The Rusian Soyuz spacecraft is made up of three main parts -- the Orbital, Descent and Instrumentation/Propulsion Modules. To protect the ship's systems from extreme temperature swings in space, all its surfaces exposed to space, except for active elements of sensors, antennas, windows, the docking hardware, thruster nozzles and radiator panels, are blanketed in multilayer vacuum-screen thermal insulation.
The Orbital or habitation module(Russian acronym: BO) carries crucial life-support systems for the crew, including toilet and water supplies. It also provides extra habitation room during the flight and can serve as an airlock for space walks. In most missions, the front end of the habitation section is equipped with docking hardware, allowing the crew to remain.
The Descent Module (SA) is the reentry capsule of the Soyuz spacecraft where the crew sits during launch and landing. The spacecraft controls for all critical flight activities are in this section, with seats facing the controls and displays. It is the only section of the vehicle, which returns to Earth at the end of the mission; and contains two or three personally contoured couches where the cosmonauts recline for ascent, descent and landing.
The Instrumentation/Propulsion Module known by its Russian acronym as PAO, or Priborno-Agregatniy Otsek, is subdivided into three main sections: Intermediate compartment, Instrumentation compartment, PO, and Propulsion compartment, AO. This section is home to the life support systems, batteries, solar panels and steering engines for the spacecraft. It's the instrument module of the Soyuz spacecraft.
During a typical mission to the International Space Station(ISS), the manned Soyuz launches into orbit atop its namesake rocket from the Baikonur Cosmodrome, located in Kazakhstan, a country on Russia’s southern border. The spacecraft is equipped with multiple engines responsible for maneuvers and orientation in orbit. The main engine and two types of multiple attitude-control thrusters are fed from a set of tanks forming a unified system known by the Russian abbreviation KDU. Along with the rest of the capsule, the KDU went through many re-designs in the course of its decades-long service.
During a typical crewed mission, spent stages of the rocket and other components fall into several designated areas in Kazakhstan and in Russia minutes after their separation. Unlike SpaceX Dragon, the stages are not reusable. It can take up to six hours for a Soyuz capsule to catch up with the space station as it orbits Earth.
Docking to the station is automated like with SpaceX Dragon capsule. The docking was the primary capability of the Soyuz spacecraft during both lunar landing program and numerous space station missions that followed. Several types and reincarnations of the docking hardware were tested between 1967 and 1975, before a long-lived design of the "drog-and-cone system" has emerged. Such mechanism involves a rod on the Soyuz spacecraft, which serves as an active spacecraft during the rendezvous, and a receptive cone, installed onboard the space station.
During a return flight to Earth of a Soyuz spacecraft, only the Descent Module lands. The other two modules are ejected. They burn up in Earth's atmosphere.
Just 15 minutes before landing, four parachutes deploy to slow the spacecraft. First, two pilot parachutes open. Then a drogue parachute deploys on the second pilot chute. The drogue parachute is larger and slows the spacecraft’s speed from 230 mps to 80 mps.
Finally, the fourth and main parachute deploys. The main parachute is 40 times larger than the drogue chute. The main chute changes the angle of the Soyuz capsule to decrease the amount of heat around the vehicle as it travels through Earth’s atmosphere. Then the angle changes again so that the capsule is upright. The main chute slows the vehicle to 7.3 mps. But this speed is still too fast for landing.
Soyuz does not have wheels and does not land like an airplane. Seconds before landing, two sets of small engines fire on the bottom of the spacecraft. These engines slow the spacecraft even more to try to keep its landing from being too rough. But it is still a hard landing. It lands somewhere within a selected 40-kilometer area in the grassy plains of Kazakhstan. The return trip on the Soyuz only takes 3 1/2 hours from space station to Kazakhstan!
During a recent mission, Russia launched Soyuz MS-24 spacecraft, carrying Russian cosmonauts Oleg Kononenko and Nikolai Chub and NASA astronauts Loral O'Hara, to the ISS, welcomed by a crew of 7 occupying the orbiting lab.