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...