Key Points:

Paris Hilton, who has paid a reported US$200,000 for a seat on an intergalactic flight, is scared of going into space in case she doesn't return for 10,000 years.

The socialite is one of many celebrities - believed to include singer Moby, Star Trek star William Shatner and Alien actress Sigourney Weaver - hoping to board Richard Branson's first-ever commercial space flight, Virgin Galactic, but admits she is worried about going into orbit.

She said: "I'm very scared to do it. What if I don't come back? With the whole light years thing, what if I come back 10,000 years later, and everyone I know is dead? I'll be like, 'Great. Now I have to start all over.'"

An estimated 157 people have signed up to take the flight, paying a deposit of US$200,000 for their seat.

The first flight is currently being planned for 2010.

It was recently reported Virgin Galactic had turned down a US$1 million offer to shoot a sex video in space.

The company declined the offer to film sex scenes while the participants are floating in zero gravity.