LOS ANGELES — They are celestial missionaries of sorts: professionals with a wild side, celebrities with money to burn and semi-retirees with a hankering for one last thrill.

What they share is a desire to float weightless for five minutes. They've also got $200,000 to book a flight into space.

Even without a guarantee that they would ever blast off, these leisurenauts are voluntarily promoting commercial space travel — still years away — with an almost religious fervor.

The buzz is about Virgin Galactic, the fledgling spaceline founded by British airline mogul Sir Richard Branson. It strategically chooses its clients to be the public face of the company in an effort to corner the infant space tourism market.

Take Trevor Beattie, a London-based advertising guru with a trademark mop of curly black hair. Beattie was in Los Angeles at a space conference this spring hyping a flight he expects to take in 2008 — the program still awaits federal approval and the completion of its rocket ship.

Flanked by Virgin Galactic executives, Beattie gushed about his idol, moonwalker Buzz Aldrin, who was in the crowd.

"When I was a kid, I wanted to be Buzz Aldrin. Now I'm a fully grown adult ... and I still want to be Buzz Aldrin," said Beattie, 46, who has agreed to create for free a 60-second commercial for Virgin Galactic.

In the ultra-secretive world of personal space flight, Virgin Galactic is depending on customers such as Beattie to spread the word. While "founders," as the first 100 Virgin Galactic passengers are known, aren't required to promote the company, many eagerly do.

One is Namira Salim, a 35-year-old artist who splits her time between Monaco and the United Arab Emirates.

Inspired by her founder role, Salim will host an exhibit focused on space tourism in her native Pakistan in September featuring a handcrafted replica of SpaceShipOne, which in 2004 became the first privately funded, manned rocket plane to reach space. Virgin Galactic has contracted with SpaceShipOne designer Burt Rutan to develop the suborbital spacecraft SpaceShipTwo that would initially launch from the Mojave Desert and later at a proposed spaceport in New Mexico.

Salim, who used inheritance money to reserve her seat, chafed at the notion that only the rich can afford to go to space.

"If founders don't make their contribution today, then the common man won't be able to fly tomorrow," she said.

More than 60,000 people have registered to fly with Virgin Galactic since 2004, but only about 200 have paid deposits totaling about $16.4 million, the company said. That money is refundable if flights, which would have six passengers and two crew, never take off.

Its competitor, Virginia-based Space Adventures, which brokered three tourist flights to the international space station, has more than 200 reservations, but only $3 million in escrow. Oklahoma-based Rocketplane Kistler declined to disclose figures.

Which company emerges as the space tourism leader likely will hinge on its safety record — as well as the personalities a company flies into the final frontier who return with gushing tales of seeing Earth from above.

Space tourism experts say they aren't surprised by Virgin Galactic's strategy given Branson's marketing savvy. Though the company says it respects its clients' privacy, it trumps a celebrity founder roster that includes former "Dallas" actress Victoria Principal, designer Philippe Starck and "Superman Returns" director Bryan Singer. (Singer featured a Virgin Galactic spaceship in his movie after contacting Branson about the company.)

The company wants to send 500 people into space in its first year of flights — roughly the same number of people who have gone up in 45 years of space travel.

One is Alan Walton, of Westport, Conn., a 70-year-old daredevil who has skydived at the North Pole, climbed Mount Kilimanjaro and is penning a book about life as a founder that will climax with his trip to the cosmos.

Walton, who emigrated from England with just $10 and made his fortune in biotechnology and venture capital, was among the first to send in his check.

"This is something that I spend every day thinking about — the excitement of doing something that so few people have the chance to do," said Walton.