In August and September of 1977, NASA launched two Voyager probes on a journey that would take them further from the Earth than anything else has ever been, previously or subsequently. In the last twenty seven years the Voyager probes have traversed the solar system passing Saturn, Jupiter and Uranus, and will achieve so-called 'termination shock' by passing beyond our suns sphere of influence into outer space.

However, for me, what is most interesting about these two small spacecraft is the 'golden record' that each of them carries. The 'golden record' is a 12" gold-plated copper disc, much like a phonograph record, on which are encoded 118 black and white images and 90 minutes of audio. The golden record is encased in a protective aluminium cover that is inscribed with information supposed to explain to how to use it. As a package, the golden record is intended for extra terrestrial life forms (ETs) that might come across the Voyager; attempting to represent the earth in all its complexity through pictures and sound. It extends Voyager's mission from simply the exploration of the solar system to being a component of the CETI (Communication with Extra Terrestrial Intelligence) program. It becomes a device for communicating with aliens.

My Voyager is an actual size model of Voyager 2 constructed from plywood and assorted hinges and hardware. It is the same size, shape and form as the real Voyager. In fact, it is as close to the real thing as I can make it, within the limits imposed by my very domestic palette of materials. However, my aim is not so much to reproduce the Voyager, as to physically invoke it; to summon the spirit of the Voyager so that we might apprehend it as a physical object.

I would like to say that Voyager belongs to a class of things that we can see anytime but can never see. Unfortunately however, this is a meaningless sentence because English lacks two words that distinguish between seeing something via reproduction and seeing something in the flesh. This is unfortunate because it is precisely this distinction that a thing like Voyager invokes.

Most people who see My Voyager will recognise it as a spacecraft. They may not recognise it specifically as Voyager, or may confuse it as a satellite rather than a probe, but they will see it as a spacecraft. This is not because they have ever seen one in the flesh but because they have seen so many in pictures. (Of course, I exclude visitors to the Smithsonian's Air and Space Museum and actual NASA rocket scientists from this generalisation.) Our understanding of these things, which we see only in pictures, lacks an experience of their physicality, their presence and scale. When Jon Lomberg put together the images for the golden record, he was faced with just this problem. He realised that the ETs would have no idea of the physical size relationship between different images, and was forced to impose a crude dimensioning scheme in an attempt to resolve this.

To a certain degree my desire to physically reconstruct Voyager came from a craving to actually find out how big it was. My Voyager is pieced together from the various, often contradictory, images that I could find in books or on the web. I don't think it is going to fool anyone, and it is probably not very accurate, but then again it is not supposed to be Voyager. It is intended to stand in for Voyager, to represent it much in the same way that Voyager represents us to the aliens.

Alongside My Voyager is an audio work, Golden Record (Fitzroy Remix), which follows the process of My Voyager in reconstructing the golden record using locally available materials. In this case, the work is assembled from recordings of greetings to the ETs, in multiple languages, spoken by people who live or work in the immediate vicinity of our studio in Melbourne.

I hope in some way that this work reproduces the inclusive and optimistic nature of the original golden record, however there is also a degree of transformation that has taken place. I have always been struck by how easy it would be for the aliens to play the record at the wrong speed or in reverse, and how different their experience of it would be as a result. This is a perfect example of the immense, inherent fragility to the whole Voyager project that, for me, only adds to its allure.

Voyager, with the golden record attached, is currently about fourteen billion kilometres from the Earth, making it the furthest distant human produced object in the universe. When Voyager's on-board power source runs out in six years time it will become little more than a very sophisticated message in a bottle. Until it inadvertently runs into something, Voyager will continue its passage through the cosmos pretty much indefinitely. In sixty thousand years it will come within ten trillion kilometres of an unremarkable star named AC +79 3888. This is the nearest it will get to anything in the next two hundred thousand years.

For me, there is something very grand about this gesture, in inverse proportion to its minuscule chances of success. Even if ETs were to find it, figure out how to build a video/audio record player for it, work out which bits to listen too and which to look at and get to it to play at the right speed, it is hard to imagine what they might make of this message from the people of Earth. Within it they would find more than fifty tiny fragments of spoken language alongside traffic sounds and diverse musical moments from Beethoven to Chuck Berry via New Guinean folk music. They would see images of embryos or a not quite built Sydney Opera House, African mud-brick houses and Chinese school children, but no images of violence or war.

Despite the scientific rigour of its conception, I see the golden record is one of the most ambitious pieces of conceptual art to come out of the 1970s. This is an idealistic, if impossible, attempt to be inclusive, to try to represent everybody and everything. It is far more sophisticated than the earlier Pioneer 10 and 11 plaques, which reduced our existence to a diagram of the solar system and a simplified but obviously caucasian couple. Unfortunately, its good intensions do not make it any less impossible, or flawed, a project. However, more interesting than its failure is the way that the scope and ambition of the golden record has transformed Voyager from a utilitarian research vehicle into nothing less than a representation of humanity; a work of art.

In the years since Voyager was launched, the place of space exploration has waned in the public imagination. It is interesting then that it is back on the political agenda. This time it takes the form of the manned exploration of Mars. While it is probably not more than a headline grabber lobed out into the media landscape by G W Bush's political staff, it is an interesting choice. Obviously, it recalls Kennedy's famous pledge to 'put a man on the moon and return him safely to earth', however without the cold war context of a superpower space race. So, in the apparently different environment of post-9/11 USA, why Mars all of a sudden?

It is pertinent to reflect on what drives, and has always driven, space exploration. Obviously, what drove the scientists and engineers at both NASA and Korolev's OKB-I is very different from what drove then to be funded. There is no doubt that the staffs of the various space agencies were on the whole impelled by as pure scientific motives as you are likely to find anywhere. However, looking at the shifting fortunes of the space agencies over the last 50 years, it is clear that it is political requirements and expediencies that engender these shifts. It is a sad irony that space exploration has never really recovered from the point at which the space 'race' became a co-operative venture, and therefore less exciting as propaganda.

To a certain extent, you can't really blame governments. In terms of how they see the world, space exploration, beyond its media value, isn't really that useful. Apart from Velcro and freeze-dried ice cream, what did going to the moon really do for us here, back on Earth?

Paradoxically, I think that it is the very uselessness of space exploration that gives it its symbolic power. In an age where most activities appear suspect or cynical, space exploration remains heroic, pure. You do not explore space for commercial or political gain, and these days there is not really even any military motive. We explore space to know more about the universe. We do it to enrich human knowledge and understanding. There is a beauty in that. Furthermore, those who travel into space to do this, do so with a certain degree of personal risk. There is heroism in that.

I think what motivated G W Bush's people to have him start talking about space is a desire to associate him with something heroic. The idea of exploring Mars is more than just a welcome break from the wars on Terra; it is something both physically and conceptually far from the calumny of Iraq, terrorism or a nose-diving dollar. It is hard to wring much heroism out of military or civilian casualties, lost in the name of weapons of mass destruction that were never there. Such losses are tragic, not heroic.

Yet we still long for heroism. There was a time, not so long ago, when to be 'imperial' was a good thing, and in those days it was easy to be heroic. Fortunately, dying or killing for your country or opening up tracts of 'legally unexplored' land and disenfranchising those who occupied it no longer constitute acceptable heroism. Space exploration however, particularly manned exploration, can provide us with a contemporary form of acceptable heroism. I believe that Voyager, with its grand yet probably futile attempt to carry a representation of the complexity of the Earth and its people to the ETs, is similarly heroic.

My Voyager reflects on the symbolic power of space travel, particularly the way that it functions as a form of representation. It is hard to believe that ETs, if they do discover Voyager, will garner an understanding of the Earth and its peoples that is in any way similar to ours. Judging it this way, the 'failure' of Voyager as an alien communication device seems almost inevitable. However, I don't believe that it ought to be judged in this way. Like all great art, we should appreciate Voyager for the scale of its ideas and its symbolic intensity, rather than its practical efficacy.

Peter Hennessey