Are you nostalgic for a time when the word "zeppelin" stood for leisurely intercontinental travel for the rich and famous, rather than bass-heavy portable sound and MotoBlur phones? Take heart, as Ukrainian entrepreneur Igor Pasternak claims to have solved the "buoyancy problem" that has long limited the usefulness of airships. The problem is that burning fuel or dropping cargo lightens the ship, which then needs to vent costly helium to return to earth; without a way to control buoyancy, take-offs and landings become complicated to the point of useless
