McCloskey is not convinced by "the lovely photos from Nasa’s journeys out into the solar system." Dmytro Olegovich Zakharchuk / Alamy Stock Photo

The duel: Is space exploration worth it?

Should we venture out into the cosmic vastness—or put the resources to use elsewhere? Our panellists discuss

Yes—Marcus Chown

Paradoxically, space exploration teaches us about the Earth. And the things that we learn are arguably priceless because they are crucial to our survival.

The critical point is that other planets show us what the Earth would be like if things were different. So, for instance, we can see what the Earth would be like if it were smaller or larger, hotter or colder, if it had a different atmosphere, and so on.

Venus is Earth’s twin in terms of its mass. Yet when space probes visited the planet in the 1960s, they discovered that Venus is actually Hell. Beneath impenetrable sulphuric acid clouds is a surface hot enough to melt lead, and a crushing atmosphere 100 times thicker than the Earth’s. What has happened on Venus is that carbon dioxide, which on Earth is locked up in chalk cliffs, has seeped out into the atmosphere, creating runaway greenhouse warming.

Mars, by contrast, warned us of the danger of catastrophic cooling. When Nasa’s Mariner 9 space probe arrived in 1971, it sent back pictures of an enormous dust storm, reflecting sunlight back into space and dramatically cooling the planet. This caused Mariner 9 scientist Carl Sagan and others to realise that a terrestrial nuclear war would pump smoke from burning debris into the stratosphere and plunge Earth into a devastating nuclear winter.

But not all space insights are so prosaic. The Apollo 8 photograph of the Earth rising above the Moon taken on Christmas Eve 1968 is widely credited with galvanising the environmental movement, burning into our collective consciousness an indelible image of our tiny fragile home lost in the infinite blackness of space.

No—Deirdre Nansen McCloskey

If Elon Musk wants to wander into space at his own risk and expense, great. You can have no more objection to that than to a grocer wanting to stock a new product on her shelves. It may not work out. Hope it does. No sensible economist would want to stop either of them. Trial and error is at the heart of what’s usually called capitalism.

But when the issue is whether “we” should pay for it, I say “no.” Ask what else we should be doing. A bridge to nowhere is a worse use of resources than a bridge to somewhere. Near space is one thing: communications satellites have quickly become commercial enterprises. But in the present state of science and engineering, it’s crazily premature to send rockets into deep space on exploratory missions. Sending people instead of scientific instruments is especially crazy—“Spam in a can,” as the early astronauts described themselves. In two centuries it will be easy to send people to Mars. Now, it is a waste of time and money.

Engineers are trained to be hard-headed about such matters. Is the game worth the candle? Look at the benefits, yes, but also the costs. But space engineers get weepy-eyed and romantic when they speak of the high frontier. They fail to carry out proper cost-benefit calculations.

“In the present state it is crazily premature to send rockets into deep space”

The practice is known to economists as the “Tang Fallacy.” Tang was a horrible faux-orange drink made from a powder to which you added water. It was touted as a spin-off from the space programme (poor astronauts!), which implied Nasa was transforming our daily lives. In reality there was no link. And of course we never saw what technologies might have arrived had ordinary people had that money to innovate with instead of it being wasted on moonshots. Yet High-Frontier romantics try to persuade us to give them trillions by adding Tang to the wonderful benefits of space exploration that we have enjoyed. Let’s not.

Yes—Putting aside the fact that wider knowledge of the cosmos has already alerted us to existential threats to our planet such as catastrophic greenhouse warming, space ventures have provided us with all kinds of things that have benefitted humanity, such as global satellite communication systems and the ability to predict and track hurricanes and forest fires.

Even if the premise is accepted that there are better things to spend money on than space exploration, the question arises: is this really likely to happen? The UK government recently cut foreign aid, in effect arguing “We should spend the money on our own.” But does anyone seriously think that any money saved—whether from axing aid or abandoning space programmes—will be diverted to alleviate child poverty or make food banks unnecessary in the UK?

Human space exploration is, of course, a different kettle of fish to robotic space exploration. For a start, it is a lot more expensive. However, there are things humans can do—like react to unforeseen events—which machines cannot. Maybe AI will be able to do this in the future. But can we wait 200 years? If people had waited until the advent of passenger jets, the world may never have been explored. Technologies build on each other. No castle was ever built without the foundations being laid down first.

Mars once had oceans and rivers and, very likely, simple life. But that has now all gone. “If we are interested in Mars at all,” wrote Ray Bradbury. “It is only because we wonder over our past and worry about our possible future.”

No—You know as much about economics and history as I know about quantum mechanics. But we share a hero, the great physicist Richard Feynman, with whom you studied and whose every book down to his essays on calculation I have tried to study. One of the many things notable about Feynman, you will agree, is that he always asked: How Much? He was never satisfied, to put it technically, with “existence theorems,” such as “There exists a low temperature at which the seals on the Challenger rocket will become brittle,” or in the present case: “There exists something we can learn from deep space.” Feynman would ask How Much.

The refined common sense called economics also asks How Much. You will have none of it. You wave at “all kinds of things that have benefitted humanity,” without looking into costs. In the end you revert to a chorus of praise to the high frontier, on the authority of that learned economist (actually, fantasy author) Ray Bradbury.

I reckon that the rest of us, who pay for this stuff with the pound in our pocket, should question your disdain for vulgar cost considerations. If someone wants to run a private Nasa, good for them. I am enthusiastic about the pursuit of knowledge for its own sake. To quote the poet Wallace Stevens, the “blessed rage for order” does make us human.

But as a society taking practical steps, we need to wait and ask How Much. The jet engine was invented for urgent purposes of war, then it spilled over into commerce. When it was profitable. The Anglo-French Concorde, by contrast, financed with taxpayers’ money, and run by engineers and especially politicians entranced by the high frontier, never justified its cost. It was premature.

Let’s be adult and prudent.

Yes—I am so pleased to discover we share an admiration for Richard Feynman! His nod to pragmatism was always to ask “What can I calculate?” But “What does it cost?” is also characteristic of his nuts-and-bolts view of the world. The cost of space exploration is high, but is nevertheless a small fraction of what the world spends on weapons, which even in 2014 was estimated by the Stockholm International Peace Institute to be $1.8 trillion a year.

But since this is my last contribution, I will venture even further into what you will consider the unworldly. In addition to the tangible benefits of space exploration such as communications and meteorological satellites, there are intangible benefits. How do you put a price on scientific knowledge, inspiration or the expansion of our frontiers?

“What if there had been no Columbus, Shackleton or Scott?”

Space exploration in its widest sense has revealed our place in space and time. Not only do we have a good idea of the extent and content of the universe—we can see all the way to the “light horizon” that forms the boundary of the observable cosmos and count up to two trillion or so galaxies like our Milky Way—but we have a good idea of where it all came from. It burst into being 13.82bn years ago, in a gigantic explosion called the Big Bang.

The big questions remain: are we alone? Is ours the only biology? And that is what the robotic missions to Mars are about. All these intangibles are impossible to cost, and I’ll end with another: what would have happened had there been no Columbus, Shackleton or Scott? In the words of Konstantin Tsiolkovsky: “The Earth is the cradle of humanity, but mankind cannot stay in the cradle forever.”

No—Feynman would have understood that showing space flight is cheaper than an even more foolish expenditure is irrelevant. The drunk justifies his smoking habit by saying: “Well, it costs less than what I spend on booze.” The relevant test is benefit relative to cost. The benefits of near space flight pass the test. How do we know? Private companies are willing to put up satellites. Deep space, and at any altitude human flight, do not pass.

I am very willing to consider the sacred, not only the profane. But we need to get our factual claims about the sacred straight. One can’t just wave at it from afar. “Space exploration in its widest sense has revealed our place in space and time.” No it hasn’t. Telescopes have, from Galileo to Fred Hubble and beyond. The Hubble Space Telescope, corrective specs and all, is in near orbit, not deep space. The lovely photos from Nasa’s journeys out into the solar system are falsely colourised, especially those of remoter objects. Looked at coolly—back to the profane—it’s a PR stunt to extract more trillions.

As to Scott, he was a disastrous idiot. What would have happened without him? Within a few years we could fly to both poles. It beats sled dogs. That’s the point: waiting is prudent on these high frontiers.