; and (2) by adding at the end the following: (b) Priority changes If scientific discoveries or external factors compel NASA to reassess decadal survey priorities, NASA shall, to the greatest extent practicable, consult with the relevant National Academies committees. . 302. Lunar discovery program (a) In general The Administrator may carry out a program to conduct lunar science research, including missions to the surface of the Moon, if that program contributes materially to the objective described in section 20102(d)(1) of title 51, United States Code. (b) Commercial landers In carrying out the program under subsection (a), the Administrator shall procure the services of commercial landers developed primarily by United States industry to land science payloads on the lunar services. (c) National Academies Lunar science research funded by the program carried out under subsection (a) shall be consistent with recommendations made by the National Academies. (d) Authorization of appropriations There are authorized to be appropriated to carry out this section— (1) $218,000,000 for fiscal year 2019, of which $18,000,000 shall be made available for the operation of the Lunar Reconnaissance Orbiter