During the height of the #Cold_War, the Americans spent 21 years trying to listen in to a secret Soviet radio link used for interplanetary spacecraft. They only succeeded after nabbing a piece of equipment developed by #SETI.
▻http://astronomy.com/bonus/secret #URSS #USSR #NSA #radio #space
"Although the reports are heavily redacted, the story of this quest for the secret Soviet signal is nonetheless astonishing for two interconnected reasons. First, for the sheer depth of effort the Americans spent to uncover the radio signal. And second, for how inconsequential the signal, and the data it hid, actually was"