Flexible Radiator with Pyrolytic Graphite for Spacecraft Thermal Management

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Solution Overview

Problem

Existing radiators in spacecraft face challenges in combining structural and thermal functions, particularly when radiator temperatures are incompatible with the spacecraft structure, leading to mass, cost, and manufacturability issues, and the need for separate thermal and structural systems.

Innovation Solution

A radiator design featuring a pyrolytic graphite heat conductive layer with a high in-plane heat conductivity of at least 500 W/mK, paired with a high emissivity heat emission layer, and a flexible laminate structure that includes a heat supply device, allowing for adaptable shape conforming to satellite housing irregularities, and optionally integrated insulation for thermal decoupling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of stationary object

If a rigid panel structure is used to fulfill both structural and thermal functions, then mass is reduced and structural strength is improved, but the radiator cannot be made flexible and adaptable to irregular surfaces

Engineering Contradiction:
ImprovemassVSAvoidflexibility
Core Design Contradiction:
Weight of stationary objectVSAdaptability or versatility

Solution Approach 1:

The radiator is divided into multiple segments that can be folded or deployed, allowing the rigid panels to be stored in a compact configuration during launch and deployed to a large surface area in orbit, providing both structural integrity and adaptability to irregular surfaces

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A flexible substrate or thin film layer is introduced between the rigid thermal control elements and the supporting structure, allowing the overall assembly to conform to irregular surfaces while maintaining the rigidity needed for thermal function

Inventive Principle:
Principle #30Flexible shells and thin films

2Strength

If the radiator is thermally coupled to the supporting structure, then structural integrity is improved, but temperature incompatibility causes harmful thermal effects

Engineering Contradiction:
Improvestructural integrityVSAvoidtemperature incompatibility
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

A thermal isolation layer or thermally insulating material is introduced between the radiator and the supporting structure, allowing mechanical coupling for structural integrity while preventing harmful thermal transfer between components with incompatible temperature requirements

Inventive Principle:
Principle #24Intermediary (Mediator)

3Temperature

If standoffs and multilayer insulation are used to thermally decouple the radiator, then temperature compatibility is improved, but device complexity and mass increase

Engineering Contradiction:
Improvetemperature compatibilityVSAvoiddevice complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The thermal isolation function is merged with the mounting structure itself, integrating the thermal decoupling capability into the existing structural components rather than adding separate standoffs and insulation layers, thereby reducing overall device complexity

Inventive Principle:
Principle #5Merging (Combining)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The radiator achieves enhanced heat transport and emission capabilities while being flexible and adaptable, reducing mass and cost by decoupling thermal and structural functions, and providing protection against incompatible temperatures.

Implementation Method 1

a first heat conductive layer (2) of pyrolytic graphite material, having an in-plane heat conductivity of at least 500 W/mK

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

a second heat emission layer (3) in contact with the heat conductive layer, the second layer having an exposed surface with an emissivity of at least 0,7

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Data Source

PatentEP2907757B1Radiator, as well as space vehicle structure comprising such a radiator
Publication Date: 2017.08.02 AIRBUS DEFENCE & SPACE NETHERLANDS
  • EP2907757B1 patent drawingFigure 1
  • EP2907757B1 patent drawingFigure 2
  • EP2907757B1 patent drawingFigure 3

AI summary

A radiator (1) comprises at least one heat conductive layer (2) having an in-plane heat conductivity of at least 500 W/mK and at least one heat emission layer (3) in contact with the heat conductive layer, wherein the emission layer has an exposed surface with an emissivity of at least 0,7. Preferably, the heat conductive layer comprises pyrolytic graphite material. The radiator is to be used in combination with a space vehicle structure, and due to its flexible character may be conformed to the particular shapes of such structure (18).