Martin Rees wonders about the future of manned space expeditions.

The first human on the moon will be remembered for centuries, but the need for people to venture into space has waned. The first arrival of earthly life on another celestial body ranks as an epochal event not only for our generation, but in the history of our planet. Neil Armstrong was at the cusp of the Apollo programme. This was a collective technological effort of epic scale, but his is the one name sure to be remembered centuries hence.

Armstrong spent years as a test pilot, but he didn’t seem a daredevil; indeed his demeanour more resembled a stolid civilian airline captain. He described himself as a “nerdy engineer”, and it was as a professor of engineering that he quietly spent his later life.

Apollo 11 landed on the moon only 12 years after the launch of Sputnik, and only 66 years after the Wright brothers’ first flight. Had the pace been sustained, there would by now be human footprints on Mars. But the moon race was an end in itself, driven by the urge to beat the Russians; there was no motive to sustain the huge expenditure.

Iconic images

The images of Earth’s delicate biosphere, contrasting with the sterile moonscape where the astronauts left their footsteps, have become iconic for environmentalists: these may indeed be the Apollo programme’s most enduring legacy.

It is now 40 years since Harrison Schmidt and Eugene Cernan, the last men on the moon, returned to Earth. To the young, this is all ancient history. They learn that America landed men on the moon just as they learn that the Egyptians built the pyramids, but the motivations seem almost as bizarre in the one case as in the other; the outdated gadgetry and “right stuff” values portrayed in films and news clips of the period seem as antiquated as those of a traditional Western. Manned spaceflight has lost its glamour — understandably so, because it hardly seems inspiring, 40 years after Apollo, for astronauts merely to circle the Earth in the space shuttle and the International Space Station.

We depend on space technology for communications, weather forecasting, mapping, position-finding and so forth quite apart from the science it has given us. But this doesn’t need astronauts.

Closeups of the Martian surface, and of Jupiter, Saturn and their moons, have beamed back pictures of varied and distinctive worlds. In the coming decades, the entire solar system will be explored by flotillas of unmanned craft. Indeed, it is realistic to expect robotic fabricators, building large structures, or perhaps mining rare materials from asteroids.

But will people venture back to the moon, and beyond? The need weakens with each advance in robots and miniaturisation. But deep space still beckons as a long-range adventure for — at least a few — humans.

Perhaps the Chinese will embark on a prestigious space spectacular. For this, a return to the moon would not be enough. To repeat Neil Armstrong’s feat, 50 years later, would hardly proclaim that China had achieved parity with the US. They would surely aim to trump Apollo by heading for Mars.

But would humans on Mars serve a purpose beyond mere prestige? There’s no denying that an observant geologist might make startling discoveries that Nasa’s recently-landed Curiosity rover would overlook. But the current cost gap between manned and unmanned missions is huge.

This is partly because Nasa has become constrained by public and political opinion to be too risk-averse. The space shuttle’s two failures in its 135 launches were national traumas in the US, though that is a risk-level that astronauts would willingly accept.

Indeed Neil Armstrong, who landed the tiny Eagle module with the aid of no more computer power than we have in a washing machine today, rated his odds of a safe touchdown as no better than 50/50. And that wasn’t the scariest risk: the rockets that blasted them off on the return trip could have failed. Indeed, staff of the president, Richard Nixon, had prepared an alternative speech for him to give if Armstrong and Buzz Aldrin had been stranded and perished on the moon.

Future expeditions to the moon and beyond will only be politically and financially viable if they are cut-price ventures, spearheaded by individuals with the right stuff of the Apollo astronauts, prepared to accept high risks — perhaps even “one-way tickets”. They may be privately-funded adventurers. The SpaceX company led by the entrepreneur Elon Musk, has successfully sent a payload into orbit and docked with the International Space Station.

Alien environment

It is foolish to claim, as some do, that emigration into space offers a long-term escape from Earth’s problems. Nowhere in our solar system offers an environment even as clement as the Antarctic or the top of Everest. Nonetheless, a century or two from now, small groups of intrepid adventurers may be living independent from the Earth. Whatever ethical constraints we impose here on the ground, we should surely wish such pioneers good luck in genetically modifying their progeny to adapt to alien environments: the post-human era would then begin. Neil Armstrong, the quiet hero, would then indeed have prefigured “one giant leap for mankind”.

© Guardian News & Media 2012