51 U.S.C. § 70504 — Stepping stone approach to exploration

(a) The Administration^*—(1) may conduct missions to intermediate destinations in sustainable steps, in accordance with section 20302(b) of this title, and on a schedule determined by available funding, to achieve the objective of human exploration of Mars specified in section 202(b)(5) of the National Aeronautics and Space Administration Authorization Act of 2010 (42 U.S.C. 18312(b)(5)); and (2) must include those missions in the human-exploration roadmap under section 432 of the National Aeronautics and Space Administration Transition Authorization Act of 2017. (b) To maximize the cost-effectiveness of the United States’ long-term space exploration and use activities, the Administrator^* must take all necessary steps, including working with international, academic, and industry partners, to ensure that activities in the Administration’s human space exploration program balance how they might also help meet the needs of future exploration and use activities leading to human habitation on Mars. (c) Within budgetary considerations, once an exploration-related project enters its development phase, the Administrator must seek, to the maximum extent practicable, to complete that project without undue delays. (d) To achieve the goal of successfully conducting a crewed mission to the surface of Mars, the President may invite United States partners in the ISS program and other nations, as appropriate, to participate in an international initiative led by the United States.