Recent electric propulsion development activities for NASA science missions

Abstract

Abstract(The primary source of electric propulsion development throughout NASA is managed by the In-Space Propulsion Technology Project at the NASA Glenn Research Center for the Science Mission Directorate. The objective of the Electric Propulsion project area is to develop near-term electric propulsion technology to enhance or enable science missions while minimizing risk and cost to the end user. Major hardware tasks include developing NASA's Evolutionary Xenon Thruster (NEXT), developing a long-life High Voltage Hall Accelerator (HIVHAC), developing an advanced feed system, and developing crossplatform components. The objective of the NEXT task is to advance next generation ion propulsion technology readiness. The baseline NEXT system consists of a highperformance, 7-kW ion thruster; a high-efficiency, 7-kW power processor unit (PPU); a highly flexible advanced xenon propellant management system (PMS); a lightweight engine gimbal; and key elements of a digital control interface unit (DCIU) including software algorithms. This design approach was selected to provide future NASA science missions with the greatest value in mission performance benefit at a low total development cost. The objective of the HIVHAC task is to advance the Hall thruster technology readiness for science mission applications. The task seeks to increase specific impulse, throttle-ability and lifetime to make Hall propulsion systems applicable to deep space science missions. The primary application focus for the resulting Hall propulsion system would be cost-capped missions, such as competitivelyselected, Discovery-class missions. The objective of the advanced xenon feed system task is to demonstrate novel manufacturing techniques that will significantly reduce mass, volume, and footprint size of xenon feed systems over conventional feed systems. This task has focused on the development of a flow control module, which consists of a three-channel flow system based on a piezo-electrically actuated valve concept, as well as a pressure control module, which will regulate pressure from the propellant tank. Cross-platform component standardization and simplification are being investigated through the Standard Architecture task to reduce first user costs for implementing electric propulsion systems. Progress on current hardware development, recent test activities and future plans are discussed.

Dual-Mode Propellant Properties and Performance Analysis of Energetic Ionic Liquids

“…The system efficiency is arbitrarily selected as representative of what current electrospray systems might be capable of, considering the relative immaturity of the technology, [2][3][4] and that current hall thruster systems are roughly 50% efficient. 57 Similarly, current electrospray technology has demonstrated current levels of up to 1 µA with a single emitter. Improvements in the current electrospray technology level will affect all propellants the same, 2-4 provided it is not the physical properties of the propellant that drive the technology improvement; therefore, for this analysis it is prudent to use constant system parameters with respect to estimated current technology levels.…”

Performance and Environmental Test Results of the High Voltage Hall Accelerator Engineering Development Unit

“…NASA SMD's In-Space Propulsion Technology Project (ISPT) funds new EP system development for future NASA science missions. 7 The two primary EP elements of this project are the development of NASA's Evolutionary Xenon Thruster (NEXT) ion thruster propulsion system 8 for NASA Flagship, New Frontiers and Discovery class missions and the development of a long-life High Voltage Hall Accelerator (HiVHAc) 9 as a lower cost EP option for NASA Discovery class science missions.…”

Doubly‐Charged Xe Ions Evidenced by Time Resolved RPA Measurement in the Far Field Plume of a Low‐Power HET

“…Nowadays, HET thrusters are developed worldwide [2][3][4], due to their increasing use in satellite's orbit keeping. Recently, the SMART1 lunar mission of the European Space Agency demonstrated their long term reliability in the power domain 1 to 1.5 kW.…”

“…This HET technology benefits from the experience acquired in the former USSR and Russia where the first test in space was achieved as early as 1972 [1] on board a meteorological satellite. Nowadays, HET thrusters are developed worldwide [2][3][4], due to their increasing use in satellite's orbit keeping. Recently, the SMART1 lunar mission of the European Space Agency demonstrated their long term reliability in the power domain 1 to 1.5 kW.…”