Thermal Environments and Margin Guidelines for NASA’s X-57 “Maxwell” Flight Demonstrator

NASA’s X-57 project includes development and flight demonstration of new electrified propulsion systems and equipment. The system components are designed to operate without active thermal management, which places increased emphasis on the ambient conditions as well as environmental stress screening for the newly designed equipment. Since the X-57 will not be operated outside of the Dryden Aeronautical Test Range at NASA’s Armstrong Flight Research Center, the X-57 team developed a series of reference atmospheres, described in this paper, based on the 2019 Edwards Range Reference Atmosphere to guide system development and testing. These four reference atmospheres include a standard day reference atmosphere that is identical to the 1976 U. S. Standard Atmosphere, a mean operational day atmosphere based on the mean 2019 Edwards Range Reference Atmosphere, and hot and cold day atmospheres based on the ±2σ yearly temperature variations in the Edwards Range Reference Atmosphere. As described herein, these reference atmospheres were then used to develop anticipated operational extremes for thermal cycle testing for the X-57 systems, which were developed from an amalgamation of two standards:SMC-S-016 and DO-160G. The project also adopted thermal margin guidance from SMC-S-016 to set requirements for the development of new electrified propulsion system components.