Spaceflight itself started on 4. October 1957 with Sputnik, a spherical satellite of diameter 58 cm and weight 83.6 kg. Its perigee was 215 km and apogee 939 km. It burned up in the atmosphere about 3 months later, but before then Sputnik 2 was launched carrying Laika the dog.
USSR Space Stations
From April 1971, several Salyut stations were launched. These were 15m long and, and with a maximum diameter of 4m. They had a circular orbit at a height of 350 km.
Mir was a modified form of Salyut, with six docking ports.