Two-Axis Payload Pointing Mechanism Without HDRMs

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Solution Overview

Problem

Existing pointing systems for spacecraft, such as thrusters, require a large number of immovably positioned thrusters, increasing mass and leading to imprecise movement, and rely on Hold Down Release Mechanisms (HDRMs) that add complexity and mass, which are unreliable and costly.

Innovation Solution

A two-axis pointing system with a pedestal, support plate, and rotary actuators that allow for movement in two rotational degrees of freedom, integrated thermal control, and routing of components to minimize exposure to radiation and debris, eliminating the need for HDRMs and reducing the number of thrusters required.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a large number of immovably positioned thrusters are used, then propulsion capability is provided, but mass increases and movement precision deteriorates

Engineering Contradiction:
Improvepropulsion capabilityVSAvoidmass
Core Design Contradiction:
Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The thruster assembly is made movable through a two-axis pointing mechanism with rotational degrees of freedom, allowing the thrusters to be dynamically repositioned to different orientations rather than being fixed in immovable positions, thereby reducing the number of thrusters needed while maintaining propulsion versatility

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

A single movable thruster assembly can perform multiple propulsion functions by being repositioned to different angles and orientations, replacing the need for multiple fixed thrusters, thus reducing overall system mass while maintaining full propulsion capability

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

2Reliability

If Hold Down Release Mechanisms (HDRMs) are used to secure equipment during launch, then equipment is protected, but mass and device complexity increase

Engineering Contradiction:
Improveequipment protectionVSAvoidmechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The HDRM functionality is integrated directly into the two-axis pointing mechanism structure, combining the hold-down function with the pointing mechanism rather than using separate HDRM components, thereby reducing overall device complexity and mass while maintaining equipment protection during launch

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The pointing mechanism itself provides the hold-down function through its structural design, eliminating the need for separate HDRM systems, as the mechanism can securely hold the thruster assembly in a protected position during launch and then release it for operation

Inventive Principle:
Principle #25Self-service

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 a lightweight, reliable, and versatile propulsion capability with reduced mass, improved maneuverability, and continuous re-pointing capability, while minimizing exposure to radiation and debris, and reducing costs by eliminating HDRMs.

Implementation Method 1

The connection between the pedestal and the support plate may be a spherical bearing or may be universal joint

Methodology Applied
Scientific EffectSpherical bearing: Ball Bearing

Implementation Method 2

The connection between the pedestal and the support plate may be a spherical bearing or may be universal joint

Methodology Applied
Scientific EffectUniversal joint: Gimbal

Implementation Method 3

The thermal control system may include a radiator attached to the support plate. At least one surface of the support plate may act as a thermal radiator

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Data Source

PatentEP4477562A1Two axis pointing mechanism
Publication Date: 2024.12.18 MACDONALD DETTWILER & ASSOC INC
  • EP4477562A1 patent drawingFigure 1
  • EP4477562A1 patent drawingFigure 2
  • EP4477562A1 patent drawingFigure 3

AI summary

Systems and methods for two-axis pointing of payloads are provided. A two-axis pointing system includes a pedestal, a support plate mounted to the pedestal by a connection which allows movement of the support plate in at least two rotational degrees of freedom, a payload mounted to the support plate, a first rotary actuator physically connected to the support plate and operable to move the support plate along a first of the rotational degrees of freedom, a second rotary actuator physically connected to the support plate and operable to move the support plate along a second of the rotational degrees of freedom, a baseplate, wherein the pedestal, the first rotary actuator, and the second rotary actuator are fixed to the baseplate, a plurality of harnesses for supplying at least one of power and telemetry for actuation of the system, and a thermal control system integrated with the support plate.