Juno QSL cards have been sent out to those radio amateurs who participated in the Juno Earth flyby experiment.
Amateur radio operators sent a very slow CW (1/25 WPM) to NASA’s Juno spacecraft during its Earth flyby on October 9, 2013.
Hams sent “HI” every 10 minutes as Juno approached Earth, and the message was clearly detected several times. The Juno team confirmed that more than 1400 radio hams participated, representing all seven continents.
Data video: http://youtu.be/Vg80vaGj2Gg
Data video & image caption: http://photojournal.jpl.nasa.gov/catalog/PIA17744
Mini documentary: http://youtu.be/hg9xY1zvrsw
Archived event page: http://missionjuno.swri.edu/hijuno
Radio hams say Hi to Juno https://amsat-uk.org/2013/10/09/radio-hams-say-hi-to-juno/