Fiber-fed Pulsed Plasma Thruster for CubeSat Delta-V
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Classic pulsed plasma thruster technology is limited by its high mass and small propellant load, making it unsuitable for precision pointing and small delta-V applications, and lacks the capability for primary propulsion such as orbit change and de-orbiting.
Innovation Solution
The Fiber-fed Pulsed Plasma Thruster (FPPT) uses a motor-driven fiber feed system and a highly parallel ceramic capacitor bank to increase propellant throughput and reduce system specific mass, enabling higher impulse performance with a non-pressurized, inert Teflon propellant.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If classic pulsed plasma thruster is used, then attitude control and precision orbital adjustments are achieved, but total impulse capability is limited for primary propulsion applications
Solution Approach 1:
The propellant is segmented into discrete Teflon fiber elements that are fed individually through the anode, allowing controlled ablation and plasma generation for each pulse while maintaining high total impulse capability through cumulative fiber consumption
Solution Approach 2:
The system dynamically adjusts propellant feed rate and pulse frequency to optimize between precision control mode (lower feed rate, higher precision) and high impulse mode (higher feed rate, greater total impulse), resolving the contradiction between precision and total impulse capability
2Quantity of substance
If propellant load is increased for primary propulsion, then total impulse is improved, but system mass increases
Solution Approach 1:
The system replaces traditional mechanical propellant storage (pressurized tanks, solid blocks) with a motor-driven fiber feed system that delivers propellant on demand, reducing the mass of storage infrastructure while maintaining high total impulse capability through efficient fiber consumption
Solution Approach 2:
The system changes the physical state and delivery mechanism of propellant from bulk storage to fiber-form continuous feed, allowing high propellant mass to be delivered with minimal storage mass, thereby improving total impulse without proportionally increasing system mass
3Quantity of substance
If propellant storage capacity is increased, then total impulse per unit volume is improved, but thruster volume increases
Solution Approach 1:
The system extracts the propellant storage function from the thruster volume by using a motor-driven fiber feed system where propellant is stored externally and delivered through a narrow feed channel, allowing high propellant capacity without increasing thruster envelope volume
Solution Approach 2:
The system transitions from three-dimensional bulk propellant storage to one-dimensional fiber feed, where propellant is delivered as a linear element through the anode, dramatically increasing propellant density per unit thruster volume while maintaining compact dimensions
4Object-affected harmful factors
If Teflon propellant is used, then range safety concerns are eliminated, but propellant feed mechanism complexity increases
Solution Approach 1:
The Teflon fiber propellant is self-fed through the anode by motor-driven tension, eliminating the need for complex pressurization systems, valves, or flow control mechanisms, thereby reducing overall system complexity despite the inert nature of Teflon requiring careful handling
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
FPPT achieves a significant increase in total impulse per unit volume, enabling delta-V capabilities of up to 1.4 km/s for small satellites, while reducing system mass and cost, and eliminating range safety concerns due to the inert propellant.
Implementation Method 1
ignite a primary high current, high magnetic field discharge between the anode and cathode thereby creating a plasma that vaporizes the fiber propellant
Implementation Method 2
vaporizes the fiber propellant at the exit end
Implementation Method 3
create a partially ionized gas electromagnetically and electrothermally accelerated outward from the nozzle region to produce the jxB thrust
Implementation Method 4
The capacitor bank is configured to lower an equivalent series resistance that raises a pulse current
Implementation Method 5
A stepper motor in communication with the fiber propellant is provided to pull the fiber propellant from the spool
Data Source
AI summary
A Fiber-fed Pulsed Plasma Thruster (FPPT) utilizes a motor to feed PTFE fiber to its discharge region, enabling high PPT propellant throughput and variable exposed fuel area. A highly parallel ceramic capacitor bank lowers system specific mass. Impulse bits (I-bits) from 0.057-0.241 mN-s have been measured on a thrust stand with a specific impulse (Isp) of 900-2400 s, representing an enhancement from state-of-the-art PPT technology. A 1 U (10 cm×10 cm×10 cm, or 1 liter) volume FPPT thruster package will provide 2900-7700 N-s total impulse, enabling 0.6-1.6 km/s delta-V for a 5 kg CubeSat. A 1 U design variation with 590 g propellant enables as much as ˜10,000 N-s and a delta-V of 2 km/s for a 5 kg CubeSat. Increasing the form factor to 2U increases propellant mass to 1.4 kg and delta-V to 10.7 km/s for an 8 kg CubeSat.