`Sunjammer' Totes Memos to Mars

Spacecraft powered by huge solar-driven `sails' will carry recorded messages from Earthlings

VOYAGER spacecraft heading toward the solar system's edge carry discs with recorded sights and sounds of Earth. Now a new space archive is to follow their example. It's SpaceArc - a book-size package with personal statements from anyone who wants to participate. It is to ride into space in 1992 on board a sailing ship propelled by the pressure of sunlight just as a sailboat is moved by the wind.

Like the Voyager discs, SpaceArc can enlighten aliens who may find it. But copies will also be available on Earth.

The Rochester (N.Y.) Museum & Science Center has developed the archive for education and imaginative fun. As explained in the project's recent announcement, the museum is encouraging teachers in all countries to use it for class projects in which students can think of themselves in a global perspective. But anyone can deposit a message for the cost of a $2.50 processing fee. The project brochure illustrates this challenge to communicate across time and space by juxtaposing ancient cave art with the image of a spiral galaxy.

SpaceArc celebrates 1992 both as International Space Year and as the 500th anniversary year of Columbus's arrival in the Americas. The Christopher Columbus Quincentenary Commission has given it ``official project'' status. The museum's partners include the Educational Testing Service, Loral Space Systems, the National Aeronautics and Space Administration, The US International Space Year Association, and the World Space Foundation.

The foundation will supply the solar sailboat. This, too, is part of the space year and Columbus celebrations.

Measuring about 55 meters (180 feet) on a side, the square sail will be about four times the size of a baseball diamond infield. Sunlight pressure on that area will provide only 2.4 grams (0.005 pounds) of force. Yet that relentless little thrust can accelerate the craft by around 20,000 kilometers per hour (12,000 miles an hour) per year. The craft is entered in two races - one to the moon (the Columbus Jubilee official race) and one to Mars. However, because of a dearth of sponsors, it is unclear how many craft will go to Mars.

Foundation project director Emerson LaBombard says the moon race seems on track. The foundation entry, a French/Spanish entry, and possibly a Japanese craft are to be launched on a European Ariane rocket. Mr. LaBombard adds that the foundation craft will go on to Mars.

This is not a recent initiative for the foundation. The solar sailing team has been working on the concept and design of the craft since 1979. Its members are as concerned to demonstrate the practicality of solar sailing as a low-cost space science tool as they are to win the 1992 race, LaBombard says. The foundation's team now has several industrial and university partners plus the Planetary Society and the Radio Amateur Satellite Corp., which will have a ham radio satellite package on board the craft. LaBombard says these partners give the project considerable technical and scientific strength.

While the foundation still is ``rattling around with its tin cup,'' LaBombard says he feels confident the money will be in hand to start the spacecraft's final design and construction in January. He notes that SpaceArc will be launched in any event. As a backup plan, it has assured space on a commercial satellite.

He says: ``The really terribly important aspect of the whole thing we're involved in is to be an inspiration to the future generation. And SpaceArc is just that.''