In 1945, in the final days of the war in Europe, the German rocket engineer Wernher von Braun was interrogated by US and British intelligence officers about the rocket programme he had overseen. Out of it had come the V2 ballistic missiles the Nazis had used to bomb London and Antwerp. The Americans wanted to know how he and his technical team had made this extraordinary weapon, and how he imagined its future development.

The longer arc of the story is one of the most extraordinary of the 20th century: despite his past as a high-ranking SS officer, and his implication in war crimes, he went on to become a beloved American celebrity and the architect of the Apollo moon landings. But in those days after his surrender, as the second World War gave way to the cold war, he wrote a report at the request of his captors – whom he understood would, if he played his cards right, become his benefactors – about the future prospects of the technology he had pioneered.

At the end of his report, after several more or less sober pages on the development of German rocketry, he let his imagination run wild for the benefit of his military-intelligence readers. Intercontinental missiles, interplanetary travel, wheel-shaped space stations: a whole panoply of speculative technologies is sketched in these pages.

One of the stranger ideas von Braun outlined was a gigantic mirror orbiting the planet, which could be controlled so as to concentrate the sun’s heat and light on selected points of the Earth’s surface, enabling cities to receive full sunlight during the hours of night. Such mirrors, he wrote, could even be used to influence the weather itself, by means of systematic concentration of the sun’s rays on certain regions. Given a large enough mirror, it would even be possible to generate lethal degrees........

© The Irish Times