Sources told The Guardian that Brin's as-yet-unnamed aircraft will cost between $100m and $150m and be the largest flying object in the world (but still smaller than the iconic Hindenberg). While it can't claim a title over its historical predecessor, it's also filled with non-flammable helium, avoiding its superior's tragic fate. While more details haven't been revealed, as it's still under construction in the Navy's old wartime airship hangers in Northern California's Ames airfield, the craft is planned to be 200m long -- which is kind of hard to hide when Brin does decide to take it out for its first test drive.