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The satellite was described by the National Reconnaissance Office as ‘the largest in the world’. It is believed it will help the U.S.’s eavesdropping abilities. The un-manned Delta 4-Heavy rocket lifted off from Cape Canaveral Air Force Station in Florida at 5:58pm (2258 GMT).
‘This mission helps to ensure that vital NRO resources will continue to bolster our national defence,’ said Air Force Brigadier General Ed Wilson after take-off. The mission is classified and no other details are accessible.
The rocket is 235ft tall and can launch payloads of up to 24 tons into low Earth orbit.
The Delta 4-Heavy is America’s most powerful liquid-fuelled rocket and generated 2,000,000lb of thrust at take-off. It has been in use since 2004.