American military chiefs allegedly devised the secret project, named 'A Study of Lunar Research Flights' – or 'Project A119' – in the hope that the Soviet Union would be intimidated by viewing the nuclear flash from Earth.

It would give the US a much needed morale boost after the Russians successfully launched Sputnik in 1957, according to physicist Leonard Reiffel, who was involved in the project.

According to the report in The Sun, the US would have used an atom bomb, because a hydrogen bomb would have been too heavy. The planning reportedly included calculations by astronomer Carl Sagan, who was then a young graduate.