Paris Hilton 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 $200 000 for their seat.

The first flight is currently being planned for 2010.

It was recently reported Virgin Galactic had turned down a $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.