Last time America went to the Moon, in 1972, half a million people turned up to watch. Things didn’t exactly go smoothly. Moments before lift-off, as automatic systems prepared to ignite the mighty engines of the Saturn V rocket, an error flashed up. The countdown was halted, just thirty seconds left on the clock, and controllers scrambled to intervene.
Two hours later, shortly after midnight on the morning of December 7, the waiting crowds got what they came for. The Saturn V roared to life; its flame lighting up the Kennedy Space Centre as bright as day. As it soared upwards, the flame burned a pinkish red visible as far away as Miami and Alabama.
And that, apart from one more Saturn V launch to put Skylab in orbit, was that. After Apollo 17 the Moon Program drew to a close. The men aboard - Gene Cernan and Harrison Schmitt - became the last to walk on the lunar surface. The two remaining Saturn Vs were put quietly aside, lingering on today as museum pieces.
No human being has since ventured more than a few hundred miles from Earth. The brief window of possibility opened by the project, the visions of reaching out into space, of visiting Mars and Venus, of sending people to live permanently beyond our planet, proved nothing more than a brief, if heady, illusion.
Might things finally be about to change? For the first time since the 1970s, America has a fully loaded Moon rocket ready for launch. Sometime in the next week or so that rocket will lift off; soar gracefully into the heavens and send an unmanned capsule towards the Moon.
NASA, too, has a plan: one that calls for a decade or more of exploration; one that speaks of building a permanent base around the Moon. If it succeeds, the Artemis Program - as this plan is labelled - will see a fundamental shift in the way we think about the Moon.
It will no longer be a dead world; a place we visited, briefly, and then abandoned. If Artemis succeeds, the Moon will instead become a place more akin to Antarctica: a cold and unforgiving place, yet one regularly touched by the hands of men and women.
Still, that “if” is still a big one. If humans are to return to the Moon and stay there for any amount of time, a lot of work remains to be done. Landers need to be built, orbiting stations designed, spacesuits readied and astronauts trained. And – perhaps most important of all – a new Moon rocket must be tested.
The Rocket
This new rocket is called the “Space Launch System”. That - it has to be said - is an awful, uninspired name. It lacks the romance of the Saturn V, or even of the Ares I, its immediate predecessor. It is, unfortunately, the kind of name that emerges from the heart of bureaucracy, the selection, no doubt, of some dull committee.
Still, the name may be fitting. The Space Launch System, or SLS, is a creature born in bureaucracy. It emerged from the wreckage of the Constellation Program, an earlier effort by NASA to find a way forward for human spaceflight after the retirement of the Space Shuttle.
Constellation had three key components: a rocket, Ares; a moon lander, Altair; and a deep space capsule, Orion. Of the three, only Orion has survived to the present day - and having been tested twice, now sits atop of the SLS.
Altair never got beyond the drawing board, and was consigned to the trash bin when Constellation was cancelled. But the Ares rocket - which did, indeed, once fly - has lived on through the SLS. Two versions of this rocket were originally envisioned.
The first, the Ares I, was intended to carry astronauts. The other, the Ares V, was imagined as a powerful rocket strong enough to carry cargo and supplies into deep space. Both were designed to continue the legacy of the Space Shuttle, using, in many cases, components designed for that earlier spacecraft.
When Constellation was cancelled, in 2011, these two varieties were combined into a single rocket: the SLS. It, like the Ares V, is a big rocket, designed to carry hardware far beyond Earth. But, like the Ares I, it can also carry astronauts, and as such will form the heart of NASA’s plan to return humans to the Moon.
The SLS, too, reuses Space Shuttle technology. When the countdown hits zero and the rocket ignites, it will do so with engines that once flew on the Shuttle. Four RS-25 engines will provide this initial thrust, and each has already flown on several shuttle missions. Several other components, including the side boosters, include parts from other Shuttle flights.
Yet whatever lofty goals might have inspired it, the SLS has spent its life mired in politics and paperwork. Its development has been hugely expensive – totalling more than twenty billion dollars. It is running years behind schedule – a first launch was once planned for 2016 – and far over the original budget.
It is likely, too, to be incredibly expensive to fly. Each launch is expected to cost more than four billion dollars – an enormous sum for a rocket that will, quite literally, be dumped into the ocean after each flight. And those launches will be infrequent: because of the time needed to construct each rocket, no more than one SLS launch can be expected per year.
Critics, of which there are many, argue that this money would be better spent elsewhere. Yet, for better or worse, NASA has invested an enormous sum into the SLS. Whatever its faults, the rocket is ready for lift-off: and, perhaps, ready to usher in a new era of space exploration.
The Mission
Over the past few months engineers have completed a series of exhaustive and final tests of the rocket. They have verified almost every step of the launch, rehearsing everything until the final few seconds before lift-off. They are, in other words, as sure as can be possible – without actually lighting the fuse – that the rocket is ready to fly.
NASA has selected three possible dates for the lift-off. The earliest is August 29th; the others are on September 2nd and September 5th. Which is used will depend on weather conditions around the launch pad. Conditions must be clear and stable for the launch to go off without a hitch.
Mounted on top of the SLS will be an Orion capsule: unmanned, this time, save for a mannequin and two toys: Snoopy, from NASA, and Shaun the Sheep, from ESA. Shortly after lift-off, the SLS’s upper stage will send this capsule towards the Moon, a journey that should take no more than five days.
After arriving, Orion is expected to spend several days orbiting the Moon. Its trajectory will bring it both close to the surface - just sixty miles high - and far, to a maximum of forty thousand miles distant. Then, once controllers have gathered enough data on its performance, Orion will head for home.
Orion has already, in a 2014 test, demonstrated that it can re-enter and splashdown safely. But this time controllers will push its limits, sending it on a course that will impact the atmosphere at speeds of twenty-five thousand miles per hour.
As it falls back to Earth NASA expect Orion to reach temperatures of thousands of degrees: proving, hopefully, that the capsule is strong and safe enough to carry astronauts. And then, after a voyage of more than six weeks and over a million miles, the capsule will splash down in the Pacific Ocean, somewhere off the coast of California.
Also onboard are a set of small satellites. These include missions to spot and map ice on the Moon, to visit a nearby asteroid, and even a small lander that should touchdown on the lunar surface. That’s if they work at all - the satellites have been stored inside the rocket for more than a year, and nobody knows if their batteries are still charged.
The Artemis Program
This flight around the Moon is labelled Artemis I, the first mission of NASA’s Artemis program. It is intended, in some ways, as a replica of the planned Apollo 6: a mission that would have seen an uncrewed lunar module sent towards the Moon by the Saturn V. That mission, too, sought to prove a new and gigantic rocket, and to demonstrate that it was capable of reaching the Moon.
Yet the analogy is not always a positive one: Apollo 6 failed to get as far as hoped. Problems during the launch – thanks to unforeseen vibrations – shut the rocket’s engines down early, leaving the final stages in a lower than expected orbit. Unable to fix the problem, NASA instead switched focus, attempting to simulate re-entry from the Moon, instead of the voyage there.
Despite all that, Apollo 8 – the next launch of the Saturn V – carried a crew of astronauts, and sent them safely into orbit around the Moon. They did not land – that honour was saved for the crew of Apollo 11 – but they did become the first humans to directly view the far side of the Moon. Artemis will replicate that mission too – Artemis II, scheduled to fly in 2024, will ferry a set of six astronauts to lunar orbit.
Then, probably around 2026, NASA will attempt to stage the first Moon landing since 1972. Artemis III will set two humans – one man and the first woman – on the lunar surface, where they will spend around a week conducting experiments and exploring the surface. That, of course, promises to be a momentous occasion, one watched by billions around the world.
Beyond the road becomes vaguer. NASA has plans to construct a space station – known as the Lunar Gateway – around the Moon. It will, they hope, provide a temporary home for visiting astronauts and act as a base of operations for forays to the surface.
The Gateway would allow astronauts to stay for a month or so, and to make repeated trips to the Moon’s surface. If it is built, it would solidify the future of lunar exploration, paving the way for decades of visits to the Moon. That, hopefully, means NASA will avoid repeating Apollo 17, and avoid abandoning the Moon for another half century.
The Future
All this, of course, depends on far more than the SLS. If it launches successfully next week, NASA will have a proven Moon rocket. But they still do not have a lander, nor space suits for the crew to wear on the surface. Both are under development, but neither may be ready in time for a landing in 2026. Indeed, NASA has already delayed the landing several times – plans originally called for astronauts to walk on the surface by 2024.
The agency is likely to delay things again, but a landing before the end of this decade does not look unlikely. Indeed, given the rising possibility of a Chinese landing in the 2030s, NASA may find itself under increasing political pressure to get there first. A new space race – if America cannot land in the next few years – is not out of the question.
Might America also follow through with plans to stick around on the Moon? It’s worth remembering that the Apollo Program, too, was ambitious. It originally called for many more missions, and foresaw a larger effort to explore and settle on the Moon. After the excitement of the landing, and the cooling of the race with the Soviets, those plans were cast aside.
Indeed, though NASA hint at plans for repeated visits to the Moon, the Artemis program is designed in a way which could see it end early. Artemis I, II and III form a standalone set of missions: together they will prove NASA, and America, can still set foot on the Moon. Only once that is done does NASA propose to start building out infrastructure.
It is all too easy to imagine a future where NASA cancels the Artemis program after the third launch: perhaps citing the cost of the SLS, or facing shifting political priorities once more. Not everyone in NASA agrees that the Moon is a good target. Some would prefer to focus our attentions on sending astronauts to more distant places: to nearby asteroids, and eventually to Mars.
In the end, whether NASA stays the course or not probably depends on two external factors: what the Chinese do, and what SpaceX does. China is steadily building out its space program, and already has a space station of its own. The Moon is in its targets, and China’s plans call for a systematic program to put a research base on the Moon by the end of the 2030s. It is hard to imagine America ceding the Moon to China without a fight.
As for SpaceX, their rockets may end up offering a better alternative to the SLS. The company already has the Falcon Heavy, a rocket that could be used to build the Lunar Gateway. A bigger rocket, Starship, could both carry astronauts to the Moon and land them on the surface. NASA already wants to use it as part of Artemis III. It could, too, one day provide a cheap and powerful way to send tonnes of equipment to the Moon, or beyond.
Indeed, even if NASA does stick with the Artemis program, it may morph radically by the end of this decade. In the face of Chinese pressure, America may seek a cheaper and faster path to the Moon. The SLS cannot offer this – but America’s booming private space industry may be able to.