Virgin Galactic, the space venture of Sir Richard Branson’s Virgin Group, hopes to start testing another spaceship before the end of the year, the company’s chief executive has said in one of his few public comments since a fatal crash last year.

George Whitesides said the spacecraft would be better because of the lessons learnt from the crash, which occurred when a test pilot unlocked a mechanism meant to slow a descending craft while it was climbing.

However, Mr Whitesides, speaking at the annual Space Symposium in Colorado Springs, gave no details about the findings of an investigation by the National Transportation Safety Board. The crash, on October 31, killed Michael Alsbury, the flight’s co-pilot, and seriously injured Peter Siebold, the pilot.