CNN —
As he took his final steps before leaving the Moon, Apollo 17 commander Gene Cernan delivered poignant farewell words: “We leave as we came and, God willing, as we shall return, with peace and hope for all mankind.”
It was December 14, 1972, and Cernan knew his footprints would be the last on the lunar surface for some time, as planned Apollo missions 18, 19, and 20 had long been canceled. But he likely didn’t anticipate that, more than 50 years later, his words would remain the last spoken by a human on the Moon.
The upcoming Artemis II mission, currently scheduled for launch in March following recent testing delays, will fly around the Moon rather than land. Nevertheless, the mission will mark humanity’s first journey to the vicinity of the Moon since Apollo 17.
So why has a return to the lunar surface taken so long?
“The short answer to that question has to do with political will,” said Teasel Muir-Harmony, a historian of science and technology and curator of the Apollo Collection at the Smithsonian National Air and Space Museum in Washington, D.C. “It takes a lot of political will to send humans to the Moon. It’s incredibly complex, very expensive, and nationally important investments. It has to be a long-term priority.”
Over the years since the Apollo program ended due to budget cuts, there have been several other federal initiatives to send humans back to the Moon, Muir-Harmony added. “But what has happened is that as presidential administrations have changed, the space priorities of these large-scale programs have also changed. So, we simply haven’t seen the sustained political will to carry out a program that requires many years, significant funding, and a lot of resources overall.”
Les Johnson, a former NASA chief technologist who worked at the agency for over three decades, agreed that the rapidly shifting political goals have been a key factor. “Every four to eight years, NASA sees its goals and objectives for crewed spaceflight totally and radically altered,” he stated.
“When I joined NASA in 1990, President George H.W. Bush directed us to return to the Moon. But when President Clinton took office in 1993, he canceled it. He said, ‘Let’s make the space station a reality; don’t do anything related to going back to the Moon,’” Johnson explained. “We did that for eight years, and then, in 2001, George W. Bush came along, who told us, ‘Cancel everything else and let’s focus on going back to the Moon.’ That’s what we did, and a project called Constellation was born, which survived both terms of the second Bush presidency.”
The cycle continued with Barack Obama, who made asteroid sampling a priority for NASA, and with President Donald Trump, who took office and refocused on lunar objectives. After 2020, Joe Biden broke the pattern.
“He was the first president in my career at NASA who didn’t change everything,” Johnson said of Biden. “He said, ‘I didn’t much care for what Trump did, but I think going back to the Moon is a good idea. Let’s move forward.’” Now, in Trump’s second term, his administration has doubled down on its campaign to return astronauts to the lunar surface, with the intention of outpacing China in the new space race.
However, setting aside the political hurdles, lunar missions also present considerable technical challenges. Earth’s natural satellite is approximately a quarter of a million miles (over 400,000 kilometers) away, and more than half of all lunar landing attempts have failed. The Artemis program, which utilizes a rocket and spacecraft that have taken two decades and over $50 billion to complete, is the most recent and promising attempt by NASA to make such feats a reality.
Many similarities between Apollo and Artemis are undeniable, including a near-total match in mission profile between Apollo 8 and Artemis II, but recreating the Apollo program today wouldn’t have been a practical or logical option.
Gone are the supply chains and skilled machinists who built the hardware for those mid-20th century lunar missions.
“People ask what was wrong with Apollo,” Wayne Hale, a former NASA Space Shuttle Program Manager, said during a meeting of the Human Exploration and Operations Committee. “What was wrong with Apollo is that it ended.”
In the years since the Apollo program concluded due to budget cuts, there have been several other federal initiatives to send humans back to the Moon, Muir-Harmony added. “But what has happened is that as presidential administrations have changed, the space priorities of these large-scale programs have also changed. We simply haven’t seen the sustained political will to carry out a program that requires many years, significant funding, and a lot of resources overall.”
James W. Head, a professor of Earth, environmental and planetary sciences research at Brown University who worked on the Apollo program, noted that the technology available today is vastly different. The Artemis spacecraft, for example, boasts computing power 20,000 times faster and 128,000 times more memory than the single machine that guided Apollo.
The Orion capsule offers the crew (increased from three to four) more space and opportunities for exercise, and entertainment. And a much better bathroom. “With the Apollo program, astronauts had a waste collection device similar to a plastic bag with a flange, which they stuck on top. It wasn’t the most pleasant experience,” Muir-Harmony said.
Onboard Orion, which has roughly a third more habitable space than Apollo, the crew will enjoy the luxury of an actual toilet. “It’s a small room tucked away inside the spacecraft that they can access,” Muir-Harmony said. “It looks like a small closet or a small phone booth. It’s small, but it offers some privacy, which is essential when you have a crew composed of both men and women.”
During the Apollo era, she added, the issue of bathrooms was part of the debate over whether women should be astronauts. “The Soviet program had a woman flying in space 20 years before the United States. But some said that designing bathroom technology for women in space would be too complicated,” Muir-Harmony said. “You can debate that, but it’s important to consider privacy when you have a crew composed of both men and women, and they achieved that with the design of the Orion spacecraft.”
Space toilets have come a long way since the Apollo program. The International Space Station, for example, features a comparatively spacious stall for washing and using the toilet. And SpaceX’s Crew Dragon capsule, which has been transporting astronauts to and from the orbital laboratory since 2020, includes a small private area with a vacuum toilet.
The objectives of both programs are also markedly different. The Apollo program already completed the unique “flags and footprints” missions, Hale affirmed.
Now, NASA aims to create the infrastructure to enable astronauts to live and perform at a lunar base, creating a sustainable and permanent human presence on the Moon. “That means the landers being developed are designed to stay there for more than a day. They’re meant to be part of a larger architecture or system that will eventually have habitats on the Moon,” Johnson said, adding that even as the next Artemis II flight mirrors Apollo 8, the programs will diverge drastically after that.
The rise of the commercial space industry has helped drive this decisive push to renew lunar plans, according to Brian Odom, NASA’s chief historian.
“NASA is now a customer of a private industry where we have SpaceX, Boeing, and Blue Origin. That’s an enabling factor that has helped us,” Odom said.
SpaceX is one of the most important partners, and its CEO, Elon Musk, recently announced a dramatic shift in focus: prioritizing building a “self-sustaining city on the Moon” over sending humans to Mars.
However, Odom added, returning to the Moon has always depended on several pieces falling into place. “Space is very complex and requires the convergence of many different factors. Commercial commitments, international commitments, and now government, working together, are what have really allowed us to obtain to this point,” he said.
“It’s been a long road, but returning has always been a strategy, and it’s emerged at a couple of different moments. Now we have the infrastructure, we have partners, and it’s becoming possible.”
Crucially, a prolonged human presence on the lunar surface will also benefit from the experience gained through post-Apollo programs, such as the International Space Station, where humans have had a permanent presence for over 25 years.
“Returning to the Moon will require prolonged stays on the lunar surface and, understanding the effects of space habitability on the human body,” said James W. Head, a research professor of Earth, environmental and planetary sciences at Brown University, who worked on the Apollo program.
“And robotic missions conducted in the meantime, such as NASA’s Lunar Reconnaissance Orbiter, have provided insights into where to go and identify the resources needed to support human presence, indicating the possibility of water resources trapped at the lunar poles.”
And if world leaders need additional motivation, Head added, they should consider the words of Apollo 16 commander John Young, who, before retiring in 2004, was asked what the point was of spending money to go to the Moon. “The geological history of Earth is quite clear: it says, frankly, that single-planet species do not endure,” Young stated.
The Apollo program had to contend with the deadline imposed by President John F. Kennedy, who in 1961 declared to Congress his goal of landing a man on the Moon before the decade was out. He wanted to beat the Soviet Union, which had already put a satellite and a man into orbit before the United States.
