51 U.S.C. § 70103

(a) Definitions .— In this section: (1) Launch vehicle .— The term “launch vehicle” means any vehicle constructed for the purpose of operating in, or placing a payload in, outer space. (2) Payload .— The term “payload” means an object which a person undertakes to place in outer space by means of a launch vehicle, and includes subcomponents of the launch vehicle specifically designed or adapted for that object. (b) In General .— Commercial payloads may not be accepted for launch as primary payloads on the space launch system unless the Administrator determines that— (1) the payload requires the unique capabilities of the space launch system; or (2) launching of the payload on the space launch system is important for either national security or foreign policy purposes.