The Soviet Union launches Zond 1.

Zond 1 was a spacecraft of the Soviet Zond program. It was the second Soviet research spacecraft to reach Venus, although communications had failed by that time. It carried a 90-centimetre (35 in) spherical landing capsule, containing experiments for chemical analysis of the atmosphere, gamma-ray measurements of surface rocks, a photometer, temperature and pressure gauges, and a motion/rocking sensor in case it landed in water. An experimental Ion thruster was also carried for evaluation.