Mr Nelson has conducted extensive interviews with members of the Apollo space programme and combed through NASA archives, newly declassified CIA documents and oral histories.

ECONOMIST: The race to the moon

For conventional companies, archives are an expensive problem: they need curating, maintenance, storage space, and no-one can ever judge what will be significant in the future.

BBC: Radio

The tapes appear to have been sent to the US National Archives, before being returned to Nasa, which stored them at its Goddard Space Flight Center in Maryland.

BBC: NEWS | Science/Nature | Search on for Moon landing film