The British entrepreneur said on his blog that Kutcher, star of television comedy "Two and a Half Men," will take a ride on a Virgin Galactic flight into suborbital space, which gives passengers a few minutes of weightlessness.

"I gave Ashton a quick call to congratulate and welcome him. He is as thrilled as we are at the prospect of being among the first to cross the final frontier (and back!) with us and to experience the magic of space for himself," Branson said on his blog.

Virgin Galactic, a part of Branson's Virgin Group of companies that includes Virgin airlines, expects to test fly a spacecraft beyond earth's atmosphere this year with commercial passenger service to follow in 2013 or 2014.

Kutcher was the 500th person to sign up for rides on SpaceShipTwo, a six-passenger, two-pilot spaceship being built and tested by Scaled Composites, an aerospace company founded by aircraft designer Burt Rutan and now owned by Northrop Grumman.

The suborbital flights cost about $200,000 per person, are designed to reach an altitude of about 68 miles, giving fliers a few minutes to experience zero gravity and glimpse earth set against the blackness of space.

Branson said he and his children will be on the first commercial flight and considers Virgin Galactic, which is the most visible of a handful of companies developing spaceships for tourism, "the most exciting business we have ever launched."

A spokesperson for Kutcher did not return a call seeking comment.

Kutcher, 34, took up a new acting job replacing Charlie Sheen on "Two and a Half Men" this past September.

(Reporting by Christine Kearney, Editing by Bob Tourtellotte)

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