Deployable Boom Thruster Arrangement for Geosynchronous Spacecraft

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Solution Overview

Problem

Xenon-Ion thrusters in geosynchronous orbit spacecraft face challenges in minimizing plume erosion, preventing communications signal distortion, supporting orbit transfer and mission-orbit stationkeeping, and adhering to launch vehicle fairing constraints, while avoiding thermal impacts and thruster interactions.

Innovation Solution

The thrusters are arranged on the spacecraft body with booms that pivot between stowed and firing positions, allowing rotation about nonparallel axes to minimize plume effects and position thrusters efficiently for both stationkeeping and orbit transfer, with lateral separation and adjustable boom lengths to optimize thrust vectors and reduce thermal impacts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If thrusters are positioned close to the spacecraft body to fit within launch vehicle fairing constraints, then ease of manufacture and compactness are improved, but plume erosion of surfaces and thermal impacts to components worsen

Engineering Contradiction:
ImprovecompactnessVSAvoidplume erosion and thermal impacts
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent employs deployable booms that can extend and retract to dynamically adjust thruster positioning. During launch, booms are retracted to keep thrusters compact within the fairing. During operation, booms are extended to position thrusters farther from the spacecraft body, reducing plume erosion and thermal impacts while maintaining manufacturing compactness.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention positions thrusters on booms that extend in multiple dimensions away from the spacecraft body, utilizing three-dimensional space to achieve separation between thrusters and sensitive surfaces. This spatial distribution in multiple dimensions allows simultaneous satisfaction of compact launch requirements and operational protection requirements.

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

2Productivity

If thrusters are arranged to support both orbit transfer and stationkeeping efficiently, then productivity is improved, but device complexity increases due to multiple thrusting directions

Engineering Contradiction:
Improvemission efficiencyVSAvoidthruster arrangement complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent configures thrusters with adjustable boom positions and orientations so that the same thruster assembly can perform multiple functions: orbit transfer maneuvers, East-West stationkeeping, North-South stationkeeping, and attitude control. This multi-functionality eliminates the need for separate propulsion systems for different mission phases, improving productivity while managing complexity through unified design.

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

Solution Approach 2:

The deployable booms provide dynamic reconfiguration capability, allowing the thruster geometry to be optimized for different mission requirements. The same physical thrusters can be positioned at different locations and orientations to efficiently perform various maneuvers, reducing the need for additional dedicated thruster groups.

Inventive Principle:
Principle #15Dynamics

3Reliability

If thrusters are separated laterally to minimize plume interactions, then reliability is improved, but the area occupied by the thruster system increases

Engineering Contradiction:
Improvethruster operation reliabilityVSAvoidthruster system area
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The deployable boom structure allows lateral separation of thrusters during operational phases to minimize plume interactions and improve reliability. During launch, the booms are retracted to minimize the occupied area. This dynamic adjustment of lateral separation distance resolves the contradiction between reliability improvement and area occupation.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3116785B1Thruster arrangement for geosynchronous orbit spacecraft
Publication Date: 2020.05.06 LOCKHEED MARTIN CORP
  • EP3116785B1 patent drawingFigure 1A~1B
  • EP3116785B1 patent drawingFigure 2
  • EP3116785B1 patent drawingFigure 3~4

AI summary

According to some aspects of the subject disclosure, a spacecraft comprises first and second pluralities of thrusters. The pluralities of thrusters are attached to a spacecraft body by booms configured to move the first plurality of thrusters between stowed and deployed positions. The deployed position of the first plurality of thrusters is farther north than is the stowed position of the first plurality of thrusters. The deployed position of the second plurality of thrusters is farther south than is the stowed position of the second plurality of thrusters. The first plurality of thrusters comprises a first thruster and a second thruster separated from each other in an east-west direction. The second plurality of thrusters comprises a third thruster and a fourth thruster separated from each other in the east-west direction.