U. S. Aeronautics and Space Activities, January 1 to December 31, 1960. (PDF) The White House, 18. Januar 1961, S. 2, abgerufen am 17. August 2017 (englisch): „Communication with the Juno II launch vehicle was lost after second stage burnout. Probable cause of failure: a malfunction in one of the rockets in the second stage cluster causing angle deviation and a decrease in velocity.“
nssdc.gsfc.nasa.gov
S 46A. In: NASA Space Science Data Coordinated Archive. Abgerufen am 17. August 2017 (englisch): „Telemetry was lost shortly after the first stage burnout and one of the upper stages failed to fire. The spacecraft did not achieve orbit.“
