By the 1930s visions of spaceplanes were dancing in the heads of certain forward-thinking dreamers. The Silbervogel concept was one such vision, held by the Austrian engineer Eugen Sänger. Rather than starting with vertically launched rockets to be ballistically lobbed into space, as the conventional rocketmen of his day were contemplating, Sänger was interested in designing a real Raketenflugzeug - a rocket-airplane - for flying into space. He may have been the first to appreciate
that a pilot's spaceship must be flown, not thrown, to its destination. In this respect, he was well ahead of his time. In 1933 he published Raketenflugtechnik, often literally mistranslated as Rocket Flight Engineering, but more accurately translated as Rocketplane Engineering.
The Silverbird concept required more weight than simple rocket designs, because of the need for a structurally sound wing root and landing gear. Sänger immediately recognized the weight penalty this imposed, and he set about solving the problems it presented. Launch would be from an auxiliary track rather than from an ordinary airfield. This would allow a separate rocket sled to provide the initial momentum, thereby relieving the vehicle of extra weight. Thereafter, the pilot would fly Silbervogel up through the atmosphere, gaining maximum speed at the edge of space. The idea was then to fly a series of roller-coaster-like "skips" entering and exiting the upper atmosphere on the way to the ultimate destination. The wings would thus provide a much longer range, even if it meant a higher takeoff weight than in the case of a simple ballistic design. It was believed that the craft could reach a point half-way around the world from the launch site and release a load of bombs anywhere in between - hence, the name "antipodal bomber."
Sänger and his future wife, the mathematician Irene Bredt, collaborated on the Silbervogel design during the latter years of World War II, although no flight hardware was ever manufactured. This may have been an unfortunate circumstance for the development of spaceplanes in general, but certainly fortunate for New York City, which would likely have been its first target.
Was this article helpful?