Soyuz

Soyuz is a family of spacecraft designed for human spaceflight by the Soviet Union and, after its dissolution, by Russia. Developed by OKB-1 under Sergei Korolev, the name means Union in Russian. Since its first flights in the late 1960s, the Soyuz spacecraft have formed the backbone of Soviet and Russian crewed space operations and have served missions to Salyut, Mir, and the International Space Station.

A Soyuz vehicle consists of three connected modules: a descent (re-entry) module, an orbital module, and a service module. The descent module is the only part that returns to Earth; the orbital module is jettisoned before reentry, and the service module provides propulsion and power during the mission. An on-orbit maneuvering and docking system enables rendezvous with space stations, and a launch escape system protects the crew during ascent. Typical missions carry three crew members.

Development and variants: Work on the Soyuz concept began in the 1960s with the early 7K-OK design, achieving the first crewed flight in 1967. The design evolved to support docking with space stations and long-duration stays on Salyut and Mir. After the Space Shuttle era, Soyuz became the primary means of transporting crews to the International Space Station. The current variant, Soyuz-MS, features upgraded avionics, a more capable docking system, and revised life support, and is launched on the Soyuz-2 rocket family.

Operational history and significance: Soyuz has conducted hundreds of crewed flights and remains the most frequently used crewed spacecraft in operation. It has enabled continuous human presence on Salyut, Mir, and the ISS and serves as a key element of international cooperation in human spaceflight.