Spacecraft Linear Release Damped Actuator

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Solution Overview

Problem

Existing spacecraft payload release systems often induce unwanted rotational motion or 'tumble' due to misalignment of the payload's center of gravity with the separating force vector, and are plagued by unpredictable energy releases from explosive devices and preloaded joints, necessitating a controlled and reliable method to minimize mass, size, and cost while ensuring compactness and reliability.

Innovation Solution

A system utilizing a spring-loaded, fluid-filled damped actuator with a piston and control orifices to achieve a substantially constant velocity release, coupled with a linear guide and capture device with spring-loaded latches, which maintains axial forces and isolates lateral moments, allowing for controlled release independent of preloaded devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If explosive devices are used for payload release, then the release can be sudden and forceful, but the energy release becomes unpredictable and imparts rotational motion to the payload

Engineering Contradiction:

Improverelease speedVSAvoidpredictability of release

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent replaces explosive devices with a mechanical spring-loaded actuator system. The spring mechanism provides controlled linear force to separate the payload along the axis of the guide, eliminating unpredictable energy release and rotational motion while maintaining rapid separation capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a guide as an intermediary element between the actuator and payload. The guide constrains the separation motion to a linear path, preventing rotational motion even if the center of gravity is not aligned with the force vector, thus ensuring predictable release.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If multiple release devices are used to separate payload, then the payload can be released from multiple points, but the system complexity and mass increase

Engineering Contradiction:

Improvepayload release controlVSAvoidnumber of release devices

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple release functions into a single integrated actuator-guide mechanism. The spring-loaded actuator provides the separating force while the guide simultaneously constrains the motion path, eliminating the need for multiple separate release devices and reducing system complexity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The guide serves multiple functions: it guides the linear motion of the actuator, constrains the payload separation path, and prevents rotational motion. This multi-functionality reduces the number of components needed while maintaining reliable payload release control.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Strength

If preloaded joints are used in the release system, then the structural integrity is maintained during operation, but stored energy in these joints contributes to unpredictable payload release

Engineering Contradiction:

Improvestructural integrityVSAvoidunpredictable energy release

Core Design Contradiction:

StrengthVSObject-generated harmful factors

Solution Approach 1:

The patent removes preloaded joints from the release system entirely. The design uses a direct spring-loaded actuator that does not rely on preloaded joints, thereby eliminating the stored energy that could contribute to unpredictable payload release while maintaining structural integrity through the guide and actuator assembly.

Inventive Principle:

Principle #2Taking out (Extraction)

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 ensures predictable and controlled payload release with minimized rotational motion, reducing mass and cost, and enhancing reliability by using a compact, lightweight design that operates passively, thus avoiding the inefficiencies of multiple mechanisms or pyrotechnic devices.

Implementation Method 1

a control orifice that restricts the fluid flowing from one side of the piston to the other and results in a substantially constant damped motion of the piston

Methodology Applied

Scientific EffectFluid flow restriction through orifices: Pressure Drop

Implementation Method 2

a substantially constant damped motion of the piston

Methodology Applied

Scientific EffectDamping: Damping

Implementation Method 3

Spring loaded latches are held in a closed position by the side walls of the guide as the capture device moves

Methodology Applied

Scientific EffectSpring force: Spring

Data Source

PatentUS7644891B2Spacecraft low tumble linear release system

Publication Date: 2010.01.12 THE BOEING CO

AI summary

Systems and methods for releasing a spacecraft payload at a substantially constant velocity are disclosed. A linear actuator is used that includes a spring loaded and fluid filled chamber. The spring drives against a piston within the chamber that includes a control orifice that restricts the fluid flowing from one side of the piston to the other and results in a substantially constant damped motion of the piston. The piston drives a rod from the chamber that is attached to a capture device that holds a flange of the spacecraft payload. The capture device moves along a linear guide toward an open end. Spring loaded latches are held in a closed position by the side walls of the guide as the capture device moves. The latches release the flange as exit the open end of the guide.