To transport crews back and forth between Earth and orbit, the Soviet Union developed several generations of the spacecraft called Soyuz.

Launched from the Baikonur Cosmodrome by a three-stage rocket, the Soyuz can carry two or three crewmembers.

The spacecraft consist of three main sections. During launch, docking and landing operations, the crew stays inside the reentry capsule in the middle of the spacecraft, designed to withstand the heat of the reentry into the atmosphere. It is the only returnable element of the Soyuz. For landing, the capsule uses a parachute and solid motors which fire seconds before touchdown to soften the landing.

The forward section of the spacecraft adds habitable space for the crew onboard Soyuz. It also carries rendezvous antennas and an active docking port, which allows the crew to get inside the station through a system of hatches. The forward section also can serve as an airlock for the crew to work outside the spacecraft.

The aft section of Soyuz, known as the instrument-system module, contains the propulsion unit and other auxiliary systems. It also carries solar panels to supply energy to the spacecraft's systems.

The Soyuz spacecraft also became a base for the Progress cargo ship, which delivers fuel and other supplies to the space station. The Progress is capable of automatically docking to the station.

The Progress Spacecraft

The development of Progress allowed for a dramatic increase in the duration of stays onboard space stations.

In its forward cargo section, the Progress spacecraft carries water, food and other payloads for the station's crew. The middle section is completely filled with the propellant tanks. The aft section of the Progress and Soyuz are virtually the same.

Progress' engines traditionally are used to boost Mir's orbit.