International space station 'greatest engineering project in the history of mankind'

Christopher Shank, head of strategic communications at the National Aeronautics and Space Administration (NASA), says that the International Space Station (ISS) is 'the greatest engineering project in the history of mankind.' Shank says the ISS is larger in wingspan than a football field and that its development is the largest task ever to have been performed by civilian agencies. (0:33)
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