BN Ceramics for Hall-Effect Thruster Discharge Channels

Both NASA#39;s Science Mission Directorate (SMD) and Human Exploration and Operations Mission Directorate (HEOMD) need spacecraft with demanding propulsive performance and greater flexibility for more ambitious missions requiring high duty cycles and extended operations under challenging environmental conditions. Planetary spacecraft need the ability to rendezvous with, orbit, and conductnbsp;in situnbsp;exploration of planets, moons, and other small bodies.nbsp; For these applications, Hall Effect thrusters are being designed to meet the propulsion need.nbsp;nbsp;Current Hall effect thrusters make use of hexagonal boron nitride (BN) for the discharge channel in which plasma is generated and accelerated. However, the BN materials have exhibited substantial lot-to-lot variability. Such material property inconsistencies have thus necessitated costly thruster design features to improve survivability margins against mechanical and thermal shock.nbsp;ACM has developed PAL BN materials that will reduce the causes of variability and offer predictable performance. ACMrsquo;s PAL technology produces a highly uniform microstructure with significant improvements in mechanical properties.