On March 26, 2019,

How does NASA plan to land humans on the Moon by 2024?

“It is the stated policy of this administration and the United States of America to return American astronauts to the Moon within the next five years… To be clear: the first woman and the next man on the Moon will both be American astronauts, launched by American rockets from American soil.” Vice President Mike Pence

at a meeting of the National Space Council in Huntsville, Alabama, Vice President Mike Pence announced that the United States plans to send the first woman and the next man to the lunar surface by the end of 2024. In the weeks following this announcement, there were few details about the new lunar program, but on May 13, 2019, the Trump Administration released the National Aeronautics and Space Administration’s (NASA) revised fiscal year (FY) 2020 budget and the mission to return humans to the Moon by 2024 was dubbed “the Artemis program.”

On April 30, 2019, Bill Gerstenmaier—who at the time was NASA’s Associate Administrator of the Human Exploration and Operations Mission Directorate—explained that the agency’s approach to land the first woman and the next man on the Moon by 2024 requires three launches of the new Space Launch System (SLS). At 322 feet tall, the SLS is capable of delivering 26 metric tons of cargo or NASA’s astronauts to cislunar space.

On the first mission, called “Artemis I,” the SLS will launch an uncrewed Orion spacecraft around the Moon by the end of 2021. Artemis I will be followed by “Artemis II,” a crewed test flight of the Orion spacecraft around the Moon that will launch as early as 2022. Lastly, “Artemis III” will deliver humans to a minimalist version of the Lunar Gateway, an optionally-crewed habitat in orbit around the Moon, in order to send the first woman and the next man to the lunar surface by the end of 2024.

This minimalist Lunar Gateway will include a power and propulsion element and a habitation unit. These two elements of the Lunar Gateway will be launched by commercial rockets and serve as a “parking space” for a lunar lander. The lunar lander will be capable of delivering two astronauts from the Lunar Gateway to the lunar surface and back.

How does this plan differ from the original plan to send humans to the Moon by 2028?

Prior to the announcement of the Artemis program, NASA’s plans to send astronauts to the lunar surface were outlined in a September 2018 report, entitled the “National Space Exploration Campaign Report.” This report stated that NASA was building a plan for Americans to orbit the Moon in 2023, to send astronauts to the Lunar Gateway by 2024, and land astronauts on the lunar surface no later than the late 2020s.

NASA promoted a 2028 lunar landing date as late as March 11, 2019, when the Trump Administration released its initial FY 2020 budget request. However, the Vice President’s announcement on March 26, 2019, required NASA to revise its plans to accommodate a crewed lunar landing by 2024.

One such revision was a significant reduction in the near-term scope of the Lunar Gateway. The Lunar Gateway envisioned for the original 2028 mission deadline included seven distinct modules, as well as a robotic arm and sample return vehicle. While the non-essential elements of the Lunar Gateway are no longer planned for deployment before 2024, NASA still plans on developing and launching these platforms in the years following 2024.

In addition to limitations on the scope of the Lunar Gateway, the lunar lander for the Artemis program is being designed to carry two, rather than four, crewmembers. The astronauts who travel to the lunar surface are also likely to spend less time than the one week missions planned for the original 2028 deadline. In order to achieve the 2024 deadline, the Artemis program will also require more commercial engagement at an earlier date than initially planned.

What role will international partnerships play in the Artemis program?

Prior to the Vice President’s Moon 2024 announcement, NASA had extensive plans for international cooperation in the construction of the Lunar Gateway, releasing a detailed graphic (Figure 1) just two weeks before the Vice President’s announcement.

Since Vice President Pence’s announcement, Administrator Bridenstine has acknowledged that other than existing agreements, like the European Service Module for the Orion spacecraft, there will be limited opportunities for international cooperation prior to the 2024 lunar landing.

After the 2024 lunar landing, Administrator Bridenstine hopes to involve more international partners in the expansion of the Lunar Gateway. As of July 2019, Canada has agreed to supply the robotic arm for the Lunar Gateway, while Japan has broadly agreed to cooperate with the United States on lunar exploration. Additionally, on June 19, 2019 the French space agency signed an accord with NASA that will allow France to play a role in the Artemis program. Further discussions on involvement with the Artemis program will take place in November 2019 in Seville, Spain, with other European national space agencies and the European Space Agency.

Why is this mission called the Artemis program?

NASA has a long-standing tradition of naming human spaceflight programs after figures in Greco-Roman mythology. For example, Project Mercury, which preceded the Apollo program, and the Saturn V rocket, which lifted Apollo astronauts off of the Earth’s surface, are both named after Greco-Roman gods.

Artemis is a fitting moniker for a program that aims to take the first woman to the surface of the Moon, as Artemis is the goddess of the Moon and Apollo’s twin sister.

How much will the Artemis program cost?

In an interview released by CNN on June 13, 2019, NASA Administrator Jim Bridenstine estimated that the total cost of the Artemis program will be an additional $20 to $30 billion over the next five years.

Bridenstine previously noted that NASA’s FY 2020 budget amendment is intended as a “down payment” for the Artemis program. Because the amendment only adds $1.6 billion of funds to NASA’s current budget request for FY 2020—bringing the agency’s topline to about $21 billion—the Artemis program is likely to cost an additional $4.6 to $7.1 billion per year on top of NASA’s planned budgets for fiscal years 2021 through 2024.

Table 1: Total NASA Planned Appropriations for FY 2020-2024 (Billions of USD)

FY 2020 FY 2021 FY 2022 FY 2023 FY 2024 Estimates prior to Artemis announcement $21.0 $21.2 $21.4 $21.7 $21.9 Updated estimates to account for Artemis program $22.6 $25.8 – $28.3 $26.0 – $28.5 $26.2 – $28.7 $26.5 – $29.0

However, if Congress chooses to cut funding for other NASA programs in order to fund the Artemis program, the additional appropriations required to fund the program will be reduced. Administrator Bridenstine has said on several occasions that he will do his best to ensure that the Artemis program is funded without “cannibalizing” other NASA programs. Yet, on May 31, 2019, at a meeting of NASA’s Advisory Council, Bill Gerstenmaier stated that he did not believe that NASA would be able to get the entire budget as additional appropriations and that the leaders of NASA have already met to discuss which programs can be cut or delayed.

What will NASA’s FY 2020 budget amendment pay for?

Of the nearly $1.6 billion in additional funds that the amendment requests, $1 billion is allocated for the development of a human lunar lander system, $651 million is allocated to accelerate the development of SLS and Orion, $132 million is allocated to certain exploration technologies—such as solar electric propulsion and a demonstration of space resource utilization capabilities—and $90 million is requested to enable increased robotic exploration of the Moon’s polar regions. Lastly, the budget amendment cites about $321 million in reductions from limiting the scope of the Lunar Gateway to only the elements required for a crewed lunar landing in 2024.

Table 2: NASA’s FY 2020 Budget Amendment Breakdown

Appropriations Millions of USD Development of Human Lunar Lander $1,000 Acceleration of SLS and Orion $651 Development of Exploration Technologies $132 Additional Science $90 Descoping the Lunar Gateway – $321 Total ~ $1,600

Where will NASA receive these extra funds from?

The Trump administration’s budget amendment submitted to Congress on May 13, 2019, would cut $1.9 billion from the Pell Grant program to fund the Artemis program’s nearly $1.6 billion request, as well as several smaller projects.

The Artemis program has received a cool reception from House Democrats. On May 22, 2019, the House Appropriations Committee approved a spending bill that largely ignored the President’s budget amendment. Administrator Bridenstine was quick to note that NASA’s budget amendment was released only a few days before the House Appropriations Committee voted on the bill. Because the committee did not have enough time to review the amendment and add it to the bill, Bridenstine does not see the budget amendment’s exclusion as a rejection of the proposal.

NASA is likely to have better luck in the Senate, as Senator Jerry Moran (R-KS), Chair of the Senate Appropriations Subcommittee for Commerce, Justice, and Science tweeted that he will work with the administration to “make certain NASA has the resources to land the first woman on the Moon and build lasting infrastructure to support missions to Mars and beyond.”

At this point, it is unclear how much money, if any, Congress will allocate to the Artemis program in FY 2020, but Administrator Bridenstine remains optimistic, reminding everyone that “we’re still in the top of the first inning” when it comes to the Artemis program.