Low-power Hall effect thrusters (HETs) belong to a class of electric thrusters with an operating power lower than 500 W. The application of this class of HETs is suited for small satellites for telecommunications and Earth observation missions. Sitael is active in this field, through the development of two HETs, HT100, and HT400, belonging to a power class of 100 and 400 W, respectively. HT100 is a permanent-magnet thruster operating in the 100- to 250-W range, providing thrust between 4 and 13 mN, and specific impulse between 900 and 1400 s. HT400 operates in the 350- to 750-W range, providing thrust between 20 and 45 mN, and specific impulse between 1300 and 1700 s. Two cathodes have been developed and tested, referred to as HC1 and HC3, conceived for HT100 and HT400, respectively. Both cathodes are based on Sitael heritage in theoretical modeling and experimental activities for the development of such devices, and rely on lanthanum hexaboride emitters. HC1 is a cathode designed to provide a discharge current in the 0.3-1 A range, operating in steady-state conditions at mass flow rates between 0.08 and 0.5 mg/s of xenon. HC3 was designed for the range 1-3 A of discharge current, with 0.08-0.5 mg/s of mass flow rate. Both HC1 and HC3 have an expected lifetime higher than 10⁴ h, based on the rate of material evaporation from the emitter surface, computed with the aid of a theoretical model developed to guide the cathode design. Experiments were carried out, including preliminary characterization campaigns, of each of the two cathodes and HET-cathode coupling tests. The collected data are presented and discussed with reference to the model predictions, showing a good agreement between theoretical and experimental results

SITAEL is active in the field of electric propulsion and is involved in the development of different thruster technologies—mainly Hall thrusters (HTs)—of power levels ranging from 100 W up to 20 kW. Low-power HTs are the most effective choice to perform orbit transfer, drag compensation, and de-orbiting maneuvers for small satellites. This paper is dedicated to the activities regarding HC1, the hollow cathode conceived for the 100-W-class Hall thruster under development at SITAEL. Successful test campaigns were performed and are described, with emphasis on the improvements in the cathode design after an extensive research and development phase. The results are presented and discussed, along with future developments of the ongoing activities.

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