Foldable Segmented Antenna Structure for Compact Launch
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Deployable radio frequency (RF) reflector antennas for spacecraft require a foldable structure that can expand in space while being compact during launch, posing challenges in maintaining structural integrity and efficient electromagnetic energy reflection.
Innovation Solution
A foldable segmented structure comprising strut assemblies with inner and outer struts, and shell segments that articulate to form a parabolic or cylindrical shape, utilizing elastic strain energy to deploy radially and reflect electromagnetic energy effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the antenna is made large to improve ground receiver antenna discreteness, then the antenna size increases, but the antenna cannot fit inside the booster during launch
Solution Approach 1:
The antenna is divided into multiple shell segments (first shell segment, second shell segment, third shell segment, etc.) that can be folded and stowed compactly during launch, then deployed to form a large parabolic reflector in space. Each segment is rotatably connected to allow compact folding while maintaining the ability to form the complete large antenna surface area when deployed.
Solution Approach 2:
The antenna segments are designed to nest within each other during stowage, with inner segments fitting within outer segments, creating a compact cylindrical configuration that fits inside the booster. When deployed, the nested segments expand outward to form the large parabolic reflector surface.
2Volume of moving object
If the antenna is folded to fit inside the booster, then the antenna volume during launch decreases, but the structural integrity may be compromised during deployment
Solution Approach 1:
The antenna employs dynamic articulation mechanisms with rotatable connections between shell segments and strut assemblies, allowing the structure to transition from a compact stowed configuration to a deployed parabolic configuration. The dynamic joints maintain structural integrity during deployment while enabling compact stowage.
Solution Approach 2:
Different parts of the antenna structure have different properties: the shell segments provide the reflective surface with appropriate curvature, while the strut assemblies provide structural support and articulation capability. The rotatable connections at specific locations allow folding without compromising the overall structural integrity of the reflector surface.
3Strength
If the shell segments are made rigid to maintain structural integrity, then the strength increases, but the ability to fold and deploy becomes difficult
Solution Approach 1:
The rigid reflector surface is segmented into multiple shell segments that can articulate relative to each other through rotatable connections. Each segment maintains its rigid structural integrity while the assembly of segments allows folding and deployment through the articulation mechanisms at the joints.
Solution Approach 2:
The strut assemblies act as intermediary structures between the shell segments, providing the articulation mechanism that enables folding and deployment. The rotatable connections in the strut assemblies allow the rigid shell segments to move relative to each other while maintaining the overall structural integrity of the antenna.
4Volume of moving object
If the antenna is made compact for launch, then the volume during launch decreases, but the ground receiver antenna can be less discrete
Solution Approach 1:
The antenna is designed as a deployable structure that transitions from a compact cylindrical configuration during launch to a large parabolic reflector in space. The dynamic articulation mechanisms enable the antenna to achieve a large surface area (improving ground receiver antenna discreteness) while maintaining a compact volume during launch.
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 a compact, deployable RF antenna that efficiently reflects electromagnetic energy, maintaining structural integrity during deployment and stowage, and accommodating various curvature configurations for optimal performance.
Implementation Method 1
The at least one shell segment may comprise a stiffness resiliency to elastically store strain energy of the at least one shell segment in the stowed configuration. The at least one shell segment may be configured to release the stored strain energy to deploy the plurality of strut assemblies radially outward from the stowed configuration.
Implementation Method 2
The at least one shell segment may comprise a reflector surface configured to reflect electromagnetic energy to a focal region in the deployed configuration.
Data Source
AI summary
A foldable segmented structure includes a substantially center portion and a plurality of strut assemblies radially disposed around the center portion. Each strut assembly includes an inner and outer strut. The inner strut includes a first end portion rotatably coupled at the center portion and a second end portion rotatably coupled to the outer strut at an intermediate portion of the strut assembly. The intermediate portion is spaced apart from the center portion. At least one shell segment is disposed on at least one of the inner and outer strut. Each inner strut is configured to rotatably articulate about the first end portion in a first angular direction. Each outer strut is configured to rotatably articulate about the second end portion in a second angular direction opposite to the first angular direction to form an axially extending structure from the center portion to the intermediate portion in a stowed configuration.