Richard Branson said almost 800 would-be space tourists signed up for $250,000 flights with his Virgin Galactic venture have been understanding about glitches that caused commercial services to be delayed until 2015.

Pushback from clients who include physicist Stephen Hawking, singer Sarah Brightman and X-Men director Bryan Singer has amounted to “almost none whatsoever,” the U.K. billionaire told Bloomberg Television. [Video embedded below] “Everyone’s been very patient. They realize that it’s rocket science. They want to make sure that we don’t hurry them up there, and they want to come back.”

Virgin Galactic won’t now make a commercial flight until early spring, with Branson and his son on the first launch, the U.K. billionaire confirmed today after revealing earlier this month that a target of commencing operations this year had become unrealistic. The resolution of issues with the spacecraft’s rockets may mean a vehicle carrying flight crew but no passengers still reaches space during 2014, he added.

“It took us a lot longer to build rockets that we felt completely comfortable with,” Branson said today. “I’m confident that we’re as good as there now. We’ve got some more test flights to go, but I think you’ll start seeing Virgin going into space by the end of this year and then starting the whole space program in the spring.”

Regulations

In the latest phase of development, the WhiteKnightTwo carrier aircraft was this month deployed to Spaceport America in New Mexico, where commercial flights will be based, to aid familiarization with airspace rules in the El Paso area and practice landings and diversions, as well as simulate launches.

Writing in his book “Branson Behind the Mask,” published on Feb. 6, author Tom Bower said a combination of safety regulations, performance issues and the physical challenges of a rocket launch mean Virgin Galactic is unlikely ever to attain its goal of carrying passengers into sub-orbital flight.

The program has suffered numerous setbacks, with three people working for Virgin partner Scaled Composites — now a unit of Northrop Grumman Corp — killed in an explosion in 2007.

Virgin Galactic — backed by Abu Dhabi-based Aabar Investments PJS — says it’s still on track to become the world’s first commercial spaceline, having accepted more than $80 million in deposits from a clientele that includes some of the world’s highest net-worth individuals.

Testing including blast-offs and rocket-powered supersonic flights has been focused on the Mojave Air and Space Port in California. Under the Virgin plan, the WhiteKnightTwo vehicle will carry a SpaceShipTwo orbiter to almost 50,000 feet, from where the SS2 will climb to 360,000 feet, allowing passengers to experience weightlessness, dark skies and view the curvature of the earth. Flights have reached at least 71,000 feet to date.

Branson says Virgin Galactic’s ultimate ambition is to fly between cities at near-orbital speeds, slashing even the longest journey times such as London-Australia. Closer prospects include launching satellites at a fraction of the cost of current programs, while NASA has used test flights for research.

–With assistance from Rishaad Salamat in London and David Fickling in Sydney.

To contact the reporter on this story: Christopher Jasper in London at [email protected] To contact the editors responsible for this story: Benedikt Kammel at [email protected] 

Photo Credit: Virgin Galactic breaks speed of sound in first rocket-powered flight of SpaceShipTwo. Virgin Galactic