Dave Mackay, the company’s chief pilot, had been flying the mothership called White Knight Two, which had carried the craft into the air before releasing it.
Speaking to the BBC about last October’s disaster over the Mojave dessert in California, he explained that it quickly became apparent that something had gone wrong.
Mr Mackay said: “We were listening out on the radio and it became apparent fairly early that something had gone seriously wrong.”
“We didn’t see anything. We launch the spaceship and it drops below us several hundred feet before it ignites the rocket motor,” he continued.
“When it was apparent the wreckage had hit the ground, we descended to try to give some support in any way we could. Which involved, basically, finding out where the vehicle was and finding out where the survivor was and relaying that position back to emergency services.”
Peter Siebold, 43, the director of flight operations at Scaled Composites, was piloting SpaceShipTwo and survived the crash, but his co-pilot Michael Alsbury was killed when the craft suffered what the firm called a “serious anomaly”.
Mr Siebold had been unaware that Mr Alsbury had earlier unlocked the feathering system that controls descent, the US National Transportation Safety Board (NTSB) said.
Giving an update of its investigation in the weeks following the crash, the NTSB said it had spoken to Mr Siebold.
It went on: “According to the pilot, he was unaware that the feather system had been unlocked early by the co-pilot.
“His description of the vehicle motion was consistent with other data sources in the investigation.
“He stated that he was extracted from the vehicle as a result of the break-up sequence and unbuckled from his seat at some point before the parachute deployed automatically.”
Recalling the fateful day, Mr Mackay expressed his pride at how everyone had reacted, adding that it had taken him some time to get over the “shock and sadness”.
When asked about the future, he recalled German aviation pioneer Otto Lilienthal’s glider fatal crash in 1896, questioning where we would be today if people had given up on flying then.
“It is hard. It has turned out to be harder than we thought it would. But if it was easy, it would have been done a long time ago.”
Speaking last October to the broadcaster, Mr Mackay added that he was enjoying the challenge.
The NTSB’s report into its investigation is due in the next few weeks.
Hundreds of people have signed up for Richard Branson’s Virgin Galactic experience which will take tourists into space.
Virgin Galactic is building a replacement spaceship and says test flights could resume later this year.