Virgin Galactic was operating short of safety standards that allow for crew members to survive two separate and unrelated failures, a safety expert has claimed. Considered best-practice within the industry, the system known as 'two failure tolerance' is designed to allow for survival if there are two unrelated problems on an aircraft. But Tommaso Sgobba, the former head of fight safety for the European Space Agency, said Virgin Galactic's SpaceShipTwo had too few  safeguards in place to prevent an accident he believes was 'waiting to happen'. Scroll down for video A large piece of debris is pictured in the California desert after the spacecraft broke up in the sky above
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Expert claims SpaceShipTwo did not meet a 'two failure' safety standard
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Richard Branson's spacecraft disintegrated over California desert last week
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Its co-pilot Michael Alsbury was killed but pilot Peter Siebold survived
In the wake of the disaster, Mr Sgobba has been highly critical of @placeholder's attempt to pioneer private space travel and claims the company worked in secrecy.