When we talk about the space race between the Cold War adversaries the U.S. and the Soviet Union, we usually discuss the race to land the first human beings on the moon. Soon after this was achieved, however, attention shifted to our neighbouring planet Mars. The first successful soft landing on Mars was achieved by the Soviet Union with their Mars 3 mission.
At this initial period of planetary exploration, both these space superpowers tended to launch pairs of spacecraft as a precautionary measure. The idea was to have one as the backup of another, so that at least one of them succeeded in its efforts even if the other failed completely in its objective.
It therefore comes as no surprise that the Mars 2 and Mars 3 missions consisted of identical spacecraft. With a bus/orbiter module and an attached descent/lander module, the combined mass of the spacecraft, with fuel, was approximately 4,650 kg. The Mars 3 spacecraft was 4.1 metres high, 5.9 metres across the two solar panel wings and had a base diameter of 2 metres.
