"Humans to Mars? Why Not?"

By Natalie Angier

Its tallest volcano is three times as high as Mount Everest, and its great rift valley plunges to over four times the depth of the Grand Canyon. Global dust storms with winds up to 300 m.p.h. sometimes obscure its arid surface, which is pocked with vast gulches and deltas apparently left by ancient rivers. And maybe, just maybe, its stones bear fossils of primitive creatures that vanished billions of years ago with the waters that gave them life.

Despite the vivid images relayed by the Viking landers in the mid-1970s, Mars to most people remains a planet of the imagination, as unlikely a home for humans as it is for diminutive green men. To a surprising number of prominent scientists and politicians, however, it is the next frontier, a new world to be tamed and colonized. Gathering in Washington last week for a celebration of the tenth anniversary of the Apollo-Soyuz space linkup were such luminaries as Astronomer Carl Sagan, former Moonwalker and U.S. Senator Harrison Schmitt, Astronaut Sally Ride, Hawaii Senator Spark Matsunaga and NASA Chief James Beggs. They proposed an agenda for the future as well: a joint U.S.-Soviet manned mission to Mars, which could be launched as early as 2010. In the highlight of the meeting, sponsored by the Planetary Society and the American Institute of Aeronautics and Astronautics, Cosmonauts Alexei Leonov and Valery Kubasov, the Soviet linkup veterans, rejoined their Apollo counterparts Tom Stafford, Deke Slayton and Vance Brand to exchange a few emotional bear hugs and put in their own plug for Mars. "If the decision were taken," Leonov said, smiling roguishly, "I wouldn't object to doing it again, with the same men participating."

The hope shared by the spacemen is that by working together toward a common goal, the two nations might somehow put aside their differences. "It's hard to imagine a more dramatic and fitting symbol on behalf of the human species," said Sagan. "We should embrace not the god of war, but the planet named after him."

There are more practical reasons for a joint mission. Neither nation alone can easily afford the estimated $40 billion price tag. And even that figure is conservative; it assumes the existence of the $10 billion orbiting U.S. space station, now scheduled for completion around 1992, which will be used as a platform to assemble and launch the Mars-bound rocket.

Technical cooperation might also ease the engineering difficulties inherent in a lengthy and complex manned voyage. At its closest point, Mars is 35 million miles from earth, or 160 times the distance of the moon. A hypothetical round trip, including a Mars layover, would take two to three years and require a craft that with the requisite fuel, oxygen, solid food and other "consumables" might weigh 500 tons. From ten to 20 shuttle trips would be needed just to ferry to the space station the pieces that would eventually be assembled into a Mars ship.

The stresses on the crew would be unprecedented. Marsnauts could be exposed to high levels of radiation from cosmic rays and unpredictable solar flares. After a long stint in zero gravity, the space crews' muscles, including their hearts, would weaken, and their bones would lose calcium. And it may be inevitable that a small group of people living together in cramped quarters for years would fall prey to loneliness, boredom and squabbling. Admitted Sally Ride, who shared one of her two space flights with six other astronauts in the crowded confines of the shuttle: "You'd have to be very careful about the people you would choose."

Undaunted by these challenges, some space experts have already begun planning the Mars itinerary, devising a variety of baroque flight paths to save on energy and thus fuel. One trip, for example, would require a roundabout swing past Venus, which would lend the craft a gravitational boost in acceleration. On the voyage, the crew module would constantly spin, to provide artificial gravity, and would be equipped with an automatic solar monitoring system and a shielded "storm cellar" in the event-of a solar flare. To give the crew emotional solace in the blackness of space, the interior could be decorated with soothing colors like fawn beige and periwinkle blue.

Once on Mars, crew members could extract the traces of water that still exist in the atmosphere; the water could even be broken into its constituent oxygen (for breathing) and hydrogen (for fuel). Given the planet's abundant supply of carbon dioxide, greenhouse gardening should be possible during subsequent, longer stays.

In fact, some of the apparent similarities between earth and Mars are what makes the Red Planet so appealing a place to visit. A study of Mars could reveal critical insights about the meteorology and seismology of the earth; the strata that should be visible in the walls of the great rift valley would reveal the planet's geological history, exposed and waiting to be read. And the question that the Viking landers could not answer might be resolved: If the planet is so like our own, did life ever evolve there? Whether it did or not, Carl Sagan sees an opportunity for some provocative scientific research on the earth's sister planet. "Life is on one," he says, "and not the other. How come? It is the classic laboratory situation, one the experiment, the other the control."

Even without the rationale of superpower cooperation or scientific benefit, the delegates agreed, human beings will eventually land on Mars, driven by nothing less than good old-fashioned nosiness. "We will never be satisfied with data streams and pictures from some distant planet," said Schmitt. "We want to be there." Concluded James Beggs: "Humans to Mars? Why not?" --By Natalie Angier. Reported by Jay Branegan/Washington

With reporting by Reported by Jay Branegan/Washington