System Design for Ammonia Nuclear Thermal Propulsion

Abstract Nuclear Thermal Propulsion (NTP) for deep space exploration is promising. Hydrogen is employed as the propellant to enhance the maximized specific impulse of NTP. Whereas, the low boiling point and density of hydrogen lead to several issues related to safety and storage. From the perspective of reactor physics, thermal hydraulics, material compatibility, and experience in the aerospace field, ammonia (NH3) is the alternative propellant to replace hydrogen. To analyze the specific impulse and system parameters of ammonia NTP, the hydrogen expander cycle NTP system analysis program PANES (Program for Analyzing Nuclear Engine Systems) is improved. The thermophysical properties library of ammonia has been increased in PANES. Based on the same thrust with hydrogen NTP, the design and analysis of ammonia NTP systems are carried out. This paper improves the PANES program and calculates the NTP performance parameters for potential alternative propellant ammonia, which provides a reference for the design of ammonia NTP system.