Investigation of low-energy PPT's for CubeSat's
2018 (English)Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE credits
Student thesis
Abstract [en]
The Pulsed Plasma Thruster (PPT) is the oldest type of electric propulsion, as the first was sent into spacein 1964. However, this technology was mostly abandoned in the subsequent decades, with more efficient electric propulsion technologies having been developed. In parallel with the rise in popularity of nanosatellites, the last two decades have sparked a growing interest for this type of propulsion due to its apparent simplicity, low cost and easy-scalability in terms of size and power. This work offers a preliminary investigation of a low-energy PPT for an eventual integration in a CubeSat. A comprehensive literature review on PPT’s provides an overview over the wealth of information that has been gathered over the past five decades. A short literature review of CubeSat’s, their history, advantages, limitations and subsystems introduces the subject to allow for a design process tailored on CubeSat’s needs. A subsequent market analysis of Attitude Control Systems (ACS) and already designed PPT’s for CubeSat allows to envision apotential future PPT for attitude control and drag compensation that could be marketable. After an overview of past PPT research done at the National Cheng Kung University in Taiwan, experiments were conductedon sub-1J PPT’s. Long term tests were performed and allowed to see the limitations of the design of the sparkplug. Measurements of the eroded mass to determine the eroded mass per discharge were attempted but were unsuccessful due to insufficient resolution of the balance. A new set of electrodes was designed and the Impulse-bit, analogous to thrust-per-pulse, of all set electrodes were measured using a semi-empirical formula. A significant novelty was the attempted use of Quartz instead of PTFE between theelectrodes, which resulted in successful discharges without performance decrease compared to the equivalent PTFE PPT. This yields the promise to mitigate the problem of carbon-coating in the discharge chamber. However, it remains unclear if the presence of PTFE in the sparkplug may have been a significant source of the plasma and thus would have compensated for the lack of PTFE in-between the electrodes. Future research will have to determine if similar performance figures can be achieved even without the presence of PTFE in the sparkplug, as well as investigate if the erosion rate of the sparkplug is higher when Quartz is used.
Place, publisher, year, edition, pages
2018. , p. 133
Keywords [en]
Pulsed Plasma Thruster, PPT, electric propulsion, microsatellite, attitude control
National Category
Aerospace Engineering
Identifiers
URN: urn:nbn:se:ltu:diva-71568OAI: oai:DiVA.org:ltu-71568DiVA, id: diva2:1263249
External cooperation
ODYSSEUS SPACE Inc.
Subject / course
Student thesis, at least 30 credits
Educational program
Space Engineering, master's level (120 credits)
Supervisors
2018-11-152018-11-142018-11-15Bibliographically approved