German scientists had seriously planned to build a "sun gun,"

Turns out those flying saucers weren't the only sci-fi weapons the Nazis were hoping would help them take over the world. German scientists were also planning to launch a giant orbiting mirror that could have used the sun's rays to wage war.

According to an article in the July 23, 1945, issue of LIFE magazine:

In Germany last month, U.S. Army technical experts came up with the astonishing fact that German scientists had seriously planned to build a "sun gun," a big mirror in space which would focus the sun's rays to a scorching point at the earth's surface. The Germans, the Army reported, hoped to use such a mirror to burn an enemy city to ashes or to boil part of an ocean. ...

Plausible schemes to build a station in space were engineered on paper long before the war. European rocket enthusiasts, including Dr. Hermann Oberth, who may have been the designer of the V-2, had planned to use the space station not as a weapon but as a refueling point for rockets starting off on journeys into space. ... The only major obstacle: constructing a rocket powerful enough to reach a point where a space station could be built. If the modern German scientists had been able to make such a rocket, they might have ben able to set up their sun gun. Whether the sun gun would have accomplished what they expected, however, is another matter."


[link to blastr.com]