Sir Richard Branson has said he will persevere with his space tourism venture following the death of a pilot killed when a rocket crashed during a test flight in California.
Describing the tragedy, in which another pilot was seriously injured, as "a devastating loss", the billionaire businessman said he and his team at Virgin Galactic are doing everything they can to support the pilots' families.
Virgin Galactic's SpaceShipTwo rocket came down in the Mojave Desert in California, having "suffered a serious anomaly" after a test flight conducted by partner business Scaled Composites.
Sir Richard, who is expected to arrive in Mojave today, said the journey to the spaceport was "one of the most difficult trips I have ever had to make".
Writing on his website he said: "We've always known that the road to space is extremely difficult - and that every new transportation system has to deal with bad days early in their history.
"Space is hard - but worth it. We will persevere and move forward together."
Many space industry experts and potential passengers have said that will not deter them. Former NASA top space scientist Alan Stern has seats to fly on Virgin Galactic — and its competitor XCOR aerospace. He isn't rethinking plans to fly in space at all.
"Let's not be Chicken Littles here," said Stern, now a vice president at Southwest Research Institute. "The birth of aviation was also a very dangerous time period."
"All forms of transportation carry risk," he said. "To expect spaceflight could somehow be different is unrealistic on the part of the public or anyone. Secondly to do something very hard, to do something on the frontier, comes with risk."
Former NASA astronaut Jerry Linenger, who nearly died in a 1997 fire aboard the Russian space station Mir, said that when he first met British billionaire Richard Branson, founder of Virgin Galactic, he told him the first thing he'd have to worry about is liability insurance. "You will have setbacks," Linenger said he told Branson. "That is a reality."
Wilson da Silva, a journalist, will be among the first 100 people to fly once Virgin Galactic begins its commercial flights. While devastated for the pilots and their families, da Silva is still excited about the prospect of going into space.
"While some have in the past grumbled good-naturedly about the years of waiting, we all know Virgin Galactic is doing something new and very difficult, and any delays have been for sound technical and safety reasons," da Silva said. "This is a reminder that what's being attempted here is pioneering and risky."
Ken Baxter, 65, of Las Vegas, said he was one of those who signed up to make the first flight early next year. He said he was confident the flight will happen at some point. "No question about it," he said. "Richard's not a giver-upper and neither am I."
SpaceShipTwo has been under development at Mojave Air and Spaceport.
It was designed to be carried into the air by the WhiteKnightTwo jet and then released before igniting its rocket to travel into space, and then returning to Earth as a glider.
The flight had taken off at 9.30am local time (4.30pm GMT yesterday) and the two craft had separated at 10.10am (5.10pm GMT yesterday).
On his journey to California Sir Richard said: "Mojave is also where I want to be - with the dedicated and hard-working people who are now in shock at this devastating loss.
"Everyone at Virgin Galactic, The Spaceship Company and Scaled Composites is deeply saddened by today's events. All our thoughts are with the families of everyone affected by this tragic event, and we are doing everything we can to support them."
He added that he and his team will co-operate fully with authorities in their investigation into the crash.
In New Mexico, from where Virgin Galactic planned to launch its flights within the next year, hearts were sinking. The New Mexico Spaceport Authority issued a statement saying its thoughts and prayers were with the crew's family members and the team that has been working for years to develop the rocket.
"We will continue to work with and lend our support to Virgin Galactic through this tragedy and in the coming months as we move forward," the authority said.
The National Space Society said it stands by Virgin Galactic CEO George Whitesides and encouraged the company to press on.
"We expect that the cause of the accident will be found and fixed so that the Virgin Galactic dream of 'opening space to tens of thousands of people' can become a reality," said Mark Hopkins, chairman of the NSS Executive Committee.
At a press conference in California, Virgin Galactic chief executive George Whitesides said: "The future rests in many ways on hard days like this but we believe we owe it to the folks who were flying these vehicles as well as the folks who have been working so hard on them to understand this and to move forward."
He said it was the first time the rocket had been flown using a new fuel formulation.
"It had been proven and tested on the ground many times," he added.
Mr Whitesides said the pilots were employed by Scaled Composites. He added that the injured pilot was "as well as could be expected".
A problem was discovered two minutes after the flight took off, and teams were sent to the crash site 25 miles north of the local airport.
Local Sheriff Donny Youngblood said the rocket was in several pieces on the ground, adding that there was "one person who was obviously deceased immediately".
The other, who had been taken to hospital, appeared to have "major injuries".
A Virgin Galactic spokesman said yesterday: "Virgin Galactic's partner Scaled Composites conducted a powered test flight of SpaceShipTwo earlier today.
"During the test, the vehicle suffered a serious anomaly resulting in the loss of SpaceShipTwo. WhiteKnightTwo landed safely.
"Our first concern is the status of the pilots."
Former Nasa astronaut Leroy Chiao told CNN: "This is a serious setback. I want to stress in this case this was a development programme of a new spacecraft and in the history of developing high-performance aircraft and spacecraft the risks are higher than operational vehicles so mishaps like this do occur.
"As for the impact on commercial space, we will get through this."
Former astronaut Scott Parazynski said he felt sure that the Virgin Galactic programme would recover from the tragedy.
He told Sky News: "They will look at all the data and find out what happened. SS2 was an extraordinary craft. It was not just an evolutionary thing but a revolutionary one.
"I am certain Virgin Galactic will persevere and get to the bottom of what's gone wrong. This kind of venture is very, very challenging and accidents can happen."
Virgin Galactic has been the frontrunner in the race to send paying customers into space and Sir Richard said last month that he hoped to travel with his son on the first flight next spring.
Seats have been sold for over £150,000 with full payment due at the time of booking. The company says customers have visited Sir Richard's Caribbean home, Necker Island, and experienced G-force training.
Physicist Stephen Hawking, singer Justin Bieber, comedian Russell Brand and actor Ashton Kutcher are among the celebrities who have already signed up for flights. Virgin Galactic said it has taken deposits worth more than £50 million from about 700 people.
Yesterday's flight was the 55th for SpaceShipTwo, which was 60ft and featured two large windows so up to six passengers could enjoy the view of Earth below them.
The crash comes days after Orbital Sciences' unmanned Antares rocket exploded moments after lift-off from Wallops Island on the Virginia coast.Suggest a correction