The Soviet Exploration of Venus

The Soviet Exploration of Venus: "The Soviet exploration of Venus, from 1961 to 1984, is the largest effort ever undertaken to study another planet. The fundamentals of interplanetary spacecraft design and remote sensing were first realized in these attempts. Successful missions included 3 atmospheric probes, 10 landings, 4 orbiters, 11 flybys or impacts, and 2 balloon probes of the clouds. " - intersting website - the Soviets had more success here than on Mars.