PAGE CONTENTS
Objectives
The Flexible Compact Array (FCA) consists of thin flexible blankets equipped with a photovoltaic assembly folded in a zig-zag configuration, which will be deployed using an extendible mast.
Two critical elements of the FCA are developed under this contract, the Stack Rotation Mechanism (SRM) and the Secondary Hold-Down & Release Mechanism (2nd HDRM).
For this project the objectives are:
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Derivation of unit level requirements for the mechanisms under development
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Development and test of engineering models of the SRM and 2nd HDRM
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Realisation of a wing demonstrator that functions as a testbed for the mechanisms under development.
Challenges
The blanket stack to be released contains a photovoltaic assembly that is sensitive to damage caused by mechanical loads induced by the launch environment and the deployment kinematics. Since the deployment of the solar array is mission critical, a highly reliable set of mechanisms is developed to provide protection during launch and at the same time a low shock release.
The ‘Stack rotation mechanism’ is considered as the most complex and most critical mechanism. This mechanism must rotate the stowed blanket stack 90° with respect to the mast. It shall provide sufficient torque to overcome the harness friction with a factor of 3, in accordance to ECSS. The mechanism is split in two parts, which puts a challenge on hinge alignment.
System Architecture
Each Flexible Compact Array wing can be divided into units, or building blocks, described under that are combined to meet the customer’s requirements on interface, power, volume, etc. The units developed in this project are highlighted:
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Photovoltaic assembly (PVA)
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Blanket module
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Harness
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Tensioning mechanism
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Pressure plates
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Secondary hold-down & release mechanism (2nd HDRM)
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Stack rotation mechanism (SRM)
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Telescopic mast
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Hold-down stack
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Root hinge
Plan
In summary the project covers the following steps:
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Definition of requirements
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Complete the conceptual design
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Preliminary design of the individual items:
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Stack Rotation Mechanism
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Secondary Holddown and Release Mechanism
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Design of a wing mock-up
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Assembly of the breadboard versions of the mechanisms
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Assembly of wing mock-up, integration of the breadboard mechanisms
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Functional testing of the breadboard mechanisms
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Design & manufacturing of the EM mechanisms
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Testing of the EM mechanisms
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Analysis of results
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Test reporting
The milestones defined for the project are: Kick-Off, Preliminary Design Review (PDR), Critical Design Review (CDR) and Final Review (FR).
Current Status
The Artes C&G project for the development of the Stack Rotation and Release Mechanisms has been completed successfully. The major achievement of this project was the integration and testing of the different (sub)-mechanisms, i.e.
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The secondary holddown and release system
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The stack rotation mechanism
Valuable experience has been gained during the assembly, integration and tests of these mechanisms and several design changes and other improvements are foreseen in the upcoming design update of these mechanisms. All key objectives of the mechanism development have been reached.
