Sending people into space is a tough way to make a buck. Not only is it risky, but it's hard to turn a profit given the sky-high cost of rocketing into the upper atmosphere or beyond.

But recently a handful of entrepreneurs, marketers and, yes, even rocket scientists have announced plans to build private space stations, blast astronauts back to the moon, and even mount the first manned expedition to Mars. Just as important, they're looking at new ways to pay for it, including an Axe body-spray promotion that would send 22 contest winners into space.

Led by SpaceX of California, which recently delivered another round of supplies to the International Space Station, the efforts have given rise to hopes that the long-awaited era of private space exploration is, finally, about to begin.

"People are thinking in big terms, which wasn't happening before," said Marco Caceres, a senior space analyst with the Teal Group, which tracks the aerospace and defense industries.

Consider:

•The January sale of 22 suborbital flights by XCOR Aerospace to the parent company of Axe body spray. The flights are the centerpiece of a global marketing campaign, which included a Super Bowl commercial and a contest that has attracted more than 500,000 aspiring astronauts.

• A landmark deal in January between NASA and Bige­low Aerospace that gives the Nevada company a $17.8 million contract to attach one of its inflatable habitats to the space station. The milestone is one step toward the construction of private space stations for use by foreign space agencies and maybe tourists.

• The announcement in late February of a privately financed flyby of Mars set to begin in 2018. Multimillionaire Dennis Tito, the first space tourist, hopes to take advantage of a rare planetary alignment between Earth and Mars to send two people, a man and a woman, on the 501-day expedition.

• Plans to resume human flights to the moon. The Apollo redux missions would cost $1.5 billion apiece and could launch by the end of the decade. Like Bigelow Aerospace, the company Golden Spike aims to attract foreign space agencies and tourists.

Going to the moon

The moon effort is being led by ex-NASA official Alan Stern, who is blunt about the biggest challenge for him and other space entrepreneurs.

"How do you fund this? How do you make a business of this?" Stern said. "That's our Apollo."

Even with an annual budget of about $18 billion, NASA hasn't sent people to the moon since 1972, and it never sent a manned flight to Mars.

By Stern's estimate, it would cost $8 billion to develop the rockets, capsules, spacesuits and other infrastructure needed for the first private trip to the lunar surface. To pay for it, he's trying several ideas.

First he's soliciting wealthy adventurers and foreign space agencies. Next, he intends to turn each lunar launch into the space equivalent of the Olympics, with plenty of advertising and sponsorship opportunities. The company even launched a 10-week crowd-funding effort on the online site Indiegogo aimed at raising $240,000 — a dollar for every mile to the moon.

XCOR Aerospace, a California-based space-plane and tourism company that has considered launching from Kennedy Space Center, is pioneering the marketing of space tourism.

XCOR's sale of 22 flights to the Britain-based Uni­lever Group for its Axe Apollo campaign has raised the profile of its expeditions, which are designed to blast two people — a pilot and a tourist — to 328,000 feet for five-minute stays in the weightless environment of suborbital space.

It's a publicity coup for Axe, which now has a way to advertise directly to the 540,000 people who have signed up for the contest, as well as for XCOR, which has yet to fly a single tourist. Test flights are expected to start this year, with "paid participant" flights, at $95,000 apiece, in early 2014.

XCOR also has a competitor, Virgin Galactic, founded by billionaire entrepreneur Richard Branson, that wants to launch tourists to suborbital space aboard six-passenger space planes for $200,000 each. At least 530 people have made reservations with the New Mexico-based business.