Advanced Compatibility Characterization of AF-M315E with Spacecraft Propulsion System Materials

All spacecraft require propulsion systems for thrust and maneuvering. Propulsion systems can be chemical, nuclear, electrical, cold gas or combinations thereof. Chemical propulsion has proven to be the most reliable technology since the deployment of launch vehicles. Performance, storability, and handling are three important aspects of liquid chemical propulsion. Bipropellant systems require a fuel and an oxidizer for propulsion, but monopropellants only require a fuel and a catalyst for propulsion and are therefore simpler and lighter. Hydrazine is the state of the art propellant for monopropellant systems, but has drawbacks because it is highly hazardous to human health, which requires extensive care in handling, complex ground ops due to safety and environmental considerations, and lengthy turnaround times for reusable spacecraft. All users of hydrazine monopropellant must contend with these issues and their associated costs. The development of a new monopropellant, intended to replace hydrazine, has been in progress for years.

This project will apply advanced techniques to characterize the engineering properties of materials used in AF-M315E propulsion systems after propellant exposure. AF-M315E monopropellant has been selected HQ’s Green Propellant Infusion Mission (GPIM) to replace toxic hydrazine for improved performance and reduce safety and health issues that will shorten reusable spacecraft turn-around time. In addition, this project will fundamentally strengthen JSC’s core competency to evaluate, use and infuse liquid propellant systems.

This project will apply advanced techniques to characterize the engineering properties of materials used in AF-M315E propulsion systems after propellant exposure. AF-M315E monopropellant has been selected by NASA HQ’s Green Propellant Infusion Mission (GPIM) to replace toxic hydrazine for improved performance and reduce safety and health issues that will shorten reusable spacecraft turn-around time.

The compatibility of propulsion system materials with AF-M315E is not well characterized and a specification for the propellant has not been finalized. The corrosion and degradation properties of materials available to design engineers will be examined and corrosion/degradation will be reduced by surface modification. This work will provide data for the selection and improvement of candidate materials used in AF-M315E spacecraft propulsion systems with potential applications to ground support equipment and an improved propellant specification.

WSTF has developed and used in previous work the infrastructure and experience to perform the tests which AF-M315E’s classification as an explosive requires.

The goal of this project is to provide enhanced material and fluid compatibility data for designers to build spacecraft and GSE with a higher degree of confidence. In addition, a specification suitable for characterizing the fluid will be provided. The compatibility of propulsion system materials with AF-M315E is not well characterized, there is little information in the literature, and few entities have performed material and fluid compatibility testing. In addition, this project will fundamentally strengthen JSC’s core competency to evaluate, use and infuse liquid propellant systems.