As mentioned in this column yesterday, Pioneer 10 is gone. Attempts to contact it have ceased, and even if it could send a signal back to Earth we will never hear it. It's on its own, out in the interstellar void, on its way to Aldebaran; stuck to its side is a plaque designed by Carl Sagan, who is also gone. One wonders if the probe would have been better served by sealing Carl Sagan himself inside it; sedated so as to survive the harsh conditions of deep space. Sagan would be the perfect ambassador for the human race - articulate, intelligent, and slow to anger, it would be easy for him to exchange knowledge with alien beings. Furthermore, as a master swordsman, he could defend the probe from space pirates of a type common in the vicinity of Taurus.

The Pioneer and Voyager probes provoke an odd mixture of emotions amongst space enthusiasts. On the one hand they are plucky little explorers, 'the little engines that could', machines that have long outlasted their designed lifespans and which will almost certainly outlast us. The thought of the probes whizzing through empty space stirs the heart, their transmitters faintly sending a few last kilobytes of information as their reactors cool off, having done a job well done. They are a favourite dog. A spectacularly successful favourite dog. They increased our understanding of the moons and planets of the outer solar system by an incredible amount; their cameras saw more and filled more blanks than any other cameras in history.

There is always the possibility that we might see them again; we know roughly where they are, and if an inventor in a garden shed somewhere comes up with a viable, energy-efficient near-light-speed stardrive - perhaps involving a copper bath and some lemons - we could go and fetch them. Would we scoop them up and put them in a museum, or let them be? If we revisit the moon, will we preserve the lower half of Apollo 11 and its toppled flag as they are?

My instinct says that we will never see Pioneer 10 again. It has a big head start and the money has turned away from space exploration. We have mobile phones, GPS and satellite television; with genetic engineering we might one day abolish death, and thus time - perhaps then interstellar travel will be viable, even at greatly sub-light speeds.

There is the minutest possibility that alien eyes might contemplate it one day. Carl Sagan probably envisaged enlightened beings deciphering its secrets, and setting off to visit Earth, to extend to us the hand of friendship that the man on the plaque extended to them. He did not envisage aliens blowing it up for offending their religion, he did not envisage the probe starting off a war over its ownership, and he did not involve it being swallowed by space whales, although all these possibilities are equally valid.

On the other hand, the probes provide useful ammunition for opponents of manned space programmes. If people had been sent to Saturn, or Jupiter and Beyond the Infinite they would have taken even more photographs than Voyager and made even more readings, but at enormous cost, and with the ever-present risk that the shipboard computer might go haywire and murder most of the crew, or that Jupiter might implode into a star. Or that the pilot would go mad, murder his crewmates and send the biodomes floating off into deep space, tended only by two small robots. Even today astronauts have an aura about them; they are going faster and further than people have ever gone. But space will one day lose its glamour, and space workers will be no more exciting than oil riggers or deep sea divers; people will respect them on those terms, as highly-paid tough guys, but not as avatars for a New Age.

And Pioneer 10 is proof that the machines last longer, because they are better. White kids want to be 50 Cent, Michael Jackson wants to be Peter Pan, but I want to be a machine. Impervious and immortal, able to freeze time and replace my arms with better arms. Biology is messy and imprecise, it goes wrong and can't be fixed. Machines do not have these problems. The individual B-52s in America's air force will outlast 97% of the population of this planet by the time they are retired, assuming there isn't a wicked cool massive war that kills lots of people, in which case they will die with the rest of us. Pioneer 10 will just carry on.

The notion of progress itself seemed to fall apart after Apollo, as we hit a brick wall in terms of unknown horizons and undiscovered countries. Was there ever a time when the majority of people in the West believed that the world was going to get better over time? We get the impression today that people in Victorian Britain or in America in the 1950s thought that the world was their oyster, but did they really? I have no idea. There was plenty of dystopian fiction in the 1950s and 1960s, but I believe that was underpinned by the certainty that the present day was too good to lose, and that it would be horrible if that was to happen, because we had a lot to lose.

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Rather like Kiss and Pet Rocks and that Elian child, Jesica Santillan was huge in America for a while but made little impact in the UK. Nonetheless her case has been a fascinating one from the dispassionate viewpoint possible on this side of the Atlantic. As I understand it the present system of organ donation involves a waiting list, or a lottery, I'm not sure, and the people at the head of the list get the organs, and there has been some controversy that an illegal immigrant has potentially condemned two American citizens to death, albeit not deliberately. I suspect that, had Jesica been fatter and older and a man, the story would not have been newsworthy. Fat old men die all the time.

If we are to accept that the allocation of replacement organs is essentially a lottery, and that Jesica received publicity and therefore a second chance at life because she was a young, attractive girl, and that news is entertainment and vice-versa, it seems to me that future incidents of this nature could be extremely popular reality TV game shows. There would be a selection of transplant patients, each competing for the ultimate prize; the prize being the rest of their life.

A young, teenage, female 'star' would be the bedrock for the series cast mix. Television audiences sympathise most with women as society teaches us that women are vulnerable and pure of heart. She would be of indistinct ethnic origin; perhaps Latino, as minority groups are also sympathetic because society teaches us that they are oppressed. The most obvious cast addition would be an attractive teenage boy to keep our heroine company. This would be an extremely effective 'hook' for the viewing public; not only because young love is compelling, but because one or other of the parties would be doomed to death, thus leaving the surviving teenager with a bitter-sweet legacy. If the voting system could be arranged in such a way that the teenage boy chooses to sacrifice himself in favour of his partner - because men are, after all, the dominant gender and are expected to pull more weight - that would be superb.

(The producers might baulk at such a depressing ending, in which case a 'Joe Millionaire'-style surprise, in the form of an extra set of organs, could be introduced after the boy has made his choice).

Of the other contestants there could be a stoic old black man who accepts his fate with quiet dignity and who would act as a 'father figure' to the young couple; a well-off middle-aged white woman who would be the 'villain', as she is a spoiled shrew selfishly clinging to life; a fat teenage computer person called Josh who would provide comic relief and a variety of other characters who could be introduced and removed at will. This will come to pass eventually; why not now?

The theme song would be 'Should I Stay or Should I Go' by The Clash; now that Joe Strummer is dead, rights issues should not be the problem they might once have been.