“The first mile is free,” Colorado’s governor, John Hickenlooper, says into a microphone. He’s smiling from a stage in Denver’s air and space museum, backed by a giant American flag that hangs near the bay doors of this repurposed military hangar.

His audience has gathered to celebrate the FAA’s recent approval of a new Colorado spaceport, located a mile above sea level. They laugh at Hickenlooper's statement: They love this catchphrase. High elevation is, after all, Colorado’s claim to fame. And when you’re talking about flinging things into space, starting out 5,280 feet higher actually does make a difference.

Sending things to space is theoretically what happens at a spaceport, though business has been less than bustling. From Colorado's shiny new station, located at the Front Range Airport in Adams County, and the 10 other spaceports in the US, private companies hope to launch rockets and spaceplanes that will carry rich astro-tourists and satellites. But the launch industry hasn’t matured as quickly as those companies had predicted. Which means there's no real need for all these spaceports right now. Of the 90 orbital launches last year, for example, just 29 took place in the US—a load easily handled by the existing sites.

Yet cities keep sprouting spaceports. The Federal Aviation Administration had already licensed ports in Texas, Florida, California, Alaska, Virginia, Oklahoma, and New Mexico, before this Colorado one came along. The problem? Of the 10 active sites last year, only three launched anything at all. "For many of us who’ve been following the commercial space industry for the past 10 to 15 years, I think it’s going slower than everybody had hoped," says Brian Gulliver, aerospace and spaceport practice leader at Kimley-Horn, a consulting group. "We expected more launch vehicles to be operating now."

The first four spaceports were approved in the late '90s, with three more joining them in the aughts, and another four this decade. What they lack in launches, though, they gain in marketing. These cities hope that by some law of attraction, spaceports will draw other aerospace businesses to their locales. And then, when the rockets and spaceplanes are ready, the city will be too. "I’m hopeful that in the future, as launch operations increase, these spaceports will see sufficient activity to justify their investment," says Gulliver. "It’s more of a long-term thing than a near-term thing."

The desire among cities to become a space-innovation magnet is not a secret. Almost two years ago, when I spoke to Dave Ruppel, now the CEO of the Colorado Air and Space Port, he made the case plainly, if in business-speak: “The value for us and for the state of Colorado is to attract companies that will help to build high-tech or aerospace-type technology clusters,” he said.

At the inaugural spaceport event—the result of Ruppel's and others' six-year slog through the FAA application process—others echoed this idea. John Barry, CEO of the air and space museum, projected that the area could become a cosmic version of Silicon Valley: Black Sky Valley. Aerospace Valley.

"I think you just invented a hashtag," said the emcee.

Colorado has a reason to be dreaming about a future space launch industry, even if the business case is currently weak. It's the state with the highest number of aerospace jobs per capita, with Lockheed Martin, United Launch Alliance, Northrop Grumman, and Boeing all calling the state home, along with a healthy smattering of space startups in their shadows.

Though spaceports typically call to mind the launchpads at Florida's Cape Canaveral, the Colorado Air and Space Port is not in fact a rocket spot. It has a horizontal launch license, instead. (The FAA offers both kinds.) Officials describe a time when passengers will buckle into seats on spaceplanes for super-short suborbital flights to Tokyo, shrinking the world. These powerful planes use jet-type engines to take off from lateral runways, igniting rocket engines only after they're high up, and then coasting down to land on a runway after reaching space. Others, like the Stratolaunch plane being developed in California, carry up rockets that they release once in flight. (Colorado doesn't have the go-ahead for that kind of spaceplane.) Horizontal launches are considered less dangerous to the people around the spaceport, and startup costs are often lower: They can be tacked onto existing airports, with their existing runway-and-hangar infrastructure.