On 21st July 1969, the world was transfixed as Neil Armstrong took his “giant leap for mankind” and stepped on to the surface of the Moon. In the United Kingdom viewers huddled around their new colour television sets, only to discover that the lunar images were in a grainy black and white. In other corners of the Earth these were the first images people had seen on any television. I seem to have been one of the few who missed it. In that pre-internet age I was out of contact, in an old propeller-driven aeroplane, quite unlike the Concorde which had taken its first test flight just a few months before Armstrong’s adventure.
My own memory of that era, when science assumed its most dominant position in the collective imagination and the promise of technology seemed limitless, is of seven months earlier—Christmas Eve, 1968. On that day William Anders, an astronaut on the Apollo 8 mission that circumnavigated the Moon, captured “the most influential environmental photograph ever taken.” His snap revealed a stark barren moonscape, while above the horizon, against the black void of limitless space, hovered the blue jewel of Earth. The image encapsulated our planet’s vulnerability and would in time inspire the beginning of the environmental movement.
Within just a year of Armstrong’s climactic achievement, Robert Frosch, the Nasa administrator, announced there would be no missions beyond those already planned. On 14th December 1972, Gene Cernan became the 12th astronaut to step on this lump of rock, whose surface area is similar to that of Africa and—though nobody could have imagined it at the time—nearly 50 years later he is still the last moonwalker. Apollo provided only the most fleeting disturbance to a silent barren desert: none of the original dozen stayed for more than 75 hours. The Moon never did become a holiday destination, or a stepping stone to what lay beyond.
Flight of faithAt some $500m—in late-1960s dollars—per shot, each Apollo Moon landing cost as much as a year’s research by the National Science Foundation. In the accountancy of scientific advances per dollar invested, there was no contest. On average, each year, five Nobel prizes in physics, chemistry and medicine celebrate research funded at least in part by the foundation. In addition, tens of thousands of other significant advances have been supported by the agency. In contrast, the fundamental science from Apollo has been limited. But then that was never really the point.
Sure, human exploration will always provide opportunities for science. The positioning of mirrors on the lunar surface has enabled precision measurement of the Moon’s range by the reflection of laser beams back to Earth. These measurements over about 400,000kms of space are accurate to within about a centimetre—it turns out that the Moon is gradually receding from the Earth at the same rate that your fingernails grow. This degree of precision has revealed day-to-day modulations in the rotation of the Earth and also slight wobbles as it spins on its axis. They have provided precision tests of the laws of gravity and of the Earth-Moon system, adding to our understanding of our planet’s place in space.
It is at least possible, however, that such instruments could have been set up by robots, bypassing the risks associated with human involvement. And tellingly, whatever scientific justifications for space travel people have come up with since, President John F Kennedy didn’t talk about science in his mission statement in 1961 when the dream of Apollo was first articulated. He didn’t even highlight the geology, where there might have been a case for mining minerals that could—conceivably—benefit the terrestrial economy.
The main spur was not about beauty or truth but bitter ideological rivalry—space was to be a new front in the Cold War. Four years earlier, the USSR had shocked the world with the 1957 launch of its Sputnik probe, the first man-made object put into orbit. Then, in April 1961, the US was hugely embarrassed when Yuri Gagarin, the Soviet cosmonaut, became the first human in space. Within a month a capsule containing the American astronaut Alan Shepherd was launched atop a rocket and successfully parachuted back to Earth. Gagarin, however, had orbited the planet; if anything, Shepherd’s brief up-and-down advertised the relative impotence of the US.
It was three weeks later that the young president—only a few weeks beyond his first 100 days—addressed a Joint Session of Congress and set the goal “before this decade is out, of landing a man on the Moon and returning him safely to Earth.” He believed that the US must catch up and overtake the Soviet Union in the space race and the battle to win minds. There would be rewards for developing new and more powerful propulsion systems; and it was obvious this could also have military value.
So the driver was, unashamedly, the perceived Soviet threat. But the confidence to propose such a flamboyant response to that threat, and to believe it could be done, reflected something else too: a great and of-its-time faith that technology could make anything possible. The Second World War, in which Kennedy had served and which was only half a generation away when he set out his challenge, had seen the American state successfully marshal breathtaking technological initiatives including the Manhattan Project to build the atomic bomb.
Electrification, television, telephony, civilian air travel, even refrigeration: all of these transformative changes to daily life were still within living memory and had seeded the idea that human ingenuity could reorder the future. And not only in America: in Britain, Harold Wilson envisioned “the white heat of the technological revolution.” Developments elsewhere—including Concorde in Europe, and the Soviet success with Gagarin—only encouraged a faith in the possible.
No one would have then believed that in the late-2010s, supersonic passenger travel would—like Moon landings—be a thing of the past. That keen awareness that natural resources were limited—which first entered the popular consciousness with the oil shock of 1973, the year after Apollo was over—was not yet part of the culture.
As it turned out, that very post-war faith in science turned out to be justified in the lunar context. Just eight years after Kennedy’s speech, Apollo launched, carrying Armstrong and Aldrin into history.
The desire to go beyond
The Apollo programme also symbolised something beyond post-war tech-worship—the desire to explore new frontiers. The impulse to plant a US flag on virgin territory was clearly a big part of the impetus, and it was one of the first acts that Armstrong performed on landing. As with the leap of technological faith, there may be an element of this which was “of its time.” European charting of terra incognita and the taming of the American west were much less distant when Kennedy set his challenge than they are today.
But there is something more timeless for humanity in wanting to explore, and that dream—of reaching more deeply into the Universe—did not end with the Apollo mission. Instead, Nasa searched for a substitute and came up with the Space Shuttle, a vehicle presented as a route to low-cost space flight. Soon enough, however, the Challenger disaster reminded a blasé public how risky space travel still was. Nonetheless, into the 1990s and up to the present day, PR-savvy entrepreneurs such as Richard Branson with his Virgin Galactic brand have generated a stream of stories about space tourism being just around the corner.
With even more chutzpah, US presidents including George W Bush and Barack Obama and entrepreneurs such as Elon Musk talk blithely of humans landing on Mars. This might sound like the next “logical step” to take after putting a man on the Moon. But even if we could again drum up the techno-optimism of the 1960s and make a serious go of it, what does the science say about whether this would be possible?
Escaping from our local archipelago to a new planet in the ocean of space would be a singular moment of human endeavour—but it is a highly dubious goal. We have not returned to the Moon in five decades, and a serious project planner would urge us to revisit it first.
Only 10 times further than geostationary satellites, the Moon is not so remote. A round trip there can take less time than a transatlantic voyage on Queen Mary 2. The Apollo return leg took only twice as long as a flight from London to New Zealand. In an emergency, a lunar colony could be reached in about three days.
The challenges in exploring Mars would be qualitatively—and psychologically—very different. Seen from the Moon, the Earth is a glorious sight, up to 16 times larger and brighter than our monthly view of the full Moon. Continents are visible to the naked eye, radio contact is delayed by a mere heartbeat, and a return home can be done in a weekend. From Mars, by contrast, the Earth will be a dot in the vastness of space. On average you would have to wait half an hour for a reply to any radio communication with home. A one-way trip in a spacecraft takes months. Emergencies would have to be dealt with on the spot.
What’s more, whereas there are few prior constraints on the timing of lunar launches, travel between Mars and the Earth requires the pair to be suitably positioned in their orbits. This implies a minimum residency on the red planet of some six months before any return trip could begin. In practice, would humans be able to set up a colony, from scratch, and sustain themselves for half a year? No one knows. Recall, the longest that humans have remained on the lunar surface is 75 hours; we have no knowledge of the reality of surviving in a colony for months on the Moon where in extremis rescue could be made, let alone on Mars where that would be quite impossible.
Then there is the biology to grapple with. The Earth’s surface is a rather safe place in terms of radiation, the planet’s magnetic field providing protection from cosmic rays and also the solar wind: the continuous breeze of electrically-charged particles emitted by our nearest star. Once outside the protection of our atmosphere, however, humans are exposed. The effect of radiation on astronauts in outer space is a serious issue. “Space-weather” such as solar storms and flares could delay a rescue mission, and there is still no practical means of protecting astronauts against space radiation, a danger that could well limit how far space explorers will ever go.
“If human exploration of the solar system becomes a reality, then launching objects from the Moon could become key”
The radiation danger comes not only from the sun’s rays, but also from cosmic rays that originate outside the solar system. Solar flares vary through the solar cycle, and could prove fatal for some of the astronauts—but it is possible to shield against these. By contrast, galactic cosmic rays create dangerous secondary radiation when they hit the spacecraft and are more prevalent the deeper into the solar system one ventures.
Typically, the radiation dose experienced during a round trip to Mars would be about five times what the average citizen on Earth receives in a lifetime. If, as a result of this increased radiation exposure you had, say, a 50 per cent chance of developing terminal cancer within 50 years, you’d have more reason to be put off if you were 20 than if you were 40. So a human visit to Mars is probably feasible within currently accepted radiation dosages for astronauts aged over 40. But then the more middle-aged our Mars-walkers, the more likely there will be questions about health problems, especially problematic when you are months away from the nearest hospital.
A trip to Europa or another of the moons of Jupiter—10 times further away than Mars—would involve astronauts receiving a blast of radiation equivalent to radio-therapy for cancer all over their bodies. Barring some currently unforeseen technology, they would be killed. Humans will probably never be able to travel more than 75 million km on space missions which puts Europa out of range, not to mention Saturn, which lies 1.2 billion km away. Human physiology, then, could render more distant interplanetary travel forever fiction. But it is not a fundamental bar on a potential mission to Mars.
A dream written in the stars
And so the natural challenge remains: Mars is there and can be reached by spacecraft, just as the Moon was there and proved explorable half a century ago. The impulse that says “let’s explore” is the same, but before we return to the Moon—or even more ambitiously, plough on to Mars—there are huge questions that must be meticulously weighed. What are the scientific and economic opportunities, and do they need human presence, or is remote interaction with robots enough? After all, Nasa’s unmanned Mars rovers have not only taken amazing photographs, but also revealed the deep history of the red planet.
But if a mission to Mars were seriously contemplated, it would be imperative first to learn from a long-term colony on the Moon—a lunar equivalent of the British Antarctic Survey. One potential practical benefit of such a colony would be mining: humans are much better at retrieving minerals from the depths than remotely controlled robots.
Another benefit might be the ability to do new types of astronomy. The far side of the Moon is a unique environment for radio astronomy, free from Earthly “noise.” The absence of an atmosphere opens up astronomy across the electromagnetic spectrum. The Moon may make a useful base for high-resolution telescopes to detect Earth-like planets beyond the solar system. Even so, the high costs of using humans to set up and staff facilities on the Moon, as compared with those on Earth and in space, make it unlikely that astronomy would choose the lunar option unless a human presence was already there for other reasons.
Yet another possibility might be to construct launch stations for other missions into deeper space in this low-gravity environment. As Neil Armstrong walked across the lunar surface, seemingly in slow motion as he bounced effortlessly up and down like a yo-yo, viewers were seeing the effects of the Moon’s weak gravitational field. One almost felt that, with a bit of effort, Armstrong could escape into space himself. If human exploration of the solar system becomes a reality, then launching large payloads from its surface could become key.
Would this wider exploring ever be worth it? Considering the dangerous and costly challenges in the way of putting men and women on Mars, we should not assume that the cost-benefit analysis would be easy to pass. Those Martian minerals would need to be very valuable indeed.
And yet, the dream refuses to die. Our stubborn interest in space is relentlessly boosted by Hollywood, and the inspirational value of genuine human space exploration has already had measurable consequences. A major benefit of Apollo was the uptake of PhDs in science and technology in the US. Two groups assessing British participation in Human Space Exploration (HSE), argued some 10 to 15 years ago that the “outreach potential for HSE may significantly influence the interests and educational choice of children towards science and engineering.” Recently, the venture of Tim Peake to the International Space Station has raised public awareness and interest in the UK, and is cited by university applicants as a motivation for their subject choice.
But what will inspire the generation after this? The landing of Nasa’s robotic probe on Mars will help. But if we do want to explore other worlds more thoroughly, then building a long-term colony on the Moon is a necessary first step before any serious exploration of Mars could be undertaken. While my head is clear that the cost is hard to justify, my heart says the challenge is there, the Moon is within reach, and if space exploration is ever to be realised, we have to return to the Moon.
I don’t think I am alone in that ambition—as if to confirm the level of that interest, in the final months of 2018 the Soyuz space capsule was on display in the north transept of Peterborough Cathedral. What better illustration of the human spirit, of our desire to reach for the heavens, could there be? A return to the lunar surface does not seem so outlandish. If there is a bigger surprise than managing to land humans on the Moon successfully 50 years ago, it is that we have never returned.
