Nanosat Electrothermal Deployment Using Resistive Burn Bar
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Solution Overview
Problem
Existing deployment systems for nanosatellites, such as those using thin coiled nichrome wiring, face issues with overheating, fusing, and breaking before reaching the nylon's melting point, and lack repeatability in deploying solar panels and antennae, which are critical for reliable operation in very small satellites.
Innovation Solution
An electrothermal deployment system utilizing a resistive element, or 'burn bar,' with a laser-etched resistor pad on an electroconductive material, which is powered to heat a fusible line to its melting point, ensuring reliable and repeatable deployment of satellite apparatus, with a configuration that minimizes weight and heat transfer to the satellite structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If thin coiled nichrome wiring is used to heat the fusible line, then the deployment system can be lightweight, but the wiring overheats, fuses, and breaks before reaching the nylon melting point
Solution Approach 1:
The patent replaces the mechanical/thin-wire heating system with a distributed resistive heating system using conductive paint or ink applied to a flexible substrate. This substitution provides more uniform heat distribution across the fusible line contact area, preventing localized overheating and wire failure while maintaining lightweight characteristics essential for nanosatellite applications.
Solution Approach 2:
The invention changes the physical parameters of the heating element from thin coiled nichrome wire to a distributed resistive layer with controlled conductivity. By adjusting the conductive material composition, layer thickness, and pattern density, the system achieves optimal heat distribution that reaches the nylon melting point reliably without exceeding temperature thresholds that cause wiring failure.
2Volume of moving object
If thin coiled nichrome wiring is used, then the structure can be compact, but the system lacks repeatability in deployment cycles
Solution Approach 1:
The patent replaces the thin coiled wire heating system with a distributed resistive heating layer on a flexible substrate. This substitution provides uniform thermal distribution that consistently melts the fusible line across multiple deployment cycles, achieving the required repeatability while maintaining compact form factor for nanosatellite constraints.
Solution Approach 2:
The invention uses composite material structures including flexible substrates with conductive paint or ink layers, combined with fusible line materials. This composite approach enables controlled thermal properties that ensure consistent melting behavior across repeated deployment cycles, addressing the repeatability requirement for satellite qualification testing.
3Temperature
If sufficient heat is applied to melt the nylon fusible line, then deployment can be achieved, but the resistive element overheats and fuses
Solution Approach 1:
The patent changes the heating element from concentrated thin wire to a distributed resistive layer, fundamentally altering the temperature distribution profile. This parameter change allows the system to reach the nylon melting temperature uniformly across the contact area without creating localized hot spots that would cause resistive element fusion or overheating.
Solution Approach 2:
The flexible substrate acts as an intermediary between the electrical power source and the fusible line. It distributes the electrical current and resulting heat uniformly across the heating zone, preventing direct concentration of thermal energy that would cause the resistive element to overheat and fail, while still achieving sufficient temperature to melt the nylon binder.
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 achieves reliable and repeatable deployment of satellite apparatus by efficiently heating the fusible line to its melting point with lower voltage requirements, reducing the risk of overheating and failure, and is designed to be reusable under test protocols, addressing the challenges of weight management and deployment reliability in nanosatellites.
Implementation Method 1
a resistive element, completed to generate heat when powered by an electrical source
Implementation Method 2
depositing a layer of electroconductive material over portions of the insulative material, providing an electrical source within the nanosat, and connecting the electroconductive material to the electrical source
Data Source
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AI summary
An electrothermal deployment system (40) may be configured for controlled release of various apparatus (20) from their prelaunch stowage positions in small satellites (10). The deployment system includes a fusible line (60) secured to a structural component (20) of the satellite, as well as to various deployable apparatus secured to, within, or on the satellite. The deployable apparatus may include items such as solar panels (20) and antennas. The deployment system includes an electrically resistive element ((42) such as a burn bar formed of a cylinder or tube, including a resistor pad (44) overlying and/or incorporated within an exterior surface of the burn bar (42). The burn bar may be coupled to an electrical circuit configured to heat the resistor for the purpose of melting the fusible line secured in direct contact therewith, thus causing the fusible line to break to cause deployment. The fusible line is configured to remain in secure contact with the resistor until apparatus deployment.