Reconfigurable Hold-Down Assembly for Spacecraft Reflector Deployment
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Solution Overview
Problem
Spacecrafts face challenges in reconfiguring from launch to on-orbit configurations while maintaining compatibility with conventional launch vehicles and ensuring secure attachment of multiple large reflectors to prevent motion in all degrees of freedom during launch and allow controlled deployment in space.
Innovation Solution
A reconfigurable hold-down assembly system that transitions from a fully engaged configuration to a partially engaged configuration, allowing a manipulator to move reflectors from a stowed to a deployed position while preventing drift and rotation except along a specific axis, ensuring secure attachment during launch and controlled deployment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the hold-down assembly is in fully engaged configuration to prevent motion in all six degrees of freedom, then the reflector is securely attached during launch, but the reflector cannot be moved to deployed position
Solution Approach 1:
The hold-down assembly is designed with dynamic reconfigurability, transitioning from a fully engaged configuration that prevents motion in all six degrees of freedom to a partially engaged configuration that permits movement along the first direction. This dynamic adaptation allows the same structure to serve both secure attachment during launch and controlled deployment in space
Solution Approach 2:
The constraints on the reflector are segmented by direction - the hold-down assembly selectively prevents motion in five degrees of freedom while permitting movement in the first direction (along the long axis of the housing). This directional segmentation enables both secure attachment and controlled deployment through the same structure
2Adaptability or versatility
If the hold-down assembly permits movement in the first direction for deployment, then the reflector can be repositioned to on-orbit configuration, but the reflector may drift or rotate uncontrollably
Solution Approach 1:
The hold-down assembly provides different constraint qualities in different directions: it permits free movement along the first direction (long axis of housing) for deployment while maintaining restrictive constraints in all other directions. This local differentiation of constraint quality enables controlled deployment without uncontrolled drift or rotation
3Productivity
If multiple reflectors with increased aperture size are used to meet payload capacity requirements, then the spacecraft performance is improved, but the complexity of securing and deploying these reflectors increases
Solution Approach 1:
The hold-down assembly is designed as a universal attachment mechanism that can secure multiple reflectors of different sizes using the same basic structure. The assembly performs multiple functions: securing reflectors during launch, enabling controlled deployment, and maintaining stability in on-orbit configuration. This multi-functionality reduces overall system complexity despite increased payload requirements
Data Source
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AI summary
A spacecraft, reconfigurable from a launch configuration to an on-orbit configuration, includes a main body structure (111), a manipulator(140), a first deployable rigid reflector (120) and an attachment arrangement (130), including at least one hold-down assembly (HDA). In the launch configuration, the HDA is in a fully engaged configuration such that the attachment arrangement mechanically attaches the first reflector (120) with the spacecraft main body structure (111) and prevents relative motion between the first reflector (120) and the spacecraft main body (111). Reconfiguring the spacecraft from the launch configuration to the on-orbit configuration includes (i) actuating the HDA from the fully engaged configuration to a partially engaged configuration; (ii) grasping and moving the first reflector, with the manipulator, a distance in the first direction; and (iii) moving the first reflector from a first position proximate to the attachment arrangement to a second position proximate to a deployed position associated with the on-orbit configuration.