Power Efficient Pulsed Plasma Thruster with Precise Control of High Voltage Generation
Session
Pre-Conference: CubeSat Developers' Workshop
Abstract
The lifetime of LEO (Low Earth Orbit) Nanosatellites and CubeSats is currently limited by their susceptibility to natural de‐orbiting. An appropriately scaled pulsed plasma thruster offers the most adaptable technological solution to this problem by compensating for atmospheric drag. This technology can be used to aid the spacecraft de‐orbiting to comply with the 25 years de‐orbiting guidelines. A PPT consists of a pair of electrodes separated by a propellant bar than can be fed either from the side or from the breech of the electrodes. The electrodes are connected to a main capacitor bank charged to a voltage of the order of 1‐2kV and storing energy of some joules. To operate the thruster a high voltage pulse (5‐10kV) is sent to a spark plug. This triggers a discharge between the two main electrodes that ablates some of the propellant, ionizes it, and expels it to high velocity generating thrust. The design of the electronics and the thruster head of the nanosat and CubeSat PPT have evolved over time based on tests and experiments during several test campaigns. Inherent constraints such as small size and limited power budget of this type of satellites have been overcome by the use of the proposed topology. Previous designs use voltage multipliers for high voltage generation in the ignition circuit. These circuits provide a very simple way of generating the high voltage needed for such circuit. However the repeatability of the high voltage pulse event it is not precisely controlled. The following paper presents a new topology used for the electronics of the PPT that brings the following advantages with respect to other topologies used: lower power consumption achieved by the use of a pre‐charged stage before all the energy is released into the high voltage stage, better control of the power consumption; a more accurate control of the firing process; and a smaller size. These characteristics allow the use of the same circuit to provide the high energy to be stored between the anode and the cathode of the chamber and for the ignition circuit, thus simplifying the design and test of the overall system. The results presented in this paper show that the design proposed provides lower power consumption and a more precise control of the ignition process compared to previous designs. The proposed design is also scalable to be used in thrusters for bigger satellites offering the previously cited advantages.
Presentation Slides
Power Efficient Pulsed Plasma Thruster with Precise Control of High Voltage Generation
The lifetime of LEO (Low Earth Orbit) Nanosatellites and CubeSats is currently limited by their susceptibility to natural de‐orbiting. An appropriately scaled pulsed plasma thruster offers the most adaptable technological solution to this problem by compensating for atmospheric drag. This technology can be used to aid the spacecraft de‐orbiting to comply with the 25 years de‐orbiting guidelines. A PPT consists of a pair of electrodes separated by a propellant bar than can be fed either from the side or from the breech of the electrodes. The electrodes are connected to a main capacitor bank charged to a voltage of the order of 1‐2kV and storing energy of some joules. To operate the thruster a high voltage pulse (5‐10kV) is sent to a spark plug. This triggers a discharge between the two main electrodes that ablates some of the propellant, ionizes it, and expels it to high velocity generating thrust. The design of the electronics and the thruster head of the nanosat and CubeSat PPT have evolved over time based on tests and experiments during several test campaigns. Inherent constraints such as small size and limited power budget of this type of satellites have been overcome by the use of the proposed topology. Previous designs use voltage multipliers for high voltage generation in the ignition circuit. These circuits provide a very simple way of generating the high voltage needed for such circuit. However the repeatability of the high voltage pulse event it is not precisely controlled. The following paper presents a new topology used for the electronics of the PPT that brings the following advantages with respect to other topologies used: lower power consumption achieved by the use of a pre‐charged stage before all the energy is released into the high voltage stage, better control of the power consumption; a more accurate control of the firing process; and a smaller size. These characteristics allow the use of the same circuit to provide the high energy to be stored between the anode and the cathode of the chamber and for the ignition circuit, thus simplifying the design and test of the overall system. The results presented in this paper show that the design proposed provides lower power consumption and a more precise control of the ignition process compared to previous designs. The proposed design is also scalable to be used in thrusters for bigger satellites offering the previously cited advantages.
