The Martians are coming

MISSIONS into outer space used to focus on human drama and the very real dangers involved in sitting on the equivalent of a powder keg and lighting the fuse. Now they would appear to be more about merchandising.

Take a look at the US National Aeronautics and Space Administration's Internet pages about its Pathfinder mission to Mars to sample the change. There you can find offers related to Pathfinder merchandise, available by mail order. The website also tells you about the toy manufacturer Mattel's new Hot Wheels car, a copy of Pathfinder's robot rover, Sojourner. The real rover - hopefully - comes to life over this weekend for a runabout on the Martian surface.

The timing is important. Pathfinder's touchdown on Mars was set for July 4th - US Independence Day - and live pictures from Mars should be available on American television screens over the long holiday weekend.

NASA is getting better and better at marketing its space missions, akin to the way that Hollywood markets films. And the US media will respond in blockbuster fashion, providing hours of coverage, experts to deliver comment and replays of the latest pictures from Pathfinder.

And why not? NASA has learned that taxpayers get restive when asked for a few billion dollars to study cosmic ray penetration of satellite electronics or lattice formation in gallium arsenide crystals formed at microgravity.

Better to simplify things by declaring a search for traces of primitive life on Mars or send pictures of astronauts fixing faulty space telescopes. These activities have easily understood meaning and make it easier to justify risking life and limb while spending astronomical amounts of cash.

Unfortunately, this approach also trivialises the scientific aims of the projects. We lose sight of the remarkable achievements of those on earth who design small, lightweight devices that can analyse rocks on Mars and study their composition. Who cares whether Sojourner gathers data, say the marketing experts? We want to hear about how its controllers will be using virtual reality goggles to direct its motion and see it scoot about on the Martian landscape.

The entertainer approach to manned space travel also serves to diminish the very real threat to life these endeavours pose. Space shuttle astronauts sit atop enough liquid and solid fuel to blow up half of Dublin. The decades of training given to each of these remarkable individuals is not apparent to us as we wait impatiently for the spacewalk promised by the mission controllers.

So should humankind spend money on space travel and satellites and Mars landers? Absolutely. One of the few absolutes in science is that if you go looking you will find something - even if it isn't what you expected. The corollary to this is that if you don't look then don't expect to find anything.

Space science involves "looking" on a whole range of fronts at once. You have to build something to get a person or a satellite into space. To do this you have to build a new kind of engine and develop new types of fuel. You need new lightweight but strong materials for the equipment you will need in space and will have to find ways to protect people from technical failures.

If you are going to be up there you might as well develop new cameras to return high-quality pictures of what is going on. And why not throw in a few exotic scientific experiments that will tell us a bit more about what the moon is made of or whether the rocks on Mars are really red.

Dr Mark Adler, Mars Exploration Programme Architect, based at the Jet Propulsion Laboratory in California which is controlling the Pathfinder mission, has no difficulty justifying efforts in space.

"This is an investment in the future. You have to look to the future," he says. NASA believes that understanding Mars could lead to a better understanding of the Earth and how things might be in the future.

"Mars is extremely interesting in two respects," states Dr Adler. "Mars was similar to Earth in its early history, with both a warm surface and liquid water. But we don't know what happened to Mars that left it dry and frozen.

"The other thing is the question of life. We are interested to know whether life existed there because it would clinch the case that life is plentiful in the universe."

Pathfinder is unlikely to get anywhere near the ambitious goal of answering these two questions, but you have to start somewhere.

And so it comes to missions such as Pathfinder and the multiple spacecraft launches to Mars that will follow. The Mars Global Surveyor will go into Martian orbit in September to begin an extensive surface mapping programme.

Between now and 2005, there will be Surveyor missions either orbiting the Red Planet or landing on its surface. The culmination will be a mission eight years from now when a lander will be sent to the surface to collect rocks and soil before returning to Earth for analysis. This may well decide whether Mars once harboured life, even if only in microscopic form.

Earthly observers have always viewed Mars with dread and fascination, first as a symbol for the god of war, then as a possible home for a Martian super race.

Indications of advanced technology on the planet came from what astronomers described as "canals" on its surface stretching for thousands of miles. Early technologists recognised the spectacular accomplishment" of constructing these extensive canals, and assumed the builders must have been very, advanced indeed.

The fly-by Mariner and the Viking landers NASA missions later showed these Features to be massive fissures. But our obvious appetite for discovering company in the universe was whetted again more recently with the discovery of a meteorite, picked up in Antarctica, and though to have come from Mars.

This four pound, potato-shaped rock may have been ejected from Mars after a comet or asteroid struck the planet 16 million years ago. Inside researchers found features they interpreted as indicating a form of primitive, fossilised life. They published their findings in August last year, only four months before Pathfinder lifted off.

The sceptical might view this as a perfectly timed promotion for the Pathfinder launch last December, but that would really be too Machiavellian. Even so, there is no doubt the coincidence helped heighten expectations of what might be expected from the Pathfinder mission and the work to be done on the surface by Sojourner.

And what of a manned mission to Mars? Dr Adler says that this is on the drawing board for 2014. In the meantime, the current Mars series will provide much useful information in anticipation of this journey. "The programme now has experiments on the 2001 mission that will pave the way for the manned mission to Mars," he says.