London: Adolf Hitler had a bizarre plan of sending manned rockets into space to attack America, newly discovered papers have revealed.
The head of the Luftwaffe Hermann Goering needed a dynamic new scheme to catch the Fuehrer's eye. In the warped world of the Third Reich, competition between the German army and the German air force - the Luftwaffe - was fierce.
Under Hitler's power-crazed dictatorial leadership senior Nazis vied and tussled for influence throughout the Second World War, the Daily Express reported.
At the end of 1941, Goering's Luftwaffe was on the back foot. It had lost the Battle of Britain, while the German army was rampaging triumphantly across Russia.
The United States had just joined the war following the attack on Pearl Harbor and the Fuehrer was keen to build a long-range bomber that could attack America's eastern seaboard.
By successfully attacking the US, Goering could consolidate his position within the Third Reich.
But the Luftwaffe relied on slow, piston-powered aircraft with limited range - and a round trip from Berlin to New York was more than 7,000 miles. The US was simply too far away. A major technological innovation was required and Goering sent his technical staff scurrying away to find solutions.
A few years earlier, a maverick Austrian engineer named Eugen Saenger had published a paper proposing a manned, rocket-propelled space-plane that could in theory fl y anywhere in the world.
How much Goering actually understood of Saenger's ideas is unclear but he was hired and put to work at a laboratory near Hamburg with a small support team - including physicist Irene Bredt, who would become his wife - and told to come up with a blueprint for an inter-continental bomber.
The 900-page plan that Saenger eventually submitted to the Air Ministry could have flown straight out of the pages of Flash Gordon.
In order to bridge the Atlantic he proposed sending a manned, rocket-powered jet into the lower reaches of space. The sub-orbital bomber was to be named the Silverbird because of its metallic appearance.
The Silverbird was to be launched on a huge sled attached to a twomile monorail powered by 36 V-2 rocket engines. This awesome, fiery blast would propel the craft forward at a coma- inducing 1,200 miles per hour. At the end of the rail, the space-plane would start climbing.
30 seconds after liftoff the craft's own 100-tonne thrust motor would kick in.
Eight minutes after ignition the Silverbird would have reached an altitude of more than 80 miles above Earth - the commonly accepted boundary between Earth and space is 62 miles above sea level - allowing it to in theory skip across the atmosphere like a stone bouncing over a pond.
If the space-plane concept wasn't far out enough, the bomb it was carrying was out of this world.
According to aviation historian David Myhra, the plan was to wrap the bomb with radioactive sand and have it explode high above New York casting a radioactive cloud over the city.
The Silverbird would have been travelling at a jaw-rattling 13,000 miles per hour.
Once it had dropped its payload, the Silverbird would descend under the pull of gravity, re-enter the atmosphere and glide back to Japanese territory in the Pacific.
By spring 1942 the rotund art-lover had a lot on his plate. The war in Europe was not going well and he was under intense pressure to stop Allied bombing raids on German cities.
According to space historian Dr David Baker, Goering saw the Silverbird as an implausible scheme with too many uncertainties.
Myhra adds that post-war analysis indicated that the space-plane would have burnt up during re-entry but this could have been overcome with thermal shielding. The underlying concept was sound but it was many years ahead of its time.
The Nazis would look to other schemes to bomb the US but never succeeded. Saenger carried on tinkering with his concept and an abridged, 125-page outline was submitted to the Air Ministry in 1944 as the conflict entered its final stages. A copy of this top-secret document would fall into the hands of the Americans and the Russians who were advancing on Berlin.
At the end of the war in 1945 Saenger fled to France but his bizarre story doesn't end there. By this stage, Soviet dictator Josef Stalin had taken an interest in the Silverbird. The Cold War was just beginning.
Stalin ordered his agents to kidnap the Austrian and bring him to work in the Soviet Union. But the bungling agents failed to locate him and he stayed safely in the West.
The Soviets would spend a lot of resources trying to build a copy of the bomber. But by the early Fifties, Russian engineers gave up, concluding that the technology required to build it was yet to be invented.
In December the US military launched its secretive X-37B unmanned space-plane on its third test flight.
Eugen Saenger died in 1964. He did not live to see the wide-ranging influence his visionary ideas would have on aviation, rocketry and space travel.