In November 1950, the USAF began development of a balloon reconnaissance system
designation-systems.net
designation-systems.net
http://www.svengrahn.pp.se/trackind/luna3/Luna3story.html (V. Efimov, Novosti Kosmonavtiki, August 2000.)
It appears to be a Russian language magazine (and/or website), possibly this:
There was a fair bit of cloak and dagger to recover the device at the time, nice to see the veil pierced a bit to get the history on it.