On its maiden voyage in 1628, the most powerful warship in the Baltic, the Vasa, was afloat only minutes before capsizing in front of stunned onlookers in the city's harbor. Hundreds of years ...

Since then, the ship, which is largely intact, has been exhibited at the popular Vasa Museum. But preserving the wreck is complex: the wood has shrunk over the years and the hull is sagging due to ...