Thomas Donlan of Barron’s probes one key question missing from the plot of the recent hit movie “The Martian”: Why did the crew of astronauts head to Mars in the first place? It’s a question that directs Donlan to an earlier voyage of exploration.

… [T]his is the season to think of the Mayflower, a venture that had at least two indomitable motivations, liberty and wealth. In 1620, 102 people embarked on a 66-day voyage to a land known as Virginia. They included 40 members of a Separatist church, (who called themselves Saints, not Pilgrims). They were as much concerned with avoiding sinful influences in the Church of England as with escaping religious persecution, but most Americans think of a group of Pilgrim Fathers escaping religious persecution, intent on establishing a shining city on a hill.

None of the Separatists would have made it to Plymouth in 1620 but for the timely support of the London Co., a joint-stock association of speculators that sold shares to establish colonies in North America.

Plymouth, in the investors’ imagination, would become a secure base from which explorers might find the gold that had eluded their company of adventurers in Jamestown.

Nothing was secure about the new colony. In the first few months, half of the people died of disease and hunger. Fortunately for the survivors, the London Co. was beginning to see returns on its investments in Jamestown through planting and export of tobacco back to England. Somewhat encouraged, the company financed more Saints to make their journeys and sent more adventurers to Plymouth.

It would be wonderful—or crazy—to expect NASA to build a Mars colony. The agency has been sketching rockets and habitats like those seen in The Martian since the 1960s, and it has received endorsements from several presidents. But the U.S. has never been so flush with money that it could indulge the adventure. Manned space programs raise public support, but relatively cheap robotic missions can do the science.

As for a modern London Co. of investors and speculators, there are many dreamers, even some very rich dreamers raised on science fiction. Unfortunately, science-fiction authors rarely write about the science of economics. When humanity goes to space to stay, the colonizers will have found ways to create wealth in space and on Earth.