; (B) aerothermodynamics; (C) propulsion; (D) advanced materials and manufacturing processes; high-temperature structures and materials; and (E) flight controls. (c) Establishment of X-Plane projects (1) In general Consistent with the roadmap for supersonic research under section 604(b) of the National Aeronautics and Space Administration Transition Authorization Act of 2017 ( Public Law 115–10 ; 131 Stat. 18), the Administrator shall establish the following projects: (A) A low-boom supersonic aircraft project to demonstrate supersonic aircraft designs and technologies that— (i) reduce sonic boom noise; and (ii) assist the Administrator of the Federal Aviation Administration in enabling the safe commercial deployment of civil supersonic aircraft technology and the safe and efficient operation of civil supersonic aircraft. (B) A series of large-scale X-plane demonstrators that— (i) are developed sequentially or in parallel; and (ii) are each based on a set of new configuration concepts or technologies determined by the Administrator— (I) to demonstrate aircraft and propulsion concepts and technologies and related advances in alternative propulsion and energy; (II) to enable significant increases in energy efficiency and reduced life cycle emissions in the aviation system while reducing noise emissions; and (III) to demonstrate flight propulsion concepts and technologies. (2) Project elements For each project under paragraph (1), the Administrator shall— (A) include the development of X-planes and all necessary supporting flight test assets; (B) pursue a robust technology maturation and flight test validation effort; (C) improve necessary facilities, flight testing capabilities, and computational tools to support the project; (D) award primary contracts for design, procurement, and manufacturing to United States persons, consistent with international obligations and commitments