Russian crewed capsules
Russia, or the Soviet Union, was the nation to first bring a human to orbit and safely back. Later the capsules became the first to dock to a space station. Russia has had three crewed capsules in it's passed: Vostok, Voskhod and Soyuz. Other crewed platforms such as TKS and Buran have been developed but never flew with a crew. Some of the uncrewed versions of the Vostok and Voskhod capsules are still flying today in the form of the Bion-M capsule.
Vostok
Operator: Roscosmos, Soviet space program
Mission: Bring cosmonauts to LEO
First flight: 1960
Status: Retired (last flight 1963)
The Vostok capsule was the first crewed Russian capsule. The first flight in 1960 with Yuri Gagarin flew for under two hours and completed a single orbit. The Vostok capsules had a 2.4m spherically shaped re-entry capsule which did not generate lift during atmospheric re-entry thus following a ballistic entry. The capsule was covered in thermal protection to protect the cosmonaut regardless of the vehicle's attitude.
After atmospheric entry, the capsule would deploy the single main parachute. Noticeably the Vostok capsules had an ejection seat which shot the cosmonaut out of the capsule before landing.
An unusual feature of the Vostok capsule is the low orbital altitude. The capsule was injected in such an orbit that it would decay in 10 days in case the retrorocket pack failed. This contributed to the safety of the cosmonaut.
Gagarin's Vostok capsule after landing
Voskhod
Operator: Roscosmos, Soviet space program
Mission: Bring cosmonauts to LEO
First flight: 1964
Status: Retired (last flight 1965)
Voskhod was the follow up to Vostok. The capsule was identical in terms of re-entry vehicle, a spherical 2.3 m vehicle, but unlike Vostok, it carried three or two cosmonauts. To make room for the additional cosmonauts the ejection seats were removed. To ensure a safe landing a solid retrorocket pack was included. These solid rocket motors were attached to the parachute system. The capsule only flew twice before being replaced with Soyuz.
Soyuz
Operator: Roscosmos, Soviet space program
Mission: Bring cosmonauts to LEO
First flight: 1966
Status: Active
The Russian Soyuz capsule might be one of the best known crewed spacecraft. The capsule had its first flight in 1966 and is still operational today. The capsule is capable of lifting three astronauts to the ISS. For a long time, the Soyuz capsule was the only capsule to land on land.
Parachute system
The Soyuz parachute system uses "only" four parachutes. Two to pull out the drogue parachute, one drogue parachute, and a single main parachute. Having a single parachute in a crewed capsule has the obvious disadvantage that, when the parachute does not work, the capsule crashes, and the astronauts are in danger. This was part of the reason why the Soyuz 1 mission ended fatally, killing Cosmonaute Vladimir Komarov. Soyuz does have a smaller backup parachute that can be deployed by the cosmonauts when the main parachute does not deploy.
Landing System
The Soyuz capsule has always been unique in that it lands on land. To ensure safe landing, it uses a retrorocket landing system in combination with a crushable structure. Retrorockets are generally lighter in mass than an airbag system and allow for higher terminal velocities. However, a retrorocket system is an active system. This means that it needs to be actuated at a precise time. For the Soyuz, this means the retrorockets fire only 0.8 meters above the ground.
Soyuz firing the retrorockets just before landing. The size of the Soyuz main parachute can clearly be seen compared to the capsule.
The predecessor of the Soyuz, the Voskhod capsule, used an extendable probe to touch the ground. This however proved to be unreliable. The Soyuz uses the "Kaktus" system which uses gamma radiation to detect the ground. The parachute system is capable of decelerating the Soyuz to below 10 m/s, and the landing system decelerates the capsule to about 2.5 m/s. The capsule is designed for a water landing in case of an emergency.
TKS
Operator: Roscosmos, Soviet space program
Mission: Bring cosmonauts to LEO
First flight: 1964
Status: Retired (Last flight 1965)
The TKS spacecraft was an alternative to the Soyuz capsule. TKS was launched onboard a Proton heavy-lift rocket and consisted of two modules: a crew area and a functional cargo block. The main objective of the spacecraft was to fly to the Russian Almaz space stations for resupply missions. Several missions have flown without a crew as test flights. However, the Almaz program was cancelled before TKS became operational. Parts of the hardware later found their way into the Russian modules of the ISS.
Orel
Operator: Roscosmos
Mission: Bring cosmonauts to LEO and to the moon
First flight: -
Status: Under development
Orel is a Russian capsule that has its roots in the CSTS (Crew Space Transportation System), cooperation between Roscosmos and ESA. CSTS was an answer to the American Orion capsule. Thus Orel is able to fly both to an LEO orbit and to the moon. Orel can be launched onboard the Angara and Irtysh launch vehicles. Information on the Orel EDL system is not widely available. Although there are rumours, the capsule might only use propulsive deceleration for landing. The requirement for the landing system is to ensure a landing accuracy of fewer than 10 km. A recent news update showed that Orel will have three main parachutes of 1200 m2 each. The parachute system has redundancy and can operate with one parachute out.
