Philae, the little robot that landed on a comet 300 million miles (482 million km) from Earth on Wednesday, may have bounced off a bit. At the time of writing, its handlers are warily considering their next step, wondering whether to attempt to attach it more tightly to Churyumov-Gerasimenko 67P.
But whether or not it sticks, this has been a huge technological achievement. More importantly, it is one more staging post in mankind’s rapid journey away from the surface of its own planet. That is a journey on which each step has seemed impossible when it was made, only to become commonplace within a matter of years.
If you happened to be in Paris 231 years ago, for example, you might have seen something no one had ever seen before: human beings flying, entirely free of the ground. The Montgolfier brothers, Jacques-Etienne and Joseph-Ralf, had discovered the previous year that an upturned silk bag held over a fire rose upwards, and developed what we now call the first hot-air balloon.
And so, on November 21 1783, two men — a chemistry teacher called Jean-Francois Pilatre de Rozier, and Francois Laurent d’Arlandes, a military officer — flew for nearly six miles in the first untethered manned flight, over the suburbs of the French capital.
The flight was going swimmingly until cinders from the fire which was keeping the balloon full started to burn the material, and Pilatre de Rozier put it out with his coat. The gaudily decorated balloon, made out of taffeta by a wallpaper manufacturer named Jean-Baptiste Reveillion, drifted to the ground somewhere outside the city walls. Benjamin Franklin, the US founding father, was present. He wrote in his journal: “We observed it lift off in the most majestic manner. We could not help feeling a certain mixture of awe and admiration.”
The awe is hardly surprising. This was the 18th century, and science and rationalism were in their infancy — the previous year, a woman had been executed in Switzerland for witchcraft. Yet mankind was daring to ascend into the heavens, an almost blasphemous departure from the mortal realm.
No one knew, in those days, whether humans could survive at altitude; Louis XVI, the king of France, had suggested using convicted prisoners for the first flight. Instead, the Montgolfiers used animal trials — a sheep, a duck, and a rooster were sent up, before Etienne and Pilatre de Rozier flew in a balloon tethered on an 80-foot rope. When none of these test subjects exploded or asphyxiated, a manned free flight was scheduled.
Once balloon flight had been demonstrated, it spread throughout European cities, with huge crowds gathering. Within years, the technology had been improved upon, the principles better understood; a balloon filled with hydrogen crossed the English Channel in 1785. By 1795, the French army was already using balloons in war, as an observation post in the Battle of Fleurus.
As humanity has struggled to get itself — and its representatives — ever further from the surface of its planet, this pattern repeats itself. Before something happens, people doubt whether it is possible; then someone does it; then, a few years later, it’s everywhere.
One hundred and twenty years after the Montgolfiers, Orville and Wilbur Wright were trying to become the first men to fly in a craft that was heavier than the air around it. They were far from the first to try: Sir George Cayley, a Yorkshireman, had designed, built and flown a small glider, in 1804. He also established the basic principle of aerodynamics, that if air pressure is lower on the upper side of a wing, it generates lift.
In the century after him, various people tried to use this principle to make a flying machine capable of carrying a human. There were alleged semi-successes in the 1890s, but it was not until December 1903 that the first undisputed powered, manned, heavier-than-air flight took place at Kitty Hawk, North Carolina.
The Wrights’ breakthrough had not been any great insight into physics but a simple, manageable system of control, allowing them to warp one wing or the other, to create more lift and bank the aircraft. The first successful flight made it barely 10 feet into the air, flew about 120 feet forwards, and travelled at less than 11km/h (it was into a headwind). But it counted.
Motor cars were still a novelty, yet restless humans had already used the internal combustion engine to lift themselves skyward. And, again, once the concept had been proved, everyone was at it. It took less than six years for the technology to become mature enough for a 32km flight across the English Channel (a traditional proving ground): the Frenchman Louis Bleriot did so in 1909.
The same year, the US army was experimenting with aircraft for reconnaissance, buying a Wright Brothers-built plane for the purpose. By the end of the First World War, military aircraft were varied, specialised and deadly; in 1919, two British pilots, John Alcock and Arthur Brown, flew across the Atlantic in a modified RAF bomber.
The next huge breakthrough came, similarly, in the aftermath of war. During the Second World War, jet engines began to propel aircraft closer and closer to what some thought was an insurmountable limit — the sound barrier. Several pilots died when their aircraft broke up or lost control as they neared the barrier, because flying faster than sound generates far more drag and heat than flying below it.
But a test pilot called Chuck Yeager, in an experimental rocket-propelled aircraft called the Bell X-1, became, in 1947, the first person known to have flown faster than sound. Seven years later, the first supersonic fighter aircraft flew and fought in Korea; the fastest production aircraft ever built, the SR-71 Blackbird, capable of more than three times the speed of sound, went into service in 1964. The supersonic aircraft went from brand new to unimprovably good in just 17 years.
The march into space happened with similarly unseemly haste. Wernher von Braun’s V2 rocket launched for the first time in 1944; both the Americans and the Soviets copied its design in the immediate post-war years, to develop ballistic missiles.
Then things shot forward rapidly: a modified Russian missile launched Sputnik, the first satellite, in 1955; Yuri Gagarin became the first man in orbit in 1961, and less than a decade later — and still, remember, less than 70 years after the first men got off the ground in an aeroplane — Neil Armstrong put the first human foot on the surface of another planet. The scale and speed of the achievement is entirely unparalleled in human history.
Of course, no human has gone that far since — in fact, if the Earth were the size of a football, no human would have gone more than half an inch from the surface since the last Apollo mission. But instead, we’ve done something better: we’ve sent robots. The Voyager missions have been flying for 37 years. Voyager 1 has left the solar system, and is humanity’s first envoy into interstellar space. But doughty though the Voyagers are, they are primitive creatures, running computers about a million times slower than your iPhone; again, it didn’t take long for things to get better.
The rovers trundling over the surface of Mars are clever, autonomous machines that can make their own decisions about which patch of rock to investigate next. For 200,000 years, the species Homo sapiens was bound tightly to the surface of the rock it was born on.
Less than 250 years after the first of us left it, we are sending robotic envoys to chase comets and head out into the stars. If Philae falls at the last hurdle, it will be sad, but still inspiring. Because history tells us we’ll be back, and doing it better, very, very soon.
The Telegraph Group Limited, London 2014