3.2 Mechanical requirements 8 3.2.1 Stiffness 8 3.2.2 Strength and Safety margins 8 3.2.3 Safety margins and safety factors 9 3.2.4 Quasi-static loads 9 3.2.5 Interface loads : 9 3.2.6 Sine vibration loads 10 3.2.7 Acoustic loads 11

3.3 Thermal requirements 11 3.3.1 Thermo-optical characteristics 11 3.3.2 Temperature limits 11

3.4 Electrical requirements 12 3.4.1 Insulation 12 3.4.2 Grounding 12 3.4.3 Magnetic Materials 12

3.5 Mission requirement 12 3.5.1 Life duration 12 3.5.2 Venting 12 3.5.3 Out-gassing 12 3.5.4 Radiation tolerances 13 3.5.5 ATOX 13



3.6 visual inspection requirements 13 3.6.1 Dents 13 3.6.2 Dimples and Protrusions 13 3.6.3 Edge Damage 13

4. VERIFICATION 14

4.1 Analyses 14

4.2 tests 14 4.2.1 In process tests 14 4.2.2 Static test on panels 15 4.2.3 Thermal Vacuum tests on substrate level 15

4.3 Inspections 15

5. PREPARATION FOR DELIVERY 16

5.1 Handling 16

5.2 Cleaning 16

5.3 Marking 16

5.4 transport 16



1. SCOPE

This document presents Technical Specifications for the solar array substrates.

The CRYOSAT Solar Array substrates consist of 2 symmetrical panels which shall support the solar cells and electrical network. They are attached with isostatic conditions to the spacecraft structure, and not submitted to any deployment phase. They are connected together through 5 cleats.

The substrates are flat composite panels, in a sandwich construction with CFRP skins and aluminum honeycomb core. A Kapton® film, 50µm thick, provides electrical insulation on cells bonding face of the substrate.

2. DOCUMENTS

2.1 APPLICABLE DOCUMENTS

Applicable documents form part of the requirements.

[R1] Solar array requirements specification CS-RS-DOR-PP-0001 issue 3, dated July 15, 2002 The contractor has to demonstrate the compliance to [R1], following the transfer matrix as appended. In case of conflict [R1] supersedes the requirements of this document. [R2] Panel interface drawings

2517_232100A00A -Y_Solar_Panel Sheet 1 at issue F Sheet 2 at issue B

2517_232200A00A +Y_Solar_Panel Sheet 1 at issue E Sheet 2 at issue B

[R3] PA Requirements for Subcontractors and suppliers CS-RS-DOR-PA-0001 issue 5

2.2 REFERENCE DOCUMENTS

[R4] Cryosat phase B Radiation environment analysis

CS-TN-GMV-SY-0002 issue 1 dated Sept. 98

[R5] EMCORE Photovoltaics Product Assurance Plan, 12PA003E



3. REQUIREMENTS

3.1 MASS, DIMENSIONS AND GEOMETRY

3.1.1 Geometry

Overall dimensions of the panels are : 3326 mm by 1400 mm. The maximum panels thickness is 40 mm. Greater thickness may be acceptable in inserts areas, pending customer approval.

The angle between the 2 panels and the spacecraft XY – plane is 38°, the (y = –71mm; z=0mm) edge of the envelope coincides, appropriate clearances from the envelope to account for tolerances and dynamic movement shall be considered.

3.1.2 Interfaces and boundary conditions

Interface position and tolerances shall be in accordance with requirements of interface drawings [R2].

The contact area between inserts and spacecraft brackets shall be 0.5mm above the substrate to avoid contact between bracket and substrate.

For mechanical analysis, the panels are considered fixed as indicated on the table below :

A1 A2 B C X free free fixed free Y’ fixed fixed free free Z’ fixed fixed fixed fixed

The mounting struts shall be taken into account by their stiffness and geometry. They shall be translational fixed at their interface to the S/C. The Mounting strut stiffness is 22000N/mm. The strut angle to the XY-plane is 13.9° and to the X-axis 32.9°.



3.1.3 Interfaces flatness

The panel substrates inserts contact areas shall be in a common plane, within a ± 1 mm tolerance.

3.1.4 Local Flatness

Cell Side: 0.13mm deviation in any 100mm x 100mm area. Non-Cell Side: 1 mm deviation in any 100mm x 100mm area.

3.1.5 Mass

The overall maximum mass of the mechanical assembly (two panels and five cleats shall be lower than 42 Kg.

The solar cell and electrical network mass to take into account for analysis is 1.7 Kg/m².

An additional uniform mass of 0.6 Kg/m² shall be taken into account for analyses (representative of MLI installed on panels rear face).



3.1.6 Centre of gravity

The Solar Array centre of gravity shall be calculated through the Finite Element Model and given in the satellite reference frame.

3.1.7 Moment of inertia

The Solar Array moments of inertia shall be calculated through the Finite Element Model and given in the satellite reference frame.

3.2 MECHANICAL REQUIREMENTS

3.2.1 Stiffness

Assuming a rigid spacecraft and the two panels connected together, the first reso-nance frequency of the solar array with a modal mass higher than 10% of overall mass shall be >50Hz.

3.2.2 Strength and Safety margins

The design shall guarantee positive margins of safety against yielding, rupture and buckling when subjected to :

- the quasi-static loads specified in §3.2.4

- the interface loads specified in §3.2.5

- the loads induced by dynamic environment specified in §3.2.6 and §3.2.7

- the loads induced by thermal environment specified in § 3.3.2.

Quasi-static and dynamic loads shall be considered at ambient temperature, as they correspond to the launch phase.



3.2.3 Safety margins and safety factors

The safety margin is defined as:

1−×

=fSe

aMSσσ

σa : Yield or Ultimate stress (depends on materials)

σe : Expected stress induced by qualification environmental loads

Sf : safety factor to consider, according to following table :

Item Yield Ultimate Buckling Metallic material 1.25 1.5 2

Non-metallic materials 1.5 2 2

Inserts and Joints 1.5 2

For on ground operations, safety factor shall not be less than 2.

3.2.4 Quasi-static loads

The panel substrates shall withstand following qualification quasi-static loads :

Case a) 20g axial 10g lateral

Case b) 5g axial and 15g lateral

3.2.5 Interface loads :

The substrates shall be compatible with following dynamic interface loads.



Direction A1 A2 B C D Strut FX (N) 100 100 8500 100 1350 (1) - FY' (N) 3500 6200 100 100 600 (1) - FZ' (N) 350 350 200 950 1200 (1) - MX (Nm) 130 232 25 5 - - MY’ (Nm) 15 15 255 5 - - MZ’ (Nm) 15 15 110 5 - - 5200 N (2)

(1) In spacecraft coordinates system (2) In strut axis direction

These values cover loads induced by thermal gradients and CTE differences between SA and Spacecraft.

3.2.6 Sine vibration loads

Sine vibration qualification levels are defined here below.

5 - 50 Hz 50 - 100 Hz

X(SC)-direction 20g 6g

Y(SC)-direction 15g 6g

Z(SC)-direction 15g 6g

Notching of input levels are allowed in order not to exceed maximum quasi-static loads at the holddown to the side-wall interface or not to exceed 100g locally.

No contact shall occur between the panels and any other element when subjected to the launch dynamic environment.



3.2.7 Acoustic loads

The S/A panel substrate design shall comply with acoustic Sound Pressure Levels (SPLs) as given below, plus a qualification factor of 3.5dB.

Acoustic Noise Flight Loads in dB

[Hz] 31.5 129.8 63 131.8

125 134.8 250 135.8 500 136.5 1000 131.6 2000 126.8 4000 123.1 8000 115.0 OSPL 142.0

3.3 THERMAL REQUIREMENTS

3.3.1 Thermo-optical characteristics

The thermo-optical coating of the backside of the SA panel substrates are bare CFRP properties :

• ε = 0.81

• α = 0.92

3.3.2 Temperature limits

The ground and storage temperature range is –30°C / +40°C.

The extreme design temperatures are :

Hot operational temperature

Hot non operational temperature

Cold operational temperature

Cold non operational temperature

+130°C +145°C -170°C -170°C

The panel substrates shall withstand this thermal environment without damage.



3.4 ELECTRICAL REQUIREMENTS

3.4.1 Insulation

The electrical network shall be insulated from the sandwich structure by a 50µm thick Kapton® layer. The required insulation resistance is 10 MΩ under 250V DC.

The inserts shall be electrically isolated from the substrate. The required insulation resistance is 10 MΩ under 250V DC.

3.4.2 Grounding

The grounding of the sandwich structure is foreseen in the design in order to avoid ESD phenomenon.

Two inserts installed on the panels rear face shall be used as grounding reference. With respect to these two inserts, any point of the sandwich structure shall display a maximum resistance of 500 Ω.

3.4.3 Magnetic Materials

The use of magnetic materials shall be avoided.

3.5 MISSION REQUIREMENT

3.5.1 Life duration

The minimum life time shall be 2 years on ground and 3.5 years in orbit.

3.5.2 Venting

The panel substrates shall withstand a change of pressure from the ambient pressure to vacuum with a rate of 50 mbar/s without degradation.

In orbit, the ambient pressure to consider is 10-10 mbar.

3.5.3 Out-gassing

The materials implemented on the substrates shall be compliant with out-gassing requirements issued from the ESA specification ECSS-Q70-02A :

• Residual weight loss (RWL) < 1%

• Collected volatile condensable materials (CVCM) < 0.1%



3.5.4 Radiation tolerances

The substrates shall suffer no damage after exposure of radiation environment as defined in [R4].

3.5.5 ATOX

The substrates shall suffer no damage after exposure of ATOX (atomic oxygen) environment as defined in [R4], but no specific protection against ATOX is requested.

3.6 VISUAL INSPECTION REQUIREMENTS

3.6.1 Dents

Not to exceed flatness or 0.13mm deep, whichever is smaller. No more than 2 such defects in any 100mm x 100mm area.

3.6.2 Dimples and Protrusions

The maximum depth of dimples and height of protrusions on the cell side shall not exceed 0.10mm.

3.6.3 Edge Damage

Chips at the edge of the panel skins shall not exceed 2.5mm long and 1.3mm deep (or into the panel). Chips within this criterion shall have all rough and sharp edges removed by diamond file or abrasive sheet. The edges of the anomaly should be coated with a low viscosity two part, room temperature adhesive to disallow intra-laminar peel.



4. VERIFICATION

The compliance of solar array substrates with all requirements of this document shall be demonstrated, using test, analysis, and review of design or inspection following the relevant substrate requirements of [R1]. Also the test conditions are given in [R1]. Some specific tests are highlighted here.

4.1 ANALYSES

Following analyses are to be performed for design justification :

• Modal analysis

• quasi-static analysis

• sine vibration analyses

• thermal stress analysis

• acoustic analyses (presentation of inherited results from previous programs may be accepted)

4.2 TESTS

Prior to testing, a test procedure will be established.

Tests reports will be edited after test completion.

4.2.1 In process tests

Non destructive tests are performed on all manufactured panels :

- control of inserts bonding

- control of skins to core adhesion

- control of honeycomb junctions

A follow-up coupon is manufactured on the marble, in the same conditions as the panel, in particular with the same polymerisation conditions. From this coupon are cut samples for flatwise tensile tests. Three samples shall be tested per panel, and minimum failure strength shall be greater than 1 MPa.



4.2.2 Static test on panels

Each interface of the first manufactured panel (called PFM) will be tested at qualification level. This qualification level corresponds to the maximum calculated load, for all environments, on the tested interface.

30% of the interface of the second panel will be tested at acceptance level, defined as the qualification level divided by 1.2.

4.2.3 Thermal Vacuum tests on substrate level

2 thermal vacuum cycles on each flight panel are required for environment qualification tests between temperature extremes (-170°C to +145°C).

4.3 INSPECTIONS

Inspections and measurements on all panels shall include:

• mass measurement

• overall flatness measurement

• local flatness measurement

• Kapton face insulation verification

• Grounding inspection

Results shall be reported in the panels' individual inspection reports



5. PREPARATION FOR DELIVERY

5.1 HANDLING

The inserts installed close to substrate edges may be used as hoisting interface for handling.

5.2 CLEANING

The panel substrates shall be cleaned before delivery, with acetone 95 % on rear face and ethanol 95 % on Kapton face.

5.3 MARKING

Identification marking shall be done on the substrates' CFRP face, including at least:

- Project name

- unit name and reference

- serial number

- company name.

Letters size shall be greater than 2mm.

5.4 TRANSPORT

Panel substrates transport shall be made in a specific container adapted for safe transport of the assembled panel (design details to be provided by EMCORE); foam blocks shall be installed in the container in order to avoid any shock between panels and container walls.

Desiccants shall be foreseen to avoid water condensation.



Appendix : transfer matrix between S/A specification [R1] and substrate specification (present document).

For each requirement of the document [R1], it is precisely defined in the following matrix if the requirement is applicable for the substrate or not. In case of conflict, [R1] supersedes the requirements of this document.

§ Title Req. number

Substrates Applicability

Specification document

Comment

3 Solar Array Functional and Performance Requirements

Title

L1-9564 Yes [R2] L1-9574 No L1-3934 No L1-3781 No L1-9575 No L1-9578 No L1-5711 No L1-9569 No L1-3931 No L1-3932 No

L1-11127

No

3.1 Solar Array Configuration & Layout

L1-8275 No L1-3927 No 3.2 Power/Energy

Requirements L1-5695 No L1-5715 Yes § 3.5.4 L1-6788 No L1-6785 No L1-6787 No L1-6786 No L1-5716 Yes § 3.5.5 L1-9579 No

3.3 Degradation and Loss Factors

L1-8724 No L1-6275 Yes TBD Handling interfaces to be

specified L1-6276 No Relatet to electrical

interation L1-6277 Yes § 3.2.1 and §

3.2.6 Compliance w.r.t. shock to be demonstrated by tests at S/A level

3.4 Special Mechanical Requirements

L1-6278 Yes § 3.5.5




Substrates

Applicability


Comment

4 Design and Interface Requirements

Title

4.1 General Design and Interface Requirements

Title

4.1.1 Implementation Requirements

L1-1147 No

4.1.2 Workmanship L1-1959 Yes § 2 L1-2056 Yes § 5.3 L1-2058 Yes § 5.3 L1-2059 Yes § 5.3

4.1.3 Identification and Marking

L1-2060 Yes § 5.3 L1-11750 Yes § 3.5.1 4.1.4 Lifetime / Aging L1-3792 Yes § 3.5

4.1.5 Reliability Requirements Title 4.1.5.1 Electric Power Subsystem

Units Reliability L1-8082 No Considered applicable to

electrical power L1-6047 Yes 4.1.6 Transportation L1-3793 Yes L1-7259 Yes L1-9944 Yes

L1-12446 Yes L1-12447 Yes L1-12448 Yes L1-12449 Yes L1-12450 Yes L1-12451 Yes L1-12452 Yes L1-12453 Yes L1-12454 Yes L1-7261 Yes L1-6154 No

L1-11492 No

4.1.7 GSE Requirements

L1-6155 No L1-11677 Yes § 3.5.2 4.1.8 Pressure and Venting L1-8131 Yes § 3.5.2

4.2 Electrical Design and Interface Requirements

Title

4.2.1 Electrical Design Requirements

Title

4.2.1.1 Bonding, Grounding and Isolation

Title

4.2.1.1.1 Bonding L1-3538 No L1-8406 Yes § 3.4.1

L1-12443 Yes § 3.4.1 L1-5729 No

4.2.1.1.2 Grounding and Isolation

L1-8407 Yes § 3.4.1



L1-8408 Yes § 3.4.1




Substrates

Applicability


Comment

L1-2897 No L1-10553 No L1-10353 No L1-10844 No L1-10357 No

4.2.1.2 Harness and Connector Requirements

L1-10354 No L1-12445 No L1-10097 No

L1-2051 Yes § 3.4.3 L1-2597 No

4.2.1.3 Magnetic Materials

L1-5710 No 4.2.2 Electrical Interfaces

Allocation L1-10096 No

4.2.2.1 Primary Power Interface Allocation

12441 No

L1-6098 No 4.2.2.2 Signal Interface Allocation L1-11126 No

4.2.3 Electrical Interface Characteristics

Title

4.2.3.1 Definitions Title 4.2.3.2 Power Supply Interface

Characteristics Title

4.2.3.2.1 Solar Array Power Interface Characteristics

L1-7491 No

4.2.3.3 Data and Signal Interface Characteristics

Title

L1-6236 No 4.2.3.3.1 Standard Thermistor Interface Characteristics L1-8265 No

4.3 Mechanical and Structural Design and Interface Requirements

Title

4.3.1 Mechanical and Structural Interface Requirements

Title

4.3.1.1 COG Requirement L1-9494 Yes 4.3.1.2 MOI REquirements L1-7691 Yes 4.3.1.1 Mass Requirements L1-8065 No Mass requirement for

substrate only given in [R1]






Comment

4.3.1.2 Accommodation Title 4.3.1.2.1 Electric Power Subsystem

I/F and Accommodation Title

L1-7420 Yes § 3.1.1 L1-7421 Yes [R2] 3.1.1 L1-7422 Yes § 1 L1-7423 Yes [R2] flatness of panel better

than +/- 1mm L1-7424 Yes [R2] L1-7425 Yes [R2] To be included in

interfaces specification L1-7426 Yes [R2] To be included in

interfaces specification L1-11095 Yes L1-12461 No L1-8191 Yes [R2] L1-8194 Yes [R2]

4.3.1.2.1.1

Solar Array I/F and Accommodation

L1-12462 Yes 4.3.2 Mechanical and Structural

Design Requirements Title

L1-6881 Yes § 3.2.1 L1-6885 Yes § 3.1.2 Rotation stiffness to be

precisely defined L1-8043 Yes § 3.1.2 L1-8568 Yes § 3.1.2

4.3.2.1 Stiffness Requirements

L1-12463 Yes [R2] L1-4884 Yes § 3.2.2 Worst combination of

thermal and mechanical loads to be precisely defined

L1-7428 Yes § 3.2.4 L1-8122 Yes § 3.2.5 L1-8125 Yes § 3.2.5 L1-8126 Yes § 3.2.7

4.3.2.2 Strength Requirements

L1-8575 Yes § 3.2.6 L1-12442 Yes 4.3.2.3 FaiI-Safe/Safe-Life Design L1-1961 Yes 4.3.2.4 Safety Requirements L1-5623 Yes L1-1994 Yes § 3.2.3

L1-12094 Yes 4.3.2.4.1 Fatigue Life Factor L1-12095 Yes

4.4 Thermal Design and Interface Requirements

Title

4.4.1 General Thermal I/F Requirements

L1-7265 Yes § 3.3.2 L1-11098 Yes 4.4.1.1 Ground and Storage

Temperature Range L1-7635 Yes § 3.3.2



L1-7636 Yes § 5.4






Comment

4.4.2 Specific Thermal I/F Requirements

Title

L1-6672 Yes § 3.3.1 L1-

12455 Yes

L1-6673 No Depends on solar cells absorptance

4.4.2.1 Solar Array Thermal I/F Requirements

L1-6674 No Depends on solar cells emissivity

L1-12456

Yes

L1-

11148 Yes § 3.3.2 4.4.2.1.1 Solar Array Temperature

Range L1-8404 Yes § 3.3.2

5 Verification Requirements 5.1 General Verification

Requirements Title

L1-2399 Yes § 4 L1-2400 Yes § 4 L1-7462 Yes § 4 L1-6769 Yes § 4 L1-232 Yes § 4 L1-233 Yes § 4 L1-234 Yes § 4

5.1.1 Verification Task

L1-235 Yes § 4 L1-238 Yes § 4.2 5.1.2 General Verification

Requirements for Tests L1-241 Yes § 4.2 L1-243 Yes § 4.1 5.1.3 General Verification

Requirements for Analyses L1-6771 Yes § 4.1 5.1.4 General Requirements

related to Review of Design L1-252 Yes Standard work procedure

L1-256 Yes Id. 5.1.5 General Requirements related to Inspection L1-259 Yes Id.

5.2 Tests Title L1-5890 Yes § 4.2.4 5.2.1 General Test Conditions and

Tolerances L1-5896 Yes 5.2.1.1 Test Data Documentation L1-5898 Yes 5.2.2 Instrument, Subsystem, Unit

and Equipment Level Tests Title

L1-6190 No Test matrix at subsystem level

5.2.2.1 Instrument, Subsystem, Unit and Equipment Tests Matrix

L1-6200 Yes L1-132 No 5.2.2.2 Instrument, Subsystem, Unit

and Equipment Functional Test

L1-10539

No

L1-6804 No 5.2.2.3 Instrument, Subsystem, Units and Equipment Performance Test

L1-6805 No




Substrates Applicabilit

y


Comment

5.2.2.4 Material and Component Qualification Tests

Title

5.2.2.4.1 Material Characterisation Tests

L1-2462 Yes

5.2.2.4.2 Standard Insert Tests L1-2464 Yes 5.2.2.4.3 Specific Insert Tests L1-2466 Yes

L1-2468 Yes 5.2.2.4.4 Sandwich Tests L1-7719 Yes § 4.2.1

5.2.2.4.5 Thermal Tests for Material Combination with High CTE Difference

L1-8577 Yes

5.2.2.5 Insert Acceptance Test L1-12464 Yes § 4.2.2 L1-11494 Yes L1-11149 Yes 2 cycles only L1-12457 No L1-12458 No

5.2.2.6 Unit and Equipment Thermal Vacuum Test

L1-12459 No L1-4010 Yes L1-9948 No On higher level L1-9949 No Id.

5.2.2.6.1 Test Flow

L1-9950 No Id. L1-6808 No Id. L1-9589 No Id.

5.2.2.7 Coupon Level Tests

L1-9588 No Id. 5.2.2.8 Unit EMC Test Title 5.2.2.8.1 Bonding and Isolation L1-9945 No 5.2.2.9 Unit and Equipment

Physical Properties Measurement

L1-146 Yes

5.3 Analyses Title 5.3.1 Unit and Equipment Level

Analyses Title

5.3.1.1 Electrical L1-10042 No L1-5834 Yes § 4.1 No fatigue analysis

foreseen L1-5835 Yes § 4.1 L1-5836 Yes § 4.1

5.3.1.2 Mechanical

L1-5837 Yes § 4.1 5.3.1.3 Instrument, Subsystem and

Units Thermal Analyses L1-9946 Yes § 3.3.1 Thermal properties of

substrates will be provided as requested

- End of Document -

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