14 CFR 91.331: Space support vehicle flights: Operating limitations.

(a) A person may operate an aircraft to conduct a space support vehicle flight carrying persons or property for compensation or hire provided—

(1) The aircraft has a special airworthiness certificate issued under § 21.191 of this chapter.

(2) The aircraft conducting the space support vehicle flight—

(i) Takes flight and lands at a single launch or reentry site that is operated by an entity licensed to operate the launch or reentry site under 51 U.S.C. chapter 509;

(ii) Is owned or operated by a launch or reentry vehicle operator licensed under 51 U.S.C. chapter 509, or on behalf of a launch or reentry vehicle operator licensed under 51 U.S.C. chapter 509;

(iii) Is a launch vehicle, a reentry vehicle, or a component of a launch or reentry vehicle licensed for operations pursuant to 51 U.S.C. chapter 509; and

(iv) Is used only to simulate space flight conditions in support of—

(A) Training for potential space flight participants, government astronauts, or crew (as those terms are defined in 51 U.S.C. chapter 509);

(B) The testing of hardware to be used in space flight; or

(C) Research and development tasks, which require the unique capabilities of the aircraft conducting the flight.

(b) The Administrator may prescribe additional operating limitations that the Administrator considers necessary in the interest of safety.