The Soviet Exploration of Venus
From the beginning of the space age, Soviet rocket designs were able to launch substantially larger payloads into space. United States rockets, by comparison, were limited in their lift capabilities.
While the exploration of Mars was well accomplished by the Americans using lightweight spacecraft, the extreme temperatures and pressures discovered on Venus required heavy-duty construction not unlike that seen in deep sea submersibles. At this, the Soviets excelled.
While the United States focused its exploration on the Moon and Mars, they explored Venus.
What it meant for the Space Race
In a sense, this initial success with heavy payloads led to later Soviet failure. Because they were less concerned with the weight of their payloads, they had less incentive to miniaturize components, develop lightweight materials, and to design automated control systems which would remove levers, gears, and heavy flight control apparatus. The United States, in contrast, kept a worried count of pounds and ounces. This lead US technology down a different path of development (microcomputers, plastics and new metal alloys, and fly by wire systems).
When it came time for the race to the moon, the Soviets were primed for failure. Their N-1 rocket, while theoretically capable of lifting the required payload, failed to operate as designed. Engineers were unable to overcome the crushing complexity of its enourmous design (over thirty rocket engines combined at the base to produce thrust).
The Saturn V rocket produced the needed 3,750 tons of thrust to send its American craft to the Moon. By comparison, the Soviet N-1 rocket was designed to provide 7,500 tons of thrust. They needed this unbelievably massive rocket because their payload was 18.5 metric tons heavier (about 25%) than the American version.