As Apollo 17 commander Gene Cernan took his final steps before quitting the lunar surface, he delivered a poignant farewell: “We leave as we came, and, God willing, as we shall return, with peace and hope for all mankind.”
The date was 14 December 1972. Cernan knew his footprints would mark the lunar soil as the last for some time. The planned follow-up missions – Apollos 18, 19 and 20 – had already been scrapped. Yet he could hardly have imagined that, more than 50 years later, his words would still stand as the last human utterance on the moon.
NASA now prepares to launch Artemis II as soon as 1 April, following recent testing delays. The mission will perform a lunar fly-by, not a landing. Still, it represents humanity’s first voyage near the moon since Apollo 17, reports CNN.
So why the half-century hiatus?
“The short answer to that question is political will,” said Teasel Muir-Harmony, a historian of science and technology and the curator of the Apollo Collection at the Smithsonian National Air and Space Museum in Washington, DC.
“It takes a whole lot of political will to send humans to the moon. These are extremely complex, really costly, major national investments. It has to be a priority over a sustained period of time.”
Muir-Harmony added that, after budget cuts ended the Apollo programme, several federal initiatives tried to return humans to the moon.
“But what’s happened is that as presidential administrations changed, space priorities for these large-scale programs also changed. And so we just haven’t seen the sustained political will to follow through with a program that will take many years, significant funding and lots of resources in general.”
Les Johnson, a former NASA chief technologist who worked at the agency for over three decades, agreed. Rapidly shifting political objectives have been key. “Every four to eight years, NASA has its human spaceflight goals and objectives completely, totally, radically altered,” he said.
“When I joined NASA in 1990, we were directed to go back to the moon by then President George HW Bush. But when President Clinton took office in 1993, he canceled that. He said, we’re going to make the space station happen – don’t do anything associated with going back to the moon,” Johnson recalled.
“We did that for eight years, and then in 2001 we got George W. Bush, and he said, cancel all this other stuff and let’s focus on going back to the moon. So we did, and a project called Constellation was born, which survived the two terms of the second Bush presidency.”
The cycle continued. Barack Obama moved NASA’s priorities toward asteroid sampling. President Donald Trump shifted back to lunar goals. Then, after 2020, Joe Biden broke the pattern.
“He was the first president in my career at NASA who did not change everything,” Johnson said of Biden. “He said, I really didn’t like a lot of what Trump did, but I think going back to the moon is a good idea. Let’s just keep going.”
Now, in Trump’s second term, his administration has recently doubled down on returning astronauts to the lunar surface – intent on outpacing China in the new space race.
Political hurdles aside, moon missions pose staggering technical challenges. Earth’s natural satellite lies roughly a quarter of a million miles (over 400,000 kilometres) away. More than half of all lunar landing attempts have ended in failure.
The Artemis programme using a rocket and spacecraft that took two decades and more than $50 billion to complete – represents NASA’s latest and most promising attempt to make such feats achievable.
Many similarities between Apollo and Artemis are undeniable, including a near match in mission profile between Apollo 8 and Artemis II. But recreating the Apollo programme today would be neither practical nor logical.
The supply chains and skilled machinists who built the hardware for those mid-20th century moon missions have long since vanished.
“People ask what was wrong with Apollo,” Wayne Hale, a former NASA space shuttle program manager, previously said during a Human Exploration and Operations Committee meeting. “The thing that was wrong with Apollo was it ended.”
One often-cited piece of Apollo lore holds that the programme’s spacecraft and rockets ran on computers less powerful than a modern smartphone. NASA has since put many computing advancements to use, especially in robotic exploration of other worlds.
Yet spaceflight – and human spaceflight in particular – remains far too complex, dangerous and expensive for computing advances to translate directly into easier, cheaper moon missions. Technology on Earth benefits from testing by millions of users and decades of mass production. Deep-space missions demand multibillion-dollar contracts and years of continuous work toward a single goal – a rare commodity in the post-Apollo era of stop-start presidential exploration programmes.
As Casey Dreier, the chief of space policy at The Planetary Society, a nonprofit exploration advocacy group, noted: The Artemis programme is the most successful moon programme the United States has had in decades – “because it still exists.”
At the technical level, the differences between Apollo and Artemis spacecraft are vast. Orion’s flight computers run 20,000 times faster and possess 128,000 times more memory than the lone machine that guided Apollo.
The Orion capsule offers its crew – increased from three to four – more room for exercise and entertainment. And a far superior toilet. “With the Apollo program, the astronauts had a waste collection device which was like a plastic bag with a rim, and they would stick it upon themselves. Not the most pleasant experience,” Muir-Harmony said.
Aboard Orion, which has about a third more habitable space than Apollo, the crew will enjoy a real bathroom. “It’s a little room tucked into the spacecraft that they can go inside,” Muir-Harmony said. “It looks like a little closet or a little phone booth. It’s small, but there’s some privacy, which is pretty essential when you have a crew that’s both men and women.”
During the Apollo era, she added, the bathroom issue fed into the debate over whether women should become astronauts. “The Soviet program had a woman fly in space 20 years before the United States did. But some people said that designing bathroom technology for women in space was going to be too complicated,” Muir-Harmony said.
“You can debate that, but it is important to think through privacy when you have a crew of both men and women, and so they were able to achieve that with the design of the Orion spacecraft.”
In-space bathrooms have come a long way since Apollo. The International Space Station, for instance, has a comparatively spacious stall for washing and using the toilet. The SpaceX Crew Dragon capsule – which has ferried astronauts to and from the orbiting laboratory since 2020 – includes a small private area with a vacuum toilet.
