To ensure high reliability, traditional cathode heaters undergo complex material inspections, challenging manufacturing ops, time-consuming thermal/cycle testing, onerous electrical testing, and difficult-to-assess X-ray inspections, and even after executing all of the aforementioned qualified/heritage procedures a high percentage of as-built heaters fail one of the many acceptance tests, which is costly financially, for scheduling, and from a human resource standpoint. Orbion proposes to design, test, and trade three novel heater options to simplify manufacturability without sacrificing reliability. Heater options include; 1) an integrated heater/insert using enabling/new refractory metal additive manufacturing (AM) technology, 2) an inductively heated (IH) insert which has historically been challenging due to electronics availability, and 3) an RF plasma heated insert that shares the historical electronics problem with IH tech that is no longer a problem due to the availability of space-rated integrated circuits with the appropriate frequency/power capabilities.
To achieve manufacturability, reliability, and cost-savings, each proposed heater option has inherent advantages over the incumbent (swaged) heaters, including;
The NASA applications for an innovative, reliable, manufacturable, easily inspectable heater design are far-reaching. Many of the ongoing NASA in-space propulsion programs are only possible using EP systems thus many EP systems are currently under development, e.g. AEPS, NextSTEP, and NEXT-C, all of which require hollow cathodes that use swaged heaters. The proposed efforts have the potential to serve as a risk reduction on-ramp for some of the aforementioned EP programs.
The commercial market is expanding at an unprecedented rate. The number of small sats being manufactured is far exceeding the expert projections that have been published over the past few years, and the projections showed 100s to 1000s of satellites being produced per year! Nearly all satellites being manufactured will have an EP system to meet mission requirements, which need cathode heaters.