The Soviet Union launches the space probe Zond 1 toward Venus, a more sophisticated version of the Venera 1 vehicle sent to that planet in 1961. Thanks to an electrical short within the Zond space probe, ground controllers lose all contact a month after it leaves Earth; by the time it swings past Venus at over 60,000 miles months later, Zond 1 has shut down completely.
theLogBook.com
https://www.theLogBook.com
Earl Green is the creator, curator, and head writer of theLogBook.com.
Also of interest...
Pioneer 11 launched
April 6, 1973
Viking 2 signing off
April 11, 1980
Voyager 1 at Saturn
November 12, 1980