At 1:24:59 pm US Central Standard Time on December 19, 1972, the Apollo 17 command module splashed down in the Pacific Ocean, about 350 nautical miles southeast of Samoa, ending the last American manned mission to the Moon.
During his career, Apollo 17 commander Eugene A. Cernan logged 566 hours and 15 minutes in space, of which more than 73 hours were spent on the surface of the Moon. Cernan was the second American to walk in space and the last person to leave his footprints on the surface of the Moon.
The completion of Apollo 17’s journey marked not just the end of a mission, but the end of an era. Between 1969 and 1972, 12 astronauts walked on the Moon in six separate landings.
Half a century later, NASA is returning to the Moon, with its Artemis program. For the Artemis II mission, which was launched on April 1, 2026, four astronauts will fly over the far side of the Moon inside a manned capsule – Orion.
More than 50 years is a long time, and it’s natural to ask: if Americans were routinely able to reach the Moon in the early 1970s, why did it take them so long to try to get back?
The answer is not simple. It has little to do with technology and much more to do with how politics, money and global support work. The starting point is the Apollo program itself: its exploration model was not built to last, and was clearly not sustainable.
Image taken by the Artemis 2 crew on Monday (April 6, 2026) shows the Moon fully illuminated, with the visible side (the hemisphere we see from Earth) being on the right. It is identifiable by the dark spots that cover its surface.
On May 25, 1961, before a joint session of the American Congress, President John F. Kennedy committed the United States to the goal of landing a man on the Moon and returning him safely to Earth before the end of that decade.
After Kennedy’s assassination in 1963, President Lyndon B. Johnson ensured that this Moon landing goal was met. But the rising costs of the Vietnam War and domestic reforms reduced interest in new space investments.
In fact, NASA’s budget peaked in 1966 and began to decline even before the success of the Apollo program, hurting prospects for sustainable exploration. Additional funding was rejected, planned missions were cancelled, and the Apollo program came to an end in 1972 – not because it had failed, but because it had fulfilled its mission.
Sustainable exploration (both in space and on Earth) requires stable political commitment, predictable funding, and a clear long-term objective. After Apollo, the US had difficulty maintaining these three aspects simultaneously.
Policymakers began to question what direction NASA should take next. In 1972, then-President Richard Nixon instructed the space agency to begin construction of the space shuttle. This would lead NASA to shift its focus from deep space exploration to operations in low Earth orbit.
Apollo 17 was the last manned mission to land on the Moon
Billed as a reusable “space truck,” the space shuttle was intended to make access to Earth orbit routine and relatively inexpensive. But it would end up proving to be a vehicle of incredible complexity, marked by technical failures and human tragedies – the Challenger and Columbia accidents, in which 14 astronauts lost their lives.
Eight years after the start of the space shuttle program, some in the aerospace community believed it was time for the U.S. to set its sights on the Moon again — and the tantalizing prospect of a Mars landing. On July 20, 1989, the 20th anniversary of the first Apollo 11 lunar landing, President George H. W. Bush announced the Space Exploration Initiative (SEI).
The plan envisioned a long-term commitment to build Space Station Freedom, return astronauts to the Moon “to stay,” and ultimately send humans to the Red Planet.
But SEI’s high estimated costs, running into hundreds of billions of dollars, led to its failure. Weak support in Congress, along with other factors, led to its cancellation under President Bill Clinton.
During the 1990s, the International Space Station (ISS) project established low Earth orbit as a priority for human exploration. The space shuttle was the means used by the US to build the station and transport crews to and from the orbiting outpost.
The ISS has become a symbol of international scientific cooperation and technical prowess. Experiments carried out at the station have generated valuable insights into everything from medical research to materials science. But they also consumed resources that might otherwise have supported deep space exploration.
Columbia space shuttle accident happened 15 days after the aircraft’s launch
The Columbia disaster in 2003 – in which the space shuttle disintegrated over Texas, causing the deaths of the entire crew – led to new reflection on the direction of space exploration in the United States. As a result, President George W. Bush announced the Vision for Space Exploration.
The objective of this proposal, which would give rise to what became known as the Constellation Program, was to rebuild NASA’s ability to reach the Moon, with Mars as a long-term goal. But independent reviews warned the costs and timelines were unrealistic. The US Congress never gave full financial support to Constellation, leading to its cancellation in 2010, during the Presidency of Barack Obama.
This repeated cycle of canceled space projects exposes some inherent limitations to the lunar exploration financing system. A sustainable lunar program needs strong multi-sectoral commitment and mechanisms to secure funding for several decades.
But programs of such magnitude must compete annually with spending on defense, health and social assistance. Electoral turnover and changes in the leadership of commissions in the US further weaken the prospect of continuity.
Lunar exploration has also suffered from an unresolved strategic question: Why go back at all? The purpose of the Apollo program was largely geopolitical, and after the Cold War no equally compelling justification really emerged.
The scientific returns from manned space missions are limited compared to robotic exploration. Commercial prospects remain uncertain, and prestige alone rarely sustains or guarantees large budgets.
Perhaps a better question is: why does Artemis seem to have escaped this pattern? Well, NASA argues that sending astronauts back to the lunar surface — and, in particular, establishing a sustained presence there — will help researchers learn “how to live and work on another world as we prepare for crewed missions to Mars.” This is true, to a certain extent.
In the image, the Earth seen from the far side of the Moon
NASA also emphasizes that Artemis will be built through commercial partnerships and international cooperation, creating the first long-term human presence on the Moon.
The program appears to sit at a carefully crafted intersection between U.S. government leadership, commercial launch capabilities, and a broad coalition of international partners brought together under the Artemis Accords. The agreements are a set of common principles regarding the use of the Moon and other targets in outer space, agreed between the US and other countries.
The main difference from previous promises to return to the Moon is that this, at least in theory, spreads the risk and broadens the base of political support. In practice, however, Artemis remains expensive and is exposed to changes in budgets and priorities.
There is also a cultural dimension to this issue. The Apollo program created a powerful—if fragile—myth of rapid and heroic technological advancement. Artemis is building its broad technological base in democratic societies and contexts where investments and commitments tend to evolve slowly, shaped by negotiations, agreements and competing interests.
If Artemis succeeds, it will be because all political, economic, social and scientific incentives have finally aligned in a lasting way. But until this alignment is proven, the 50-year gap between Apollo and Artemis is less an engineering puzzle than a reminder of how difficult sustained space exploration is for modern democracies.
This text was originally published by The Conversation, on April 2, 2026. It was written by . The content is free for republication, citing the source.
