LOS ANGELES (REUTERS) - Here is a brief look at Richard Branson's Virgin Galactic, which suffered a setback on Friday to its plans for a new era of space tourism when its experimental spaceship crashed during a test flight in California:

SpaceShipTwo was designed and built by Scaled Composites, a Mojave, California-based subsidiary of defence contractor Northrop Grumman.

Virgin Galactic is owned by Branson's London-based Virgin Group, with outside investment from Aabar Investments, which is controlled by the Abu Dhabi government.

So far, Virgin Galactic has spent about US$500 million (S$643m) developing SpaceShipTwo, and it expects to burn through another US$100 million before commercial service starts.

The company had planned on making its first test flight beyond the atmosphere before the end of year.

Nearly 800 people, including actor Leonardo DiCaprio and physicist Stephen Hawking, have signed up for the six-passenger flights - costing US$250,000 per person - which were targeted to begin in 2015 but could now be delayed.

Each passenger is to get a window seat with another window overhead.

"I think most people in this world would love the chance to go to space if they could afford it and if we could guarantee them a return ticket," Branson told NBC in 2013.

Flights are to leave from a sleek, purpose-built commercial spaceport under construction in New Mexico, designed by British-based Foster + Partners.

Space travel is just the latest adventure for Branson, 64, a London-born high school dropout and billionaire. Branson is one of the world's most famous entrepreneurs whose business empire ranges from airlines to music stores and mobiles phones.

His Twitter page describes him as a "Tie-loathing adventurer and thrill seeker, who believes in turning ideas into reality. Otherwise known as Dr Yes at @virgin!"

In 1987, he became the first man to cross the Atlantic ocean in a hot air balloon, and accomplished the same feat across the Pacific in 1991. But his several attempts to circumnavigate the globe in a hot air balloon fell short.

Branson has said he plans to be on the first space flight with his two children, though his daughter, Holly, is currently pregnant. The flight is due to be broadcast live on NBC.

Branson was knighted in 2000 and has an estimated net worth of US$4.9 billion, making him Britain's sixth-richest resident, according to business magazine Forbes.