Blasting DNA samples out into the unknown might not be a good idea, says David Whitehouse. Someone, or something, could decide to use them
SOMETIME in 2001 a series of satellites will be lofted into Earth orbit by an Ariane 5 rocket. Two of the satellites are for communications, and will remain in orbit around our planet, but one - the Encounter spacecraft - will orbit for weeks, perhaps months, waiting for an optimum trajectory to the giant planet Jupiter. Then the spacecraft's escape engine will fire when the Earth and Jupiter come into proper alignment.

It'll need two years to reach Jupiter and once there it will use the planet's gravity to fling it on a trajectory to take it out of the solar system. Again, there's nothing unique about this, except that the Encounter spacecraft will be carrying DNA samples from 4.5 million human beings.

The company behind it thinks it's a great idea. "Encounter 2001 is the first opportunity for all of us to reach out beyond our solar system with our dreams, thoughts, and essence," says spokesman Charles Chafer. (As you might have guessed, it's an American company.)

Individuals will be charged $50 to submit six strands of hair along with their digitised picture and a small message for launch, says Mr Chafer, who is president of Encounter 2001. He's also president of the Celestis Foundation, affiliated with Houston-based Celestis, Inc., the same company that has made a business of launching symbolic portions of cremated remains of humans into orbit for "space burial".

The other partner in the Encounter 2001 venture is AeroAstro, a company with experience building small innovative spacecraft. It could be a very profitable venture. The Encounter 2001 corporation formed by Celestis and AeroAstro hopes to realise $75-225m. Initial market studies by the project indicate 1.5-4.5 million people world-wide could pay $50 to participate in the flight.

"Spacecraft development and launch costs are estimated at $10-12m and the Encounter 2001 project has already secured the $500,000 in financing," said Jim Spellman, one of the West Coast representatives for Celestis Inc. "No additional financing will be required if public response equals our expectations. A final decision to proceed with the project is set for later this year, and spacecraft fabrication is expected to begin the first part of 1999."

The group last week signed a contract to run a series of advertisements across the US, starting this month, to obtain more precise market data.

Now space is vast, and the size of the interstellar spaces is beyond anybody's real comprehension, even if they can write the distance in miles between the stars. This means that Encounter 2001 is almost certain to drift among the stars practically forever as its DNA cargo degrades into basic elements.

But note the word "almost". It is not impossible that the DNA of humans, the blueprint of all human life and a template for all forms of life on Earth, will be picked up by an alien form of life which may find it quite interesting. Do we want that? It may be highly unlikely; but no sensible scientist would say it's impossible.

That raises the question: is it right that our DNA should be dispersed into the galaxy with no sanction from any international organisation? Shouldn't we have a say in this venture? In a real sense, the DNA on that spacecraft will be yours and mine, as the genetic differences between individual humans are minimal compared to the similarities.

But the plan doesn't stop at that. Just in case there are any aliens out there - friendly or not - and just in case they may have missed mankind's genetic gift drifting by in the interstellar dark, Celestis plans to go one stage further, by telling them it's coming. "The mission would be preceded by radio telescope transmissions beamed from Earth - radioing, in effect, `Here we come, ready or not' - to any intelligent life form in deep space that might take an interest in the hair/DNA mission," Chafer said. Those transmissions are to start as early as 31 December.

Is this the celestial equivalent of saying to a wild tiger "eat me"?

Last year an American science-fiction cable channel wanted to broadcast a greeting from Earth into the sky. Scientists the world over said that it would be a bad idea. Firstly, there would have been no discussion about it, and secondly it might just possibly alert whomever (or whatsoever) might be out there to our presence.

There is, of course, the argument that if there are any aliens out there, then their advanced technology would have enabled them to detect our presence already from our leakage radio radiation and if they were really determined to get our DNA they could have clandestinely come here and got it. Sounds like alien abductions? But it's just a very debatable hypothesis - in contrast to the very concrete fact of the human DNA spaceprobe.

Sure, the DNA will decompose. But who knows what's possible with advanced civilisations' technology - which, as Arthur C. Clarke once commented, would seem to us "indistinguishable from magic"?

It might turn out like Jurassic Park, except that this time the roles might be reversed, from one where the humans recreate dinosaurs from their DNA. And what if they think we taste nice?

Dr David Whitehouse is the BBC's Science Correspondent