Before their first spy satellites were ever launchable, American spies had used eavesdropping balloons. They’d sprayed toxic metal clouds into the sky that reflected Soviet radio signals from far over the horizon. Fewer and fewer government veterans still remembered any of this stuff. Huge bursts of top-secret ingenuity had just plain been forgotten. It had been nailed into wooden crates and lost inside some warehouse, like the Ark of the Covenant in Indiana Jones.