With the Voyager 1 probe being the first man-made object ever to leave our solar system, James Coghlan explains what this means for mankind’s great journey into the final frontier.
For all its shortcomings, humankind has managed to achieve a remarkable amount in its rather short existence; in the last five hundred years alone, man has circumnavigated the globe, investigated both poles, and conquered the highest mountains the Earth has to offer. We have climbed every mountain and forded every stream. There is nothing we cannot do – we are unstoppable.
As the first human to look at the place we call home in all its splendour from the surface of another celestial body, one could forgive Neil Armstrong for thinking something along those lines as he stamped his name onto the story of the human race. The culmination of nine years of development, the Apollo 11 mission touched the dreams of millions of people around the globe and forever changed their perceptions of what it means to be human. Not since the launch of the first man-made object into outer space has the potential for extra-terrestrial discovery been so greatly enhanced. But the journey did not stop there.
In spite of the enormity of each of our achievements, mankind has managed to out-do itself time and time again, endlessly increasing its capacity for knowledge and enhancing its appetite for adventure. Everyone thought that the field of science and technology had reached its peak, but eight years after our greatest achievement as a species, the story was no different.
Little did the men and women working on NASA’s Voyager programme know that the probe designated Voyager 1 would go on to penetrate the outer reaches of our solar system’s heliosphere and become the only man-made object in history to enter interstellar space. If that isn’t amazing enough, here are some eye-watering facts: it has been in service for 36 years – hurtling towards the stars at a peak speed of 62,136 kilometres per hour – and has travelled almost 19 billion kilometres, a distance so large that it takes 17 hours for radio messages to reach Earth. That means the probe is 126 astronomical units away from home. Translated into plain English, that’s 126 times the distance between the Earth and our Sun.
Quite an impressive achievement then, especially once you consider that a modern-day sound system can possess more than five times the power that Voyager 1 currently has. However, in spite of its relative technological crudeness, the little probe has a lot riding on its shoulders. Voyager 1 was originally intended to study the planets of the outer solar system, but has recently been burdened with the responsibility of being NASA’s only source of information within interstellar space. No pressure, then.
To be honest, there could not have been a better-qualified piece of equipment for the job. It overtook its sister probe Voyager 2 – launched some two weeks before it – and became the first probe to discover Jupiter’s planetary rings, along with volcanic activity on its moon Io.
It was also the first to capture high-resolution images of Saturn’s moons, identifying surface structures never seen by the Pioneer probes. So, even before it assumed the mantle of being mankind’s most important far-flung creation Voyager 1’s journey had been immensely productive, the information gathered by the probe enough to rewrite astronomy textbooks. Were the people behind the project satisfied? In one word: no. Like all humans, they wanted more.
Having completed its flybys of Jupiter and Saturn, Voyager 1’s planetary mission came to an end. However, instead of decommissioning the craft NASA chose to direct it past Saturn’s giant moon Titan. This flyby deflected the craft in such a way so as to remove it from the plane of the ecliptic, sending it off into deep space. NASA could have directed the probe to Pluto to complete its part of the Grand Tour, but they didn’t. Voyager 1 was destined to explore more than our home turf, and NASA knew this; the capabilities of the probe extended far beyond the tasks originally assigned to it. NASA’s intentions must have stretched just as far, seeing as both of the probes left this world carrying golden records containing sounds and images selected to portray the diversity of life and culture on Earth. There is no question that NASA intended for these probes to extend the domain of the human race, in both discovery and spirit.
Armed with increased funding and carrying a symbol of human achievement, Voyager 1 hurtled into the unknown and, as we discovered in September, entered interstellar space on the widely agreed date of August 25 2012. It was on this date that changes in the density of charged particles were first detected, thus suggesting that the craft had finally left the clutches of the heliopause at the edge of our solar system and entered the unknown. This date carries with it yet more significance, however, as this was the exact date on which the world lost its greatest pioneer: Neil Armstrong. Perhaps it is fitting that as one great trailblazer passed from us, another took up its mantle; the sense of adventure and discovery was not lost, but passed on. Human endeavour is characterised by one achievement superseding another, and this is exactly what Voyager 1 represents.
The probe is set to continue transmitting data to Earth until 2025, at which point its on-board power systems will not be able to support any of its instruments. Until then, it will inform our understanding of the medium beyond our solar system, providing solid data where before there was only indirect evidence and models.
Naturally after such a momentous achievement there is only one question on my mind: where do we go from here? There are proposals to send autonomous spacecraft to nearby stars, but such vehicles would take centuries to reach their destinations, not decades. Having said that, the human race would not be where it is right now if it did not out-do itself. With Voyager 1, it is safe to say that we have out-done ourselves yet again.
James Coghlan
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