Propellant Ambiguity for Radio-Frequency Plasma Micro-Propulsion (AMBI-RF)
Abstract
Recently, there has been a growing interest in alternative propellants for electric propulsion systems. For high-power, deep-space satellites, this search has focused on a replacement for xenon, with leading contenders being iodine and bismuth. For off-the-shelf , academic, and commercial satellites (particularly micro-satellites) the search for alternative propellants is driven by a requirement for safety, affordability, and simplicity, and includes many molecular substitutes such as ammonia, water, peroxide, ethanol, nitrous oxide, and carbon dioxide. Notably, such volatile species are also abundant in comets and asteroids, raising the possibility of In-Situ Resource Utilization (ISRU) refueling of platforms capable of extracting and employing such molecular propellants. While numerous studies have addressed the need to replace xenon, there have been significantly fewer studies into molecular propellants in electric propulsion (EP) systems. Ammonia and water in particular have not been well studied, despite presenting a storage-dense, cheap, and abundant (both terrestrially and in-situ) propellant solution for satellite operations. The proposed 3-year PhD studentship will address this shortfall in the literature by compiling a potable ammonia-nitrogen-hydrogen reaction mechanism, building upon prior work via the inclusion of vibrational ammonia and nitrogen states. Exploring how such complex vibrationally excited molecular species interact with, and alter, existing multi-harmonic and magnetized control techniques in radio-frequency driven plasmas is of critical importance to fundamental plasma science and a wide range of applications from materials processing to chemical catalysis. With specific regard to the AFOSR, this deeper understanding of power deposition and molecular dissociative pathways in RF plasma sources will facilitate a broader understanding of the pros and cons of molecular, nitrogen-containing, propellants within the high-powered air-breathing and low-to-mid powered electric propulsion environments, acting as a staging point for future studies in these areas.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 05, 2025
- Source ID
- FA86552417055
Entities
People
- Scott Doyle
Organizations
- Air Force Office of Scientific Research
- United States Air Force