An artist's impression of humans exploring Mars. Image credit: NASA/Pat Rawlings

Jul 5, 2015 Spirit that drives our exploration of the Solar System

Sen—Being of sufficiently mature years, I am lucky enough to have witnessed most of the developments in space exploration since it all began in the 1950s.

I was coming up to my fifth birthday when the world's first satellite, Sputnik, was launched by the Soviet Union on Oct. 4, 1957, so I might be forgiven if my recollections of that event are vague. But the launch of the first dog, Laika, into space by Russia, on a one-way trip in November 1957, did register with me.

I recall, too, the blurry but fascinating first images of the far side of the Moon in October 1957, and then the early spaceflights by American chimpanzees, thanks to headlines on the front of my parents' newspaper, the News Chronicle, in the UK.

It was an exciting time to be a youngster, brought up on the adventures of comic book heroes such as Dan Dare, as I witnessed the real flights by Yuri Gagarin, Alan Shepard and other brave cosmonauts and astronauts who became the first humans in space.

The Moon also continued to dominate space reporting, I recall, with close-up pictures of the Moon from the U.S.'s Ranger missions, with their memorable crosshairs, and taken moments before the probes crashed into the Moon; followed by the soft landings of America's Surveyor and Russia's Luna craft. And, of course, the "space race" of the 1960s culminated with the incredible adventure of Apollo, which allowed humans to set foot on the Moon for the first time, in July 1969.

So this week, as I was writing a news story about the exploration of Mars, I paused to think of how incredibly far spaceflight has come in a little over half a century. Back then, many missions to the Moon and neighbouring planets failed, with probes crashing or failing to fly the correct trajectory. Occasionally we were lucky, such as when Mariner 4 flew past Mars in 1964 and showed us it had craters for the first time.

Now here we are discussing the possibility of flying a glider over Mars to help pick a landing site for a new breed of astronaut in the future. There’s a similar plan to fly a powered aircraft through the denser, but acidic atmosphere of our inner neighbour Venus. Other science teams want to send sailboats or submarines to explore the seas of Saturn’s biggest moon Titan, where Cassini scientists have already landed a European spaceprobe, Huygens.

Meanwhile, we are enjoying unprecedented close-up views of a comet as another ESA spacecraft, Rosetta, continues to watch Comet 67P/Churyumov-Gerasimenko with its high-resolution eyes. And of course there is a lander, little Philae, sitting on that comet too.

Other comets and asteroids have been viewed close-up by passing spacecraft, while the biggest asteroid, dwarf planet Ceres is being circled and its mysterious surface features closely studied by NASA’s Dawn mission, just as Vesta was a couple of years ago by the same probe. And, of course, we are just days away from the climax of NASA’s New Horizons mission, which will reveal remote dwarf planet Pluto to us in detail for the first time. Current images from the probe, which has been hurtling through space for over nine years, are already revealing intriguing images of its surface. It will dominate the space news over the next few weeks!

Previously our best views of Pluto had been from the Hubble Space Telescope, another example of an outstanding space mission, that has boosted our knowledge of the Universe, thanks to its orbital location, free of clouds and atmospheric turbulence. And before long, there will be its successor, the James Webb Space Telescope, promising to make even more astonishing discoveries.

When I look back at astronomy textbooks from half a century ago, most of the planets are shown as blurry, low resolution, black and white photos because that is all we had. Asteroids and distant worlds like Neptune, Uranus and Pluto were little more than dots. Today, passing or orbiting space probes have brought us wonderful images of most of the planets, though Uranus and Neptune in particular are in need of much closer study. Mars is being surveyed in exquisite detail, and future missions will take us back to the giant planets to find out more about them and their moons.

Of course, space missions today have a much higher success rate too, thanks to experience and advances in technology. One used to hear, for example, how two-thirds of probes to Mars had failed, but most of those were in the early years of space exploration. We still see launch mishaps, as with a SpaceX Falcon 9 a week ago, that remind us that going into space is never routine, but today’s planetary missions are overwhelmingly successful.

Humans have not even set foot on Mars yet, but already there are adventurers planning daring journeys of exploration across its surface. A few years back, I attended a fascinating talk by Charles Cockell, now Professor of Astrobiology at Edinburgh, on just this topic. Cockell, a co-founder of the Association of Mars Explorers, in 2002, described possible expeditions to climb Syrtis Major, the biggest volcano in the Solar System, and to trek across the planet’s south polar ice cap.

I know I won’t be around to witness such endeavours, but they say much about what has driven space exploration all along—humanity’s need to explore.