Pyrogenic Adhesive Joint for Clean Spacecraft Stage Separation

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Solution Overview

Problem

Current connection-separation systems for spatial launchers and missiles generate debris, cause significant structural impact, and leave asperities, making them unsuitable for fragile payloads and high-mechanical-load applications.

Innovation Solution

A device and method using a pyrogenic material, such as thermite, placed in a tube between two elements, with a thermally insulating adhesive and a metallic retainer system, allowing for remote pyrotechnic triggering to achieve smooth separation by rapid warming of the adhesive, minimizing impact and debris.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If pyrotechnic cutting off by local melting or rupture is used, then separation is achieved, but debris is generated and significant structural impact occurs

Engineering Contradiction:

Improveseparation capabilityVSAvoiddebris and structural impact

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces an intermediary substance (adhesive or polymer material) between the two elements to be separated. This intermediary material is designed to melt or decompose cleanly at controlled temperatures, enabling separation without generating debris or significant impact. The intermediary acts as a sacrificial element that facilitates separation while protecting the main structures from damage.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent utilizes parameter changes in the intermediary material's physical and chemical properties. By selecting materials with specific melting points or decomposition temperatures that can be precisely controlled, the separation process occurs at optimal temperatures that prevent debris generation. The material's phase transition parameters are engineered to enable clean separation while minimizing thermal impact on surrounding structures.

Inventive Principle:

Principle #35Parameter changes

2Force

If multiple bolts are used for connection, then force transmission is improved, but failure risk increases due to number of devices

Engineering Contradiction:

Improveforce transmissionVSAvoidfailure risk

Core Design Contradiction:

ForceVSReliability

Solution Approach 1:

The patent merges the connection function into a single integrated adhesive joint rather than using multiple separate bolts. This unified connection approach maintains adequate force transmission through the adhesive's bonding strength while eliminating the complexity and failure risks associated with multiple fastening components. The adhesive provides continuous force distribution across the connection surface.

Inventive Principle:

Principle #5Merging (Combining)

3Productivity

If conventional connection systems are used, then separation is achieved, but asperities are left on the external shape

Engineering Contradiction:

Improveseparation capabilityVSAvoidsurface smoothness

Core Design Contradiction:

ProductivityVSShape

Solution Approach 1:

The patent employs a disposable intermediary adhesive material that is designed to be consumed during the separation process. This sacrificial adhesive cleanly decomposes or melts away, leaving no asperities or residue on the external surfaces. The material's temporary nature allows it to facilitate separation without compromising the surface integrity of the permanent structures.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

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

Enables clean, low-impact separation of stages or payloads, preserving the integrity of both elements and preventing structural damage, while ensuring the connecting means are securely separated without generating metallic debris.

Implementation Method 1

a pyrogenic material, heat generator, placed close to the connecting means... The pyrogenic material is ignited, pyrotechnically, with the triggering means placed remotely in relation to the connection between the first element and the second element

Methodology Applied

Scientific EffectCombustion: Combustion

Implementation Method 2

causes a rapid warming-up of one portion of at least the pyrogenic type material... causes the warming-up of the adhesive

Methodology Applied

Scientific EffectThermal energy transfer: Conduction (thermal)

Implementation Method 3

the adhesive is a thermally insulating adhesive in relation to the tube and the first and second elements

Methodology Applied

Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentUS11492146B2Method and device for the connection and linear separation of two elements stuck together

Publication Date: 2022.11.08 ARIANEGRP SAS

AI summary

The invention relates to a device and a method for the connection and linear separation of two elements, such as the two stages of a spacecraft, consisting in using a tube containing a pyrogenic-type material and a glue arranged around the tube, particularly in contact with the elements. The pyrotechnic triggering of the pyrogenic material causes heating and the melting or carbonisation of the glue and the separation of the two elements.