Zond 3MV 1 No.2

Zond 3MV-1 No.2 (or No. 4A ), also known as Venera 1964A in the West, was a Soviet spacecraft, which was launched in 1964 as part of the Zond program. Due to a problem with its carrier rocket third stage, it failed to reach low Earth orbit.

Zond 3MV-1 No.2 was launched at 05:47:40 UTC on 19 February 1964, atop a Molniya 8K78M carrier rocket flying from Site 1/5 at the Baikonur Cosmodrome. During ascent, LOX entered an RP-1 duct due to a leaking valve and formed a glob of explosive gel, so when core separation and Blok I ignition began, the thrust section exploded. The remains of the stage and probe landed 52 miles (85 kilometers) north of the town of Barabinsk in Siberia.