Caspian Sea Monster. Not a plane, not a ship

In the 1960s, an American satellite flying over the USSR captured something that had left many within the US intelligence community scratching their heads. A gigantic machine that didn’t look like anything they’d seen before: not a plane, not a ship but something else. Confused by the type and purpose the Americans dubbed their discovery the Caspian Monster or the Caspian Sea monster which is how it's generally known today.