By Jim Reed
Newsbeat technology reporter
Sir Richard Branson has designed the aircraft to launch tourists into space.
Sir Richard Branson's Virgin Galactic has taken the wraps off the vehicle that he hopes will launch hundreds of commercial tourists into space.
Guests attended the event in the Mojave Desert in southern California to see the WhiteKnightTwo spaceship unveiled.
The carrier aircraft was officially named Eve after Branson's mother.
It will not enter space itself but climb to a height of 50,000 feet (15,240 metres) before firing a second passenger vehicle into sub-orbit.
Test flights are expected to start later this autumn
At 140 feet (43 metres) the catamaran-style craft has what Virgin says is the longest carbon composite wing ever made and is powered by four Pratt and Whitney engines.
The company reckons it will be able to take off and land up to four times a day and can operate both day and night flights.
Virgin says that work on the eight-person passenger module, called SpaceShipTwo, is now 75% complete.
It is designed to launch from the area between the two carrier pods.
Test flights are expected to start later this autumn with the first paying passengers due to take off next year.
They will travel at four times the speed of sound to a height officially classified as space, experiencing around five minutes of weightlessness before gliding back to earth.
Mr Branson named the mothership after his mother, Eve
Virgin says that more than 250 wannabe astronauts have already put down a deposit for the two-and-a-half-hour flight.
Return tickets are expected to cost around £100,000 each.
Branson has teamed up with the American aerospace engineer Burt Rutan to develop what both hope will be the first commercial space service.
In 2004, Rutan's company Scaled Composites, became the first private venture to send a manned vehicle into space, winning the $10m (£5m) Ansari X Prize in the process.
The technology behind that first vehicle, SpaceShipOne, has been used as the basis for the new airships.