The propulsion subsystem is necessary to generate thrust and make adjustments to both the satellite's trajectory and its attitude. A general propulsion system will use a propellant tank, plumbing, control devices, and nozzles or thrusters to provide the necessary thrust for a given satellite's mission. A propulsion system is critical to ensure that the spacecraft has maneuverability while in its orbit, and can make necessary adjustments to correct any anomalies that may occur during deployment or later stages of flight.
Nanosat-8 utilizes a novel cold-gas propulsion system that, when it was initially designed, was a pioneer in its field. The choice to use a cold-gas was decided mainly on the fact that the traditional methods (Hydrazine) were too dangerous, and an alternative, safer approach was desired. The propellant chosen to satisfy this requirement was R-134a, a common household refrigerant, that was readily available, inexpensive, and provided adequate theoretical results for what was required of the spacecraft.
Nanosat-9's primary payload will be the propulsion system, which will utilize an innovative multi-mode configuration with a single monopropellant that has the ability to toggle between chemical combustion and electric propulsion. This type of system would allow for much more mission capability and flexibility while in orbit.