Spacecraft Hold-Down Ring Clamp for High-Load Low-Shock Release

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Solution Overview

Problem

Existing spacecraft separation systems, such as HRS type systems, have limited load capacity and generate significant shock during release, necessitating multiple actuators and discrete point interfaces, which are costly and inefficient for larger satellites.

Innovation Solution

A system comprising an upper and lower ring bracket with an internal assembly of levers, clamps, guiding systems, and a central rod, allowing for a single actuator to handle high loads and reducing shock through a demultiplication mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If HRS type systems with discrete point interfaces are used, then the spacecraft can be separated from the launcher, but the load capacity is limited to around 30kN per pyronut requiring multiple actuators

Engineering Contradiction:
Improveload capacityVSAvoidnumber of actuators
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The separation system is divided into multiple clamp bands that wrap around the spacecraft, with each band providing distributed load support. This segmentation allows a single actuator to control multiple separation points simultaneously, increasing load capacity without proportionally increasing actuator count

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The clamp band structure serves multiple functions: it provides mechanical holding force, distributes loads across multiple points, and enables single-actuator control of multiple separation locations. This multi-functionality resolves the contradiction by making one actuator perform the work of multiple separate actuators

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Force

If multiple actuators are used per separation point to handle flight loads, then the load capacity increases, but the price and trigger lines complexity increase

Engineering Contradiction:
Improveload capacityVSAvoidtrigger lines
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

Multiple separation functions are merged into a single clamp band assembly controlled by one actuator. The actuator simultaneously controls multiple pyronuts or release mechanisms along the clamp band, reducing the number of independent trigger lines needed while maintaining high load capacity

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If HRS is released without shock reduction mechanism, then the separation is simple, but significant shock is generated

Engineering Contradiction:
Improveseparation simplicityVSAvoidshock
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The clamp band system is designed with inherent shock-absorbing characteristics through its flexible band structure and distributed contact points. The gradual release mechanism and elastic deformation of the band material provide cushioning before separation, reducing shock while maintaining operational simplicity

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 system provides high load capacity with a single actuator per point, reduces shock during separation, and can be easily coupled to spacecraft and launchers, suitable for large satellites with discrete interface points.

Implementation Method 1

The central rod is joined to the central beam, is preloaded in a closed state of the system by torquing an upper nut

Methodology Applied
Scientific EffectTorque: Torque

Implementation Method 2

The system is an assembly that basically comprises an internal hold down and release device, a bracket configured to be attached to a spacecraft and a bracket configured to be attached to a launcher... When the satellite needs to be separated from the launcher, four pyronuts are activated

Methodology Applied
Scientific EffectPyrophoricity: Pyrophoricity

Data Source

PatentEP4691921A1System for hold down and release of a spacecraft with respect to a launcher
Publication Date: 2026.02.11 AIRBUS DEFENCE & SPACE SAU
  • EP4691921A1 patent drawingFigure 1~7
  • EP4691921A1 patent drawingFigure 8~14
  • EP4691921A1 patent drawingFigure 15

AI summary

System (1) for hold down and release of a spacecraft with respect to a launcher, configured to be able to change from a closed state to an open state, that comprises: - an upper bracket (2) in the form of a ring comprising an inner protruding portion (4), - a lower bracket (3) in the form of a ring comprising an inner protruding portion (4'), - an internal assembly (5) fixed to the lower bracket (3) that comprises a central beam (6), at least three levers (7), at least three clamps (8), at least three guiding systems for the clamps (8), a central rod (11) and an actuator (12), wherein: - the upper bracket (2) and the lower bracket (3) enclose an interior hollow space where the internal assembly (5) is placed in a closed state of the system (1), - the clamps (8) of the internal assembly (5) have a peripheral groove (13) configured to mate with the protruding portions (4, 4') of the upper bracket (2) and the lower bracket (3), - each lever (7) is rigid, is articulated to a clamp (8) by a hinge (14) and to the central beam (6) by a hinge (14') and comprises a latch system (15) to fix the lever (7) on the central beam (6) in an open state of the system (1), - the clamps (8) are guided by the guiding systems that allow the radial movement of the clamps (8), each guiding system comprising a guide (9) on which at least one pin (10) protruding from the corresponding clamp (8) is fitted, and - the central rod (11) is joined to the central beam (6), is preloaded in a closed state of the system (1) by torquing an upper nut (19) and is releasable by the action of the actuator (12).