Propellant management device in space: feasibility study for an infrared heating control system

Traineeship experience has been done at T4i, Technology for Propulsion and Innovation S.P.A. The main business of the company is researching and developing innovative space propulsion systems to serve small satellite platforms. Thrusters done by T4i are divided mainly into two class: chemical thrusters and electrical thrusters. Electric motor generates thrust ionising the propellant that has to arrive in the ionisation chamber in gas phase; they could store and utilized two different types of fuel: noble gasses such as Xenon, Argon, or Krypton, or solid materials such as Iodine, chosen because is capable of sublimation, so in the phase change, liquid phase could be avoid. Research activity showed in the following thesis has been done with the purpose of improving electrical engines founding a better way to interact with the solid propellant. Both types of fuels have positive and negative aspects solid fuels has an easier storage, and an higher density compare to noble gasses, and this results in a higher mass with the same volume, but it is necessary to induce a phase-change, from solid to gas, inside the storage tank, on the other hand, noble gasses do not need phase-change but they have to be stored at high pressure to obtain a significant amount of mass, and as a consequence, they need an appropriate fluidic line. The main limitation of these types of thrusters is that, in space fly operations, there is a limited amount of power, especially in small satellites, so, improve the way this power is used results in a higher global efficiency. In this moment, in solid electrical motor, phase change is provided by heating all the mass of the fuel inside the tank, to use less power and to have a better conservation of the propellant, heating could be done by infrared radiation. IR should heat and induce sublimation only on the surface of the solid material, emission is carried out using specific materials with high emissivity. Aim of the research is to demonstrate that this new way of heating is more convenient than the traditional one. In order to do this, it is important to ensure before, that IR effectively induce sublimation. During traineeship project, an experimental set-up has been thought and built, with the scope of studying the interaction between IR and a material which simulate the behaviour of Iodine, in this specific case, naphthalene. The experiment focus is the variation of pressure inside a chamber where is placed a sample of sublimating element. Chamber could be surrounded by two different emitters, one made of low emission material, and the other made of high emission material; it is expected that the variation of pressure results bigger when high emission material is used, this would indicate that IR effectively induce sublimation on the substance contained in the chamber. All the design and experimental activities have been made inside T4i laboratories at CISAS “Centro di Ateneo di Studi e Attività Spaziali Giuseppe Colombo”.