Race To Mars?

By LEON JAROFF

For I dipt into the future, far as human eye could see . . .

Saw the heavens fill with commerce, argosies of magic sails . . .

-- Alfred, Lord Tennyson

Tennyson's 19th century vision, described in his poem Locksley Hall, could become 20th century reality if an international group of space buffs has its way. In the U.S. and Canada, in Europe and Asia, teams of scientists and designers are busily completing plans for innovative craft that will travel through space propelled solely by sunlight reflecting off their giant sails. At a meeting this fall of the International Astronautical Federation in Dresden, Germany, at least three of the ships will be picked to compete in a fantastic voyage: an unmanned sailing race to Mars.

It may smack of science fiction, but the planners are deadly serious. The race is being sponsored by the Christopher Columbus Quincentennial Jubilee Commission, which hopes to get the ships launched around Oct. 12, 1992, the 500th anniversary of the discovery of America. Among the spacecraft designers are former NASA and aerospace experts. And included on the committee that will choose the winning designs are Lieut. General James Abrahamson, former head of the Star Wars program, and former astronauts Frank Borman and John Glenn.

If all goes according to plan, the competition winners, each weighing 500 kg (1,100 lbs.) or less, will be launched by rocket into Earth orbit. There, high above the atmosphere, each will unfurl a giant sail consisting of wispy plastic coated with a film of aluminum. Positioned by radio signals from the ground, the sails will catch the gentle push of sunlight.

Gentle, indeed. Scientists estimate that photons of sunlight falling on an area the size of a football field exert a pressure equal to the weight of a marble. Yet in the vacuum of space this tiny force is sufficient to accelerate the sailship.

"It will be very slow," admits Emerson LaBombard, project director for the space sailer being developed by a U.S. team at the World Space Foundation in Pasadena, Calif. "In the first hour, we may zoom ahead and pick up a yard. In one day maybe 100 yards." But the acceleration would continue, ultimately resulting in speeds far in excess of 100,000 m.p.h. -- and without expending a drop of rocket fuel.

Increasing their velocity in Earth orbit, the spacecraft would spiral out from the planet, eventually swinging by the moon for a gravity assist that would hurl them into a trajectory toward Mars. Depending on their route and design, they could take as little as 500 days or more than 800 to reach the red planet.

The concept of a space sailing race first surfaced in Arthur C. Clarke's 1963 story The Wind from the Sun, about a seven-craft regatta to the moon. And in the mid-1970s, scientists at the Jet Propulsion Laboratory in Pasadena actually designed a sophisticated sailship to rendezvous with Halley's comet, but a NASA budget squeeze killed the project.

Lack of financing may also be fatal to the Mars race. The Jubilee Commission has placed the burden of fund raising on the individual teams, which must spend anywhere from $3 million to $15 million to complete each entry. Boosting the sailships into orbit is another worry; rocket launches are prohibitively expensive for most teams, which are desperately seeking help. Robert Staehle, head of the World Space Foundation, flew to Paris last month for a workshop with teams from Europe and Asia. The goal: a proposal to the European Space Agency for piggybacking the sailships on a 1992 Ariane rocket flight.

Even if the Mars race fails to come off, Staehle says, his group plans to fly a test sail in space, "operating on a shoestring, if necessary," to prove the concept of space sailing. Eventually, he is convinced, great sailships will ply the trade routes between Earth, the moon and Mars and even fly to the stars.

With reporting by Edwin M. Reingold/Los Angeles and Stephen Sawicki/Boston