Due to the ambitiousness of this new campaign, NASA has some planned milestones, but also recognizes that they will need to make some critical decisions as to how to focus its energies, as the program progresses and they learn from their previous successes and, with good fortune, rare failures.

Critical Decisions and Milestons:

Lunar Orbit

2018:

• Decision to develop the Gateway, commercial and international partnerships, and final configuration. The Gateway also will provide broad science research and technology demonstration opportunities from cislunar space, in areas including lunar surface (e.g., lunar sample return, tele-robotics, etc.), astrophysics, heliophysics and Earth science.

2019:

• Determine appropriate Gateway requirements and then, based on those, orbitalparameters. A key consideration will be affordability (i.e., Gateway can be visited by multiple launch vehicles).

2020:

• SLS/Orion EM-1, uncrewed, to the lunar vicinity.

• Initiate scientific payload development for Gateway by competitively assessing the most suitable and impactful scientific analysis.

• Science and industry missions flown on EM-1 using 13 co-manifested CubeSats launched as secondary payloads.

• Decision on acquisition approach for remaining elements of Gateway (complete by 2021).

• Based on status of launch vehicle development, decide on future Gateway logistic resupply missions

2022:

• By June, conduct crewed flight, EM-2, sending Americans around the Moon.

• First element of Gateway, the power-propulsion (including communications) element (PPE), placed in lunar orbit.

2024:

• Based on status of crew capsule development and operations, decide on need for further investments to increase options for return to Earth from lunar orbit

Post 2024 Decisions:

• Based on human lunar surface return plans and scope, and decision on human Mars orbital mission architecture for the 2030s, determine need for, and viability of, developing and placing propellant depots in lunar orbit. Assess and make appropriate decisions on Gateway evolution requirements.

Lunar Surface

2018:

• Decision to procure commercial lunar payload services for NASA starting as early as 2019

• Establish the Lunar Discovery and Exploration Program in SMD. This initiative will feature several programs, including Commercial Lunar Payload Services (funding for end-to-end delivery of payloads to the lunar surface starting in 2020).

• Decision on potential missions to focus on lunar resources and other scientific discoveries, including mobility and sample return capabilities.

2019:

• Make early decisions on architecture of lunar exploration program.

• Decision on a date for a demonstration mission for human-class lunar lander capability.

• Decision to begin human lunar surface architecture and mission analyses to support

• Americans on the lunar surface no later than 2029.

2020:

• Based on early results of human-class lunar lander development and human lunar surface architecture analyses, begin capability stimulation, development and/or procurement of other elements required for human lunar surface return (e.g., human cabin and ascent vehicle, retro-braking stage, extended Orion service module).

2021:

• Based on results of commercial services for NASA lunar payloads, plan to either procure commercial launch services for a second resource and science rover mission or conduct mission development and operations in-house.

2022:

• Based on results of 2022 NASA lunar resource and science rover mission, plan to either accelerate development of ISRU systems and partnerships, or maintain baseline R&D effort

2024:

• Based on results of human-class lunar lander capability demonstration missions, status of other human systems, other possible mission enhancements (e.g., retro-braking stage, launch vehicle availability) make decision on date and method of human lunar surface return and the mission objectives.

Post 2024 Decisions:

• Based on the cost of lunar surface access, viability of higher-power systems and ISRU, as revealed by exploration and science missions and technology investments, and on private-sector and international demand for lunar surface access, determine the nature of a sustainable American human presence on the lunar surface and associated infrastructure

development projects.

Mars:

2019:

• Decision on Mars robotic roundtrip mission (Mars Sample Return) implementation and architecture and target launch date.

• Decision on Mars-forward technology R&D investment portfolio in Exploration Research and Technology (ER&T).

• Prioritize and guide investments and partnerships in “long-pole” technology areas and resource characterization needed for the exploration of Mars and other deep space destinations (ongoing).

• Develop standards for human long-duration deep space transportation vehicles (ongoing).

2021:

• Based on results of Mars 2020, the Mars Oxygen ISRU Experiment (MOXIE) payload, and helicopter performance, modify Mars-forward technology R&D investment portfolio in ER&T.

2024:

• Based on results of investment in Mars-forward technology R&D investment portfolio, Gateway development and operations, launch vehicle and crew vehicle development and operations, decide on architecture of human Mars orbital mission and begin associated systems development.

Post-2024 Decisions:

• Based on results of robotic roundtrip mission, cislunar operations, and progress of Marsforward technology R&D investment portfolio, determine set of technology investments and timeline required to achieve human landing on the surface of Mars.