Spacecraft Actuation via Multi-Mirror Light Reflection

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Solution Overview

Problem

Current spacecraft actuation methods, such as cold gas or electric thrusters, lack precision, have limited lifespan, and can create polluting environments, while using sunlight for propulsion only allows for single-direction force generation, failing to efficiently induce multiple torques and translations.

Innovation Solution

A device comprising a primary mirror, a secondary mirror, and multiple auxiliary mirrors, along with selective positioning means, to reflect sunlight and induce various forces and torques by directing the secondary light beam in different directions, allowing for precise control of spacecraft position and attitude with minimal energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If cold gas or electric thrusters are used for spacecraft actuation, then the spacecraft can achieve position and attitude control, but the system has limited lifespan due to fuel consumption and creates polluting gas/plasma environments

Engineering Contradiction:
Improveactuation reliabilityVSAvoidthruster lifespan
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The system uses sunlight as a free, unlimited energy source that requires no fuel consumption. The optical mirrors and positioning system enable continuous operation without depletable resources, making the system self-sustaining for position and attitude control

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces mechanical/chemical propulsion systems (thrusters consuming fuel) with an optical system using sunlight reflection. This substitution eliminates fuel consumption and the associated pollution while providing continuous actuation capability

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If electric thrusters are used for spacecraft actuation, then the spacecraft can achieve position and attitude control, but high power consumption influences the spacecraft design

Engineering Contradiction:
Improveactuation reliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system harnesses sunlight as a free energy source, requiring minimal power only for the positioning actuators rather than high power for propulsion. This dramatically reduces energy consumption while maintaining actuation reliability

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces high-power electric thrusters with a low-power optical system that uses sunlight pressure. The energy required is only for positioning the mirrors, not for generating propulsion force, thus reducing power consumption

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If a single secondary mirror is used to reflect sunlight, then the system is simple, but it can only generate a single force in a single chosen direction

Engineering Contradiction:
Improvesystem complexityVSAvoidforce direction control
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent divides the light reflection function across multiple auxiliary mirrors (at least two) positioned at different locations. Each mirror can be independently positioned to reflect light in different directions, enabling generation of multiple forces and torques while maintaining system simplicity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system adds spatial dimensionality by positioning multiple auxiliary mirrors at different locations around the spacecraft. This enables control of force directions in three-dimensional space, allowing generation of torques around three axes and forces in multiple directions

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Measurement precision

If multiple nozzles and controls are used to generate different forces and torques, then the spacecraft can achieve precise control, but the device complexity increases

Engineering Contradiction:
Improveposition control precisionVSAvoidactuation system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent makes the secondary mirror and auxiliary mirrors serve multiple functions: they can be positioned to generate forces in different directions, torques around different axes, and combinations thereof. This multi-functionality reduces the need for separate nozzles and controls for each degree of freedom

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

Solution Approach 2:

The system uses dynamic positioning of the auxiliary mirrors to achieve different actuation effects. By moving the mirrors to different positions, the same optical components can generate different forces and torques, providing precise control without fixed directional nozzles

Inventive Principle:
Principle #15Dynamics

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 precise control of spacecraft position and attitude with reduced energy consumption, eliminating pollution and simplifying the actuation system by using a single actuator to generate all possible forces and torques around three axes, enhancing mission precision and reducing system complexity.

Implementation Method 1

a fixed primary mirror responsible for reflecting light coming from a celestial body in the direction of a secondary mirror

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 2

this secondary mirror being itself responsible for reflecting in (at least) a chosen direction at least part of the primary light beam

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 3

at least two auxiliary mirrors placed at chosen locations and responsible for reflecting at least part of the secondary light beam which comes from the secondary mirror in different directions chosen so as to induce different movements of the spacecraft

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 4

it only makes it possible to generate a single force in a single chosen direction... reflecting at least a fraction of the primary light beam in a direction chosen so as to induce thrust on the spacecraft in a direction opposite to the direction of reflection chosen

Methodology Applied
Scientific EffectRadiation pressure: Radiation Pressure

Data Source

PatentEP1876098B1Device for powering a spaceship by reflecting astral light off auxiliary mirrors placed in different directions
Publication Date: 2010.06.02 THALES SA
  • EP1876098B1 patent drawingFigure 1~3

AI summary

The device (D) has a fixed mirror (M1) reflecting a solar light (LS) under the form of light beam (FP) in the direction of another mirror (M2) that reflects a part of the beam under the form of another light beam (FS). Auxiliary mirrors (MA1-MA8) are placed in a chosen location and reflect a part of the beam (FS) in different chosen directions to induce different displacements of a spacecraft (S) e.g. observation satellite. A selective positioning unit (MP) i.e. piezoelectric actuator, reflects the beam (FS) in the direction of one auxiliary mirror to induce a spacecraft`s chosen displacement. An independent claim is also included for a space craft assembly for flying in order.