But destruction isn't the first choice, of course. Even old warships are valuable vessels. So when the Navy uses the Foster to test new defensive weapons, the warship is trailed 150 feet behind by a barge stacked with shipping crates in an almost crude, LEGO-like simulacra of the Foster's appearance (call it a "Foster Imposter", if you will). While the Navy sends cruise missiles flying at the shipping crates on the barge, the Foster's sensors are fooled into thinking the Foster is the target, so the old warship responds to the perceived threat with its anti-missile defenses. The whole time, the Foster is controlled remotely by sailors elsewhere, ensuring no lives are at risk from a weapon misfire or an accidentally successful hit.