Los Angeles - The crash by Virgin Galactic's SpaceShipTwo has raised questions about the programme's future, but Virgin chief Richard Branson has vowed to push forward towards the dream of space flight for the paying public.
A pilot died during the test flight crash, scattering debris across the desert.
"Space is hard - but worth it. We will persevere and move forward together," he added in a statement.
Space flights
Television images showed the wreckage of SpaceShipTwo, a test vehicle that flies to the edge of space, amid brush east of Mojave, a few hours' drive northeast of Los Angeles.
The incident is the second disaster involving a US spacecraft this week, after an unmanned Orbital Sciences rocket carrying supplies to the International Space Station exploded after launch on Tuesday.
It is also a huge blow to British tycoon Branson's long-held dream of offering the first passenger space flights, which have been snapped up by Leonardo DiCaprio and other celebrities.
The Virgin chief is due in Mojave later on Saturday, where the California highway patrol confirmed that one pilot had died and another was seriously injured and taken to hospital.
Space port
Stuart Witt, head of the Mojave Air and Space Port, said WhiteKnightTwo released SpaceShipTwo at an altitude of 13 700m after 50 minutes of flight.
Two minutes later, Witt said it became clear as he watched from the space port that something had gone wrong, even though there was nothing obvious visually from the ground.
"If there was a huge explosion, I didn't see it," he said. "From my eyes and my ears, I detected nothing that appeared abnormal."
The national transportation safety board air safety agency said it was sending a team to the site of the crash.
Forecast
The flight - the 35th by SpaceShipTwo, according to Virgin Galactic's Twitter feed - involved the same configuration as previously, although the type of fuel was new, officials said.
More than 500 people have already reserved seats - and paid a deposit on the $250 000 ticket price - for a minutes-long suborbital flight on SpaceShipTwo, which can carry six passengers.
The SpaceShipTwo's first commercial flight - in which Branson and his family have vowed to travel - has been repeatedly delayed, but was tentatively forecast for the first half of 2015, before Friday's crash.
DiCaprio and fellow actors Ashton Kutcher and Demi Moore are among those already reported to have booked their place.