William Shatner refused to go on Sir Richard Branson's space flight because he's scared of flying.
The 82-year-old actor - who played Captain James T. Kirk in the original 1960s TV series of 'Star Trek' - turned down the chance to join the British business tycoon's Virgin Galactic programme because he couldn't handle the fear of being up in the air.
Sir Richard is quoted by The Sun newspaper as saying: "He actually said he's frightened of airline travel -- which is slightly disillusioning. Captain Kirk is scared of flying."
The star was invited to take part in the space mission in 2011, but claims he was less than impressed when faced with the bill.
He explained: "He wanted me to go up and pay for it and I said, 'Hey, you pay me and I'll go. I'll risk my life for a large sum of money'. But he didn't pick me up on my offer."
The 63-year-old investor has just added British rock band Muse to the list of star-gazing celebrities joining him on the flight, but he insists regardless of how famous they are, they'll have to pay their own fares, which costs $200,000 per seat.
He said: "We have a policy that, however famous people are, they won't get upgrades or freebies.
"I think Muse can afford to pay their way. We'd love them to go into space and play."
Other confirmed famous passengers include 'Two and a Half Men' star Ashton Kutcher, Mila Kunis, Justin Bieber, Leonardo DiCaprio and Russell Brand.
The first ever two-hour flight in the planet's orbit will be boarded by Branson and his family and anyone who has paid a deposit guaranteeing them a place on it.
Passengers will travel 62 miles in altitude - the internationally recognised boundary of outer space - and will experience weightlessness and an incredible view of the curve of the Earth.