British billionaire Richard Branson and American aerospace designer Bert Rutan are in the Mojave Desert today taking at least some of the wraps off their hitherto top secret MotherShip, WhiteKnightTwo, which is designed to air launch a passenger vehicle out of Earth's atmosphere, The Associated Press is reporting.

Guests, including California Gov. Arnold Schwarzenegger, are gathered to see the MotherShip -- dubbed "Eve" in honor of Branson's mom -- which is designed not to enter space itself but climb to a height of 50,000 feet, then launch a second vehicle, SpaceShipTwo, into suborbit, according to a report on BBC Radio News. 

Today's rollout comes a year after a deadly accident at Rutan's desert test site and marks the start of a rigorous flight test program that space tourism advocates hope will culminate in suborbital flights by the end of the decade, the AP reported.

The twin-fuselage WhiteKnightTwo will have the same wing span -- 140 feet -- as the Boeing B-29 Superfortress, the World War II bomber, according to the AP.

It will launch SpaceShipTwo, the size of a corporate Gulfstream capable of carrying six passengers and two pilots, and both craft are made entirely of ultra-light composite materials, the AP said.

Flight testing is scheduled for the end of September following ground tests in August, according to the AP.

New Mexico officials hope to have space tourism launch from Spaceport America, a $200 million project planned for Upham, 45 miles north of Las Cruces in southern Sierra County.