Phosphonium Ionic Liquid Propellants for High-Thrust Electrospray
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Solution Overview
Problem
Current thruster propellants used in space vehicles have low mass components, resulting in low thrust levels and high electrical energy requirements, due to the specific combination of cations and anions, which limits the duration and level of thrust desired.
Innovation Solution
The use of phosphonium-based ionic liquids with high molecular mass cations as thruster propellants, which are conductive and increase the mass without significantly decreasing density, enhancing thrust generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If current propellants with low mass components are used, then the electrical energy required to produce propulsive force increases, but thrust level decreases
Solution Approach 1:
The patent changes the molecular mass parameter of the propellant components by selecting specific cations and anions. The propellant uses cations with molecular masses between 100-500 Daltons and anions with molecular masses between 50-200 Daltons, optimizing the balance between thrust generation and energy consumption by adjusting the mass parameters of the ionic components.
Solution Approach 2:
The patent creates a composite ionic liquid propellant by combining specific cations (such as phosphonium, ammonium, or sulfonium ions) with specific anions (such as halides, tetrafluoroborate, hexafluorophosphate, or bis(trifluoromethylsulfonyl)azanide). This composite approach allows optimization of both thrust level and electrical energy efficiency through the synergistic combination of ion pairs with complementary properties.
2Force
If propellant mass is increased to improve thrust, then density may decrease, but thrust level needs to be maintained or increased
Solution Approach 1:
The patent optimizes the molecular mass parameters of ionic liquid components to achieve a balance between thrust and density. By selecting cations with molecular masses of 100-500 Daltons and anions with molecular masses of 50-200 Daltons, the propellant achieves sufficient mass for high thrust while maintaining adequate density for efficient storage and operation.
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 phosphonium-based ionic liquids enable the generation of equal or higher thrust compared to previous propellants, improving the overall performance of thruster propellants by increasing mass while maintaining density.
Implementation Method 1
The disclosed thruster propellants are advantageous because they have cations that have high mass and are conductive. Thus, when used in a thruster, such propellants can generate equal or higher thrust than previous thruster propellants.
Implementation Method 2
Current electrospray thrusters typically apply an electrical charge that causes molecules of thruster propellant to be ejected from the space vehicle thus generating such propulsive force.
Implementation Method 3
Applicants prepared phosphonium-based ionic liquids with high molecular mass cations. While not being bound by theory, Applicants believe that such high mass phosphonium-based ionic liquids provide an advantage to overall thrust.
Data Source
AI summary
The present invention relates to thruster propellants, processes of making thruster propellants and space vehicles comprising thrusters that employ such propellants. The disclosed thruster propellants are advantageous because do not readily uptake water and are conductive. Furthermore, when compared to previous thruster propellants they have a higher mass, a higher density and/or a lower surface tension. Thus, when used in a thruster, such propellants can generate equal or higher thrust than previous thruster propellants.