Virgin Galactic chief executive George Whitesides said the crash is a tragedy, but has not changed the company’s commitment to developing space tourism.
“Space is hard and today was a tough day,” he said.
“We are going to be supporting the investigation as we figure out what happened; and we’re going to get through it.
“The future rests on – in many ways – 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.
One pilot was killed and another seriously injured when a Virgin Galactic spaceship crashed in the desert, a spokesman for the California Highway Patrol said.
The injured pilot was taken to hospital, a spokesman said.
The flight took off from the Mojave Air and Space Port, about 150 kilometers north of Los Angeles.
The company said a “serious anomaly” resulted in the crash.
“Our first concern is the status of the pilots, which is unknown at this time. We will work closely with the relevant authorities to determine the cause of the accident and provide updates as soon as we are able to do so,” it said in a statement.
FAA investigates crash
The US Federal Aviation Administration is conducting an investigation into the incident, while the US National Transportation and Safety Board (NTSB) said it is “in the process of collecting information”.
Former senior NTSB investigator Greg Feith told said the NTSB and FAA are likely to treat the investigation in the same way as it would treat a crash involving a commercial airliner.
“They will be looking a rocket fuel. They will be looking at the entire launch sequence. It will be conducted as if the FAA were conducting a major investigation of an aircraft, a commercial airliner,” he told CNBC.
“So there is going to be a lot to be done, but it is too early to even speculate because there is no real solid information at this point.”
Eyewitness reports mid-flight explosion
Photographer Ken Brown, who was covering the test flight, told NBC News that he saw a midflight explosion and later came upon SpaceShipTwo debris scattered across a small area of the desert.
Blogger Doug Messier with space news website Parabolic Arc said he witnessed the crash from a station overlooking the crash site in the Mojave desert.
鈥淲e saw the twin contrails of WhiteKnightTwo overhead. They do that prior to a drop,鈥?he tweeted.
鈥淪paceShipTwo dropped. From what I could tell, motor fired and then stopped then fired again. I think that鈥檚 what happened.鈥?/p>Richard Branson travels to crash site
Part-owner of Virgin Galactic Richard Branson said he is flying to Mojave to be with his Virgin Galactic team in the wake of the crash.
Thoughts with all @virgingalactic & Scaled, thanks for all your messages of support. I’m flying to Mojave immediately to be with the team.
鈥?Richard Branson (@richardbranson) October 31, 2014Concerns over the dangers of space tourism
Former corporate pilot Anthony Roman said the crash underscores the dangers of space tourism.
“The early airlines of the ’20s were a risky endeavour and went down with some regularity; so did the early single engine, single pilot aircraft.
“And it’s a series of technological steps and mishaps; and learning from these mishaps and the sucesses that eventually build to modern and safe technology.”
Retired NASA astronaut Mark Kelly said despite the risks, space tourism will be a reality in the future.
“I know Richard Branson is not doing this so he can bring passengers to an altitude of 68 miles and safely back to the ground.
“You know, ultimately he and others envision the way you would get – let’s say from Los Angeles to London, would not be on an airplane. Somewhere in the future [it] would be on a spaceraft.
“If I was take off in a space shuttle from the Kennedy Space Centre in Florida and land in London, I could do that in about 25 minutes. You know the future is that travel around this planet will be in a spaceraft and not necessarily in an aircraft.”
The test flight was part of Virgin Galactic’s long-running program to prepare the SpaceShipTwo for trips in outer space.
More than 800 people have booked flights aboard the spaceship, which takes people 100 kilometres above the Earth, offering them an experience of a few minutes of weightlessness.
The tickets cost as much as $250,000, with actors Angelina Jolie and Tom Hanks among those who have booked a spot.
The spaceship is based on an award-winning prototype that was recognised a deacde ago as the first privately developed manned spacecraft to fly in space.
The accident is the second this week by Virgin airlines. On Tuesday, a cargo ship bound for the International Space Station exploded 15 seconds after liftoff from Wallops Island, Virginia.