Pulsed Plasma Thrusters (PPTs) are long-standing, space-qualified electric propulsion thrusters of proven reliability, relatively simple and low-cost. Their compactness, robustness and scalability are increasingly appealing, as the space industry interest in small satellites grows all over the world. A Pulsed Plasma Thruster for CubeSat Propulsion PPTCUP has been developed in collaboration with Clyde Space Ltd, which is responsible for the design of the power supply and the University of Southampton.
A full flight qualification program has been completed. The PPTCUP Qualification Model (QM) successfully passed EMC, vibration, thermo-vacuum testing and lifetime
PPTCUP-QM performance are:
Thanks to its performances PPTCUP is suitable to a range of missions including drag compensation, orbit keeping, formation flying and small orbit transfer. PPTCUP can also be used as a de-orbiting device in cases where the spacecraft will not be compliant with the 25 year de-orbiting rule. Lowering of the orbit perigee up to 40 km on a 3U cubesat can be achieved and proportionally more on 2U and 1U Spacecrafts
In 2015 a numerical model developed by Mars Space and the University of Southampton was used to optimize the PPTCUP thruster head. The most promising configurations obtained from the PPTCUP design by changing the electrodes shape, the electrode separation distance and the propellant thickness were built and tested. The configuration that according to the model can deliver the highest total impulse was found to be the best also during the experimental test campaign.
This second generation of PPTCUP can deliver a total impulse of 67.3±6.2 Ns, hence about 65% higher than the one that PPTCUP-QM proved to be able to deliver. This is a significant improvement in performance that can be potentially obtained without changing the already qualified conditioning electronics and capacitor bank, since the power requirement and the shot energy have not been changed.
One current trend in space technology is towards miniaturisation of spacecraft, from mini to micro, pushing towards nanosats. In this frame, mission types that could benefit from the miniaturisation of satellites and the use of a micro-thruster module have been investigated, and Pulsed Plasma Thrusters, is the technology which can best meet the full range of their requirements or at least best meet them over the widest range.
A modular NanoPPT thruster system has been developed to be integrated and customized to accommodate different nano-satellites mission requirements. A study case scenario has been selected and used to demonstrate the potential application that the NanoPPT module could provide to a nanosatellite.
The goal of the activity is to develop a 6 NanoPPT propulsion system to perform station keeping and attitude control manoeuvres (ΔV=40m/s, Total Impulse=800Ns). The system was built and tested in collaboration with Clyde Space Ltd and the University of Southampton.
A breech-fed geometry has been selected in order to reduce accommodation issues without compromising cost savings associated to modularity, integration capability and short development/manufacturing schedule.
The breadboard model of the NanoPPT has been successfully developed and tested, with the following performance: