Liquid Micro Pulsed PlasmaThruster for nanosatellites (L-μPPT)

The rapid emergence of new application domains and mission types, both in the scientific and commercial segments, has had a large impact on the evolution of spacecraft design. In many cases, the narrow focus and small footprint of many modern payloads motivates the development of smaller and lighter platforms. The design and conception of next generation launch vehicles accounts for this trend and attempts to meet the new demand for  microspacecrafts.

The current interest for micro-spacecrafts essentially proceeds from the wider availability of enabling technologies (micro/nano-fabrication), and from the desire to reduce development and launcher costs. Nanosatellites are also potentially useful as a mean to increase a mission's reliability by distributing a large payload over a fleet of small spacecrafts. However, the  application range of micro-spacecraft is currently restricted by the lack of sufficiently compact, lightweight, high specific impulse micro-propulsion systems. Such micro-propulsion system could also prove useful for fine positioning required by space-based telescope interferometers, imaging arrays and formation flying missions.

The present project consists in a lightweight, low complexity electric propulsion system based on an innovative Liquid-propellant Micro Pulsed Plasma Thruster (L-μPPT) to address the electric propulsion needs of class II microspacecrafts (1-5kg).

Due to their simplicity, reliability, scalability and low weight, Pulsed Plasma Thrusters (PPT) are currently considered the most suitable option for small delta-V missions on nanosatellites. PPTs are electromagnetic propulsion devices which store electrical energy in a capacitor to periodically form a high current arc discharge across the propellant (typically Teflon). The most common PPT technology is the solid propellant technology, where the propellant is a block of teflon. Its big advantage is extreme simplicity, its disadvantages are low efficiency and variation of impulse bit through lifetime.

Nevertheless L-μPPT project intends to use PPT technology which uses a liquid propellant, which allows the amount of propellant introduced (and thus the impulse bit) to be tightly controlled, and also allows larger efficiencies.