Silbervogel, German for Silverbird, was a design for a rocket-powered sub-orbital bomber aircraft produced by Eugen Sänger and Irene Bredt in the late 1930s. It is sometimes referred to as the Amerika Bomber, although it was only one of a number of designs considered for this mission. When Walter Dornberger attempted to create interest in military spaceplanes in the United States after World War II, he chose the more diplomatic term antipodal bomber. The design was a significant one, as it incorporated new rocket technology, and the principle of the lifting body. In the end, it was considered too complex and expensive to produce. The design never went beyond wind tunnel testing.
The Silverbird was intended to fly long distances in a series of short hops. The aircraft was to have begun its mission propelled along a 3 km (2 mile) long rail track by a large rocket-powered sled. Once airborne, it was to fire its own rocket engine and continue to climb to an altitude of 145 km (90 miles), at which point it would be travelling at some 22,100 km/h (13,800 mph). It would then gradually descend into the stratosphere, where the increasing air density would generate lift against the flat underside of the aircraft, eventually causing it to "bounce" and gain altitude again, where this pattern would be repeated. Because of drag, each bounce would be shallower than the preceding one, but it was still calculated that the Silbervogel would be able to cross the Atlantic, deliver an 4,000 kg (8,800 lb) bomb to the continental US, and then continue its flight to a landing site somewhere in the Japanese held Pacific, a total journey of 24,000 km (15,000 miles).