Between 1961 and 1984 the Soviet Union launched 18 spacecraft to explore the planet Venus: 16 in the Venera series and two as part of the Vega program which also explored Halley’s comet. Ten probes landed on the surface of Venus (the only spacecraft to have done so to date), while 13 entered the atmosphere of Venus to explore its composition. “Firsts” accomplished by Venera included the first entry to the atmosphere of another planet, first soft landing on another planet, first images returned from a planet’s surface, first sounds recorded on another planet, and first high-resolution radar mapping of a planet’s surface.