Experimental Testing of Electrothermal Microthrusters with Autonomous Heating Elements for Orbital Maneuvering of Small Space Vehicles

Background/Objectives: The paper considers the results of the experimental tests on Electrothermal Microthrusters (ETMT) with Autonomous Heating Elements (AHE) of various designs for Corrective Propulsion Systems (CPS) of maneuverable Small Space Vehicles (SSV). The experimental tests are of major importance for developing ETMT with AHE and of particular interest for designing CPS for maneuverable SSVs, including ultralight SSVs (under 10 kg). Method: The design parameters have been determined and the experimental ETMTs of four different designs have been manufactured using the multipurpose structural design method. Among them, ETMT with AHE, ETMT with AHE having a combined thruster-evaporator circuit, ETMT with AHE having a combined thruster-evaporator circuit and a possibility for connection of external devices, as well as ETMT with AHE having a combined thruster-evaporator circuit and an integrated throttle. Findings: The experimental ETMTs meet the minimum weight and size requirements and are capable of generating a high specific impulse while consuming little electrical power. The paper looks at the results of the ground tests, including the tests in a vacuum chamber with liquid gasified ammonia and nitrogen used as operating gases. The tests have proven that ETMT with AHE can operate at 5 to 70 W as part of SSV CPS. The recommendations have been given with regard to the use of ETMTs with AHEs as part of SSVs with different weight characteristics, as well as the amount of electrical power required for CPS operation.