Long Duration Wear Test of the NASA HERMeS Hall Thruster

Abstract

Since its founding, NASA has been dedicated to the advancement of aeronautics and space science. The NASA Scientifi c and Technical Information (STI) Program plays a key part in helping NASA maintain this important role. The NASA STI Program operates under the auspices of the Agency Chief Information Offi cer. It collects, organizes, provides for archiving, and disseminates NASA's STI. The NASA STI Program provides access to the NASA Technical Report Server-Registered (NTRS Reg) and NASA Technical Report Server-Public (NTRS) thus providing one of the largest collections of aeronautical and space science STI in the world. Results are published in both non-NASA channels and by NASA in the NASA STI Report Series, which includes the following report types: • TECHNICAL PUBLICATION. Reports of completed research or a major signifi cant phase of research that present the results of NASA programs and include extensive data or theoretical analysis. Includes compilations of signifi cant scientifi c and technical data and information deemed to be of continuing reference value. NASA counter-part of peer-reviewed formal professional papers, but has less stringent limitations on manuscript length and extent of graphic presentations.

Hall Effect Thruster Impedance Characterization in Ground-based Vacuum Test Facilities

“…For instance, it may require approximately 2 to 3 hours for a 6-kW HET to achieve a steady state DC discharge current. Over the course of this time frame, the frequencies associated with important periodic phenomena, such as the breathing mode, are known to change [12]. Despite the fact that the HET is a nonlinear and time-variant load, electrical engineering methods such as small-signal impedance analysis exist to characterize the load within a small neighborhood centered around its DC operating point.…”

“…12.67 kHz indicating a potential resonant frequency although the impedance did not achieve a local maximum value. Despite this, we did not identify a discernable resonant structure that would allow us to estimate breathing mode capacitance and inductance values.…”

Optimization of the Magnetic Field Topology in the Hall Effect Rocket with Magnetic Shielding

“…The LIF measurements were performed along the discharge channel centerline, inside the discharge channel, at selected locations along the discharge chamfer region, and along selected locations on the inner and outer front pole covers. After completing the Phase I tests for configurations B1, B2 and B4, the thruster was removed from the LIF test stand, then the thruster underwent detailed surface mapping using a commercially available profilometer [22], and was then mounted on the VF6 thruster stand (shown in Fig. 12 behind the thruster).…”

“…The second wear test campaign was performed in 2017 with the TDU-3 thruster and has accumulated a total of 3,000 hours over the full throttle range of the HERMeS thruster. [20], 21,22] Figures 4 and 5 present front pole cover erosion results from the TDU-3 wear test at low background pressure. Results in Figs.…”

“…Figure 4: Inner front pole cover erosion rates from the TDU-3 wear test during thruster operation at 300 V and 6.25 kW. [22]Figure5: Outer front pole cover erosion rates from the TDU-3 wear test during thruster operation at 300 V and 6.25 kW [22]. …”