Should human beings explore? For most of the history of humanity, the answer to this question seemed so self-evident, so obvious that it was never even formulated. Curiosity is such an innate part of our collective character that the answer, for the most part, was always ‘Yes, of course!’ We have always wanted to know what was over the next hilltop just as much as we’ve wanted to understand our natural environment. Over the space of an eye-blink in geological time, the human race left the relative comfort of its origins in the Nile Valley and has now colonised almost every single corner of the planet, from inhospitable desert plains to freezing tundra. Places, for sure, that such fragile and ill-adapted creatures such as ourselves would have been well advised to avoid. Our innate dissatisfaction, our profound inquisitiveness seem to be impulses almost impossible to suppress. But here at the start of a new millennium, the answer to our opening question – should we explore – seems to be increasingly, ‘Well, maybe, for what reason exactly? And don’t you think it’s too dangerous? And don’t we have stuff to do around the house before we leave?’

A remarkable book, Impasse de l’espace, has just been published in France, subtitled A quoi servent les astrounautes?. Roughly translated: ‘Dead end in space: what use are astronauts?’. Serge Brunier, the author, is a well known science writer who has written many eloquent books on astronomy and our collective quest to understand the cosmos. But in his new book – and this is the astonishing part – Brunier spends almost 300 pages attempting to convince us of the utter futility of manned exploration of space. He attempts to drown us in figures, to overwhelm us by what he sees as the sheer impossibility of the human race ever leaving the Earth’s surface. For him, the notion of human agency has vanished; as a species we in fact have no capacity to innovate and we should accept the ‘true’ scale of things. Each wild dream of exploration presented in his book is lasered to pieces by sarcastic prose. He imagines a future in which manned landings on Mars are actually ignored by most of humanity because, in fact, we have already been there. What? By robotic proxies, of course, with their high-bandwidth, full-motion, high-definition video cameras. After all this, Mars would be familiar, no? I would hope that Mr Brunier would be able to distinguish between sitting on the terrace of a cafe in Paris, and looking at the same cafe with ‘Google Earth’ from a satellite dish equipped igloo at the North Pole.

For Brunier, the ‘real’ explorers are the astronomers with their ultra-deep fields of the distant Universe, the digital Lewis and Clarkses wading through terabytes of computer data, the painters of static images of a Universe billions of years distant and completely unreachable. But these explorers cannot interact with their cosmos, and instead should be content to understand it and comprehend it, but not to change it. Moreover, he does not seem to understand that Hubble’s ‘exploration’ of the cosmos from Mount Wilson Observatory was driven by exactly the same impulse that led to Gagarin and Armstrong.

But how did we get to the point where such a point of view could be credible? The history of humans in space is easy to recount and familiar to everyone: at the mid-point of the twentieth century, humans leave Earth’s atmosphere (but not the grip of her gravity) for the first time and circle the Earth in spaceships in only a matter of minutes, not even a century after Jules Verne breathlessly recounted explorers making the same trip in three months. An objective is fixed by the most powerful nation on Earth: to actually land a human being on that symbol of inaccessibility and distance: Borges’ infinite Moon. ‘We choose to go to the Moon in this decade and do other things not because they are easy, but because they are hard’, announced President John F Kennedy.

Men walk on the surface of the Moon, incredibly it seems to us now, only a few short years later. And after that every mission carrying human beings reaches no further than low earth orbit. The frontier point does not extend. Travelling into space becomes a test of endurance rather than adventure. How could it be an adventure if we always visit the same location? Years are spent circling the planet in space stations stuck in low Earth orbit with astronauts taking wistful pictures of the cloud-covered blue-green planet below. Robotic missions explore the furthest reaches of the Solar System, but manned craft go no further than our neighbourhood. The horizon seems to have been forgotten, or worse, is inaccessible.

How can we understand this? Was perhaps the arc of exploration from Gagarin to Armstrong driven by ideology, as many have suggested? In this story, nuclear-armed foes face each other across continents. They must demonstrate that their system, their way of thinking, is superior to their enemy’s. They choose to do this by sending humans to the Moon. And once one system eliminates the other? The motivation is over, of course; the endpoint of the arc is what we thought was only the beginning. From this point, further mis-steps: the Space Shuttle project, designed to be a cheap and reusable way to access Earth orbit, has turned out to be neither cheap nor reusable. It was designed from the outset to carry those kinds of telescopes better suited for observing objects on the ground than in space, for agencies whose names cannot be uttered in the light of noon. Its range is limited to only a few hundred kilometres from the surface of the Earth, even barely outside the atmosphere. Following the Shuttle’s fatal accident two years ago, the International Space Station has become the only acceptable destination for the Space Shuttle because it is the least dangerous. Now, when the Shuttle returns to Earth, great sighs of relief are uttered. It is true that the Shuttle is a complicated and intricate mechanism, but how did we forget that sending humans into space is dangerous?

As an astronomer, and as someone whose work in part relies on data from orbiting satellites, I can easily see I should be appalled by the vast sums of money expended on the human exploration of space. Space-based robotic astronomy missions are a fraction of the cost of manned missions, and provide considerable scientific returns. The current ‘Space Exploration Initiative’ actually provides only a modest increase in funding: at NASA budgets for space science missions are being cut in order to provide for manned exploration. For the time being NASA is locked into a dead end of finishing the International Space Station, which becomes with every passing day more and more like some kind of orbiting zero gravity folly garden.

Despite all this, I still see the value in man himself exploring our Solar System, rather than robotic intermediaries. Imagine a manned expedition to Mars. Perhaps one could attempt to justify such a mission in terms of the vast amount of knowledge it would provide concerning the history and environment of Mars. However, the real reason to go there seems to me to be more than this. Innovation and creativity are driven by adversity, and distant Mars would be one of the most extreme environments human beings could ever experience. Every point on Earth today is only seconds away from every other; it is no longer possible to be lost, to be truly isolated; a satellite communication can always tell us the ‘real’ way to do anything. But, unfortunately, when one explores one goes to places where one cannot be rescued easily if things go wrong. During a three-year trip to Mars there would be no easy return to Earth, and this is precisely the reason why such a trip seems unlikely today. How could a society as risk averse as our own contemplate a voyage like that? The current destinations proposed by the ‘Space Exploration Initiative’ include such backwaters of the Solar System as the Earth’s airless moon, whose sole virtue seems to be that it is nearby.

A recent article published in Discover magazine reminds us, portentously, that we are ‘frail creatures who many not be able to function for long periods outside the gravity, atmosphere and magnetic field of Mother Earth’. Did anyone ever doubt that humans need oxygen to survive? Or water, or air? In another age we would simply have provisioned ourselves well before leaving. And Mr Brunier, when asking if we could travel to the stars one day, reminds us that the first question we should ask is not actually could we do it, but should we do it. I fear that our future ‘journeys’ in space will be in circles around the Earth for some years to come.

Henry J McCracken is astronome adjoint, Institut d’Astrophysique de Paris and Observatoire de Paris