The space race is back, and Britain is ready to take its rightful place among the stars. Half a century after the government cancelled "Blue Streak", its ludicrously named rocket programme, the British National Space Centre - like NASA with more tea and less money - has announced a series of workshops to re-examine the possibility of putting a Briton in Outer Space. Science minister Malcolm Wicks has described space missions as "the great adventure of the millennium".

This might not sound like much, but after decades of no interest it is a revolution. It is surely only a little while before the Union Jack flies proudly and rightfully over the cold grey of the moon, the red plains of Mars, the steaming, alien-infested swamps of Venus... As you can see, any discussion of a British space programme has to instantly degenerate into taking the piss. Us in the freezing vacuum? Britain shuts down under a light dusting of snow.

Thanks to privatisation, getting a train from London to Birmingham is such a lunatic thicket of contradictory rules, cancellations and deals it's easier to walk. Tube maintenance is handed to Metronet, whose performance is so crap that even the official arbiter of "public-private partnerships" is compelled to tantrums. This is the "transport vision" of a government and its corporate pals that now want to get a rocket to the stars. I wouldn't trust them to push a wheelbarrow to a shed.

Traditionally the left has excoriated space programmes as militaristic wastes of money. This reaches a searing high point in the 1969 song by The Last Poets, famously covered by Gil Scott-Heron, Whitey on the Moon:

"How come there ain't no money here?

Hmm - Whitey's on the moon.

You know I just about had my fill

of Whitey on the moon.

I think I'll send these doctor bills,

airmail special, to Whitey on the moon."

Even in these degenerate days of piddling shuttle junkets, NASA's annual budget is roughly $15 billion, and it's hard not to think of better uses for that kind of money.

But I have a guilty confession. Despite all that, I cannot bring myself to be against space exploration.

In practice, of course, the government will execute any programme with such cack-handed venality that it'll be a disaster, but that's not a reason to oppose it in principle, only to demand that it be done right. And with all sincere admiration to The Last Poets, the cost of war eclipses by a scale of huge magnitude any payouts to space science. If we're going to question priorities, the issue's not Whitey on the Moon but Yankee in Iraq.

I can't help it: I'm a science fiction fan. I think it says something exciting about humans that we want to explore space. I think there's something wonderful about rocket ships. Above all, I think there's something unspeakably cool about aliens, and I would dearly love to meet them.

Some lefties have gone even further. At about the time Whitey on the Moon was written, Juan Posadas, an influential Argentinian Trotskyist, issued his pamphlet Flying Saucers. According to him, the existence of UFOs proved that more technically and thus socially advanced societies, which could only be socialist societies, existed out there. "We must call upon beings from other planets when they come to intervene," he insisted, "to collaborate with the inhabitants of the earth to overcome misery".

The rest of the left greeted this with baying derision. However, as not enough comrades are SF fans, they misunderstood why Posadas was wrong. The problem is not that he believed in aliens, nor that he thought them our superiors. The problem is that he drew the wrong political conclusions.

The American Marxist Hal Draper famously described the "two souls" of socialism as being the democratic tradition of socialism from below versus the elitist conception of socialism from above. As his quote shows, Posadas not only looked forward to visits from flying saucers - he demanded