STOCKHOLM — In Europe, the race to take tourists to space has slowed to more of a crawl — with the finish line far on the other side of the horizon.

While in the United States, companies like Virgin Galactic and Blue Origin are closing on a first space mission with paying passengers, in Europe, such trips remain a distant project.

Efforts to fashion new launch sites and bring in rocket ships to carry visitors to the edge of Earth’s atmosphere — some of which were slated to be completed long ago — remain at the planning stage or have been abandoned.

“The old cliché is that spaceflight is hard, and some of these commercial operators who want to take tourists up are finding that out,” said Brendan Curry, head of Washington operations at the Planetary Society, an American nonprofit. “I think that kind of cooled some of the enthusiasm on the Continent.”

This century had kicked with a burst of enthusiasm about space tourism. In 2001, the wealthy American Dennis Tito became the first astronaut to pay for his own trip to space. Soon after, a trio of billionaires emerged with the funds and ambition to offer space travel to anyone with a few hundred thousand dollars to spend on a ticket.

“When people have looked more into the details, it has not been easy to see a good business case in the short run" — Christer Fuglesang, Sweden’s first NASA astronaut

Serial entrepreneur Richard Branson launched Virgin Galactic, which set about developing its own airplane-like spacecraft to fly out of a glitzy hangar in New Mexico. Elon Musk founded SpaceX with one eye on colonizing Mars, and Jeff Bezos’ Blue Origin fired up its own rocket-building project.

The world, it seemed, was “at the dawn of a golden age of space exploration,” as Branson has put it.

In Europe, too, a range of actors tried to tap into the zeitgeist. Private companies began pitching spaceflights that they believed could become a reality within a very few years.

A statement from the 22-member European Space Agency (ESA) in 2008 struck a positive tone and offered support, applauding the private sector’s efforts in “technological development” and pledging to “provide the necessary environment for this industry to flourish.”

But a decade later, this flourishing has yet to occur — as illustrated by the case of Spaceport Sweden.

With its existing base for launching sounding rockets and vast expanses of largely empty territory, northern Sweden emerged early on as an ideal potential hub for European space tourism.

Spaceport Sweden, a company founded in 2007, engaged in talks with Branson’s operation about a tie-up that would see Virgin Galactic’s craft fly tourists out of the northern Swedish town of Kiruna. Its website said — and indeed still says — that the first missions could take place “soon.”

But the years passed and no infrastructure was built and no spaceships took off from Kiruna. The buzz slowly faded as Virgin Galactic’s spaceship program overtook Swedish efforts and went in another direction. In early 2018, local media reported Spaceport Sweden was no longer working with the municipality of Kiruna and was looking for a new base.

Calls to the company went unanswered and Virgin Galactic did not respond to a request for comment on its plans in Sweden.

Part of the problem, experts say, is that the business case for investing in spaceports — which require extensive public investment on the basis that this will create jobs and revenue later — is a hard one to make. So far, no other spaceports have been built yet in Europe.

“When people have looked more into the details, it has not been easy to see a good business case in the short run, and there have been too few politicians who can see the benefits from the many spinoff effects, such as local jobs, increased tourism and research possibilities,” said Christer Fuglesang, Sweden’s first NASA astronaut, who now runs the Space Center at Stockholm’s Royal Institute of Technology.

Phillip J. Stooke, a researcher at the Institute for Earth and Space Exploration at Canada’s University of Western Ontario, said he doesn’t believe there is a market for a raft of small launch sites sending small ships into space.

“There is a drive to build new ones all over the place,” said Stooke. “I think the business is being oversold, and all or most of the future demand will be met by existing launch sites,” he said.

To be sure, the race to build a spaceport in Europe is not over, and some still believe it can be done. The United Kingdom, for one, has emerged as a regional leader in the space sector over the past couple of years and has developed plans for two sites, one in England’s southwest and one in Scotland. Plans for spaceports have also been announced in Italy and Portugal.

Last year, the U.K. government pledged £2 million to fund horizontal space launches from the country, which it called “an exciting prospect.” It envisages grant recipients offering horizontal launch services — which includes launching rocket-powered spacecraft from airplanes which are already airborne — from the U.K. “in the early 2020s.”

Getting a foot on the ladder early could pay off down the line as the space tourism business matures and develops into something that more people can afford, analysts say.

“It is not like it has been all sunshine and roses [at Spaceport America] either” — Brendan Curry, head of Washington operations at the Planetary Society

According to Morgan Stanley, Virgin Galactic’s current space tourism business — which sees a rocket ship launch from and then return to the same site — is already commercially viable and the technology could one day be used to fly people between two points on the Earth at hypersonic speeds. It forecast the hypersonic travel market could generate $800 billion in annual sales by 2040.

But even the one recent successful case of spaceport development to date, Spaceport America, is a further example that setting up new launch sites won’t be easy. The U.S. project took many more years than expected to come online and still isn’t fully operational.

“It is not like it has been all sunshine and roses there either,” said Curry, of the Planetary Society.

“Spaceport America in New Mexico cost a ton of money with the expectation that by now there would be commercial flights zipping in and zipping out routinely and that still hasn’t materialized yet.”