The Soyuz rockets have been launching satellites, supplies and humans to space for almost five decades. This rocket has been functioning since the ’60s, when Serguei Koroliov, the genius that made enormously progress the URSS during the space race, designed it. Since then, it has been suffering small modifications, but without varying its original design.
The Soyuz rockets, which are not reusable, are composed of three stages. The Soyuz launching vehicle, or rocket, is responsible for putting in orbit the capsule of the same name, which is where the crew is in.
Nowadays diverse models of the Soyuz exist. One of them is designed to carry supplies, like water, food or clothes to the International Space Station (ISS). There is another model that allows carrying humans to space.
The most reliable rocket
Maybe one of the proofs that the Soyuz are very reliable is that they have been launching to space since 1967, suffering minimal modifications. This rocket has an exceptional track record in terms of reliability, having flown more than 120 times, without the death of any crew member. There have only been two incidents that have caused the death of the crew members, the last of which was in 1971, with the Soyuz 11.
What is it used for?
Until recently, the only way to transport humans to the ISS was the Soyuz. The latter launched four times per year with the purpose of taking supplies and humans to the station. As the United States hasn’t the capability to take humans in orbit, it had to buy Soyuz seats from the Russians.
However, with the recent apparition of the Crew Dragon capsule, developed by SpaceX, it is very improbable for the United States to buy more seats from the Russians. As it has already demonstrated on diverse occasions, SpaceX’s capsule is capable of supplying the ISS and to takes humans there. Nowadays, the Soyuz fulfils the necessities of the Russian Federal Space Agency and its commercial customers.
Launching and landing
To get their thrust, the Soyuz rockets burn kerosene and liquid oxygen as fuel. The launchings of the Soyuz take place from the Baikonur Cosmodrome, in Kazakhstan. Before the rocket consumes all of the fuel that it has in its three stages, approximately 15 minutes pass. However, the time it takes before docking to the ISS is of about six hours.
The crew members use the hatchway of the Soyuz to enter and get out of the station.
Once the crew is prepared to return to Earth, they do it in the descent module of the Soyuz capsule. The capsule uses the atmosphere to reduce considerably its initial speed, and, as it approaches the surface, different resources are used to slow it down even more. After using the atmosphere to brake, the Soyuz capsule unfolds two parachutes of small dimensions, which slow down the capsule to a speed of about 80 metres per second.
At this point, the main parachuted opens, with a surface of about 1,000 m2. This allows the capsule to enter a stable descent with a speed of between 6 or 7 metres per second (25 kilometres per hour). If all goes as planned, then the capsule effectuates a series of pre-landing operations, which include the ejection of the thermal shield, which leave in sight six motors using solid fuel.
At an altitude of between 1.1 and 0.8 metres from the surface, these motors come into effect. This slows the capsule to a speed between 0 and 3 metres per second. It is important to note that the Soyuz land on solid ground, and not on the sea like the other capsules.
The Soyuz capsule
The Soyuz capsule, impulsed by the rocket of the same name, is divided in three parts:
- The Orbital Module, which offers additional space to the crew while the latter is in orbit, waiting to dock to the ISS. It has the approximative size of a large van.
- The Descent Module is the place where is the crew during the launch and re-entry to the Earth. It is the only part of the capsule that returns to the Earth.
- The Instrumentation Module is where are find the propulsion systems, the fuel, the batteries, the solar panels which are unfolded once in orbit, etc. Moreover, this module is where the life support systems are found.
The Soyuz has the capacity to carry three persons to orbit, and it has sufficient life support and supplies for a person, for 30 days (or 10 days for a crew of three), During the launch, the capsule is, with the solar panels folded in, at the top part of the rocket, inside the fairing, which serves to protect the useful cargo from the friction with the atmosphere.
Not all launches are successful
As I have explained, the few missions that have failed with this rocket make it very reliable. It has carried humans to space on a great number of occasions, the majority to the space stations that have existed throughout history, such as the Salyut and Mir (Russian stations), and later to the ISS (an international project. As a precautionary measure, there is always a Soyuz capsule docked to the ISS, in the case the astronauts had to leave urgently.
While the majority of launches have been successful, there have been some of them that ended in failures. The majority of these incidents were produced in the launching of satellites and supplies to the ISS. In the majority of cases, there weren’t deaths or injured persons. However, in the history of the Soyuz there have been failures that were much more remarkable:
One of them took place with the Soyuz 1, which finished with the life of its unique crew member: Vladimir Komarov. This incident was produced when, at the moment of the re-entry to the Earth, the system of landing stabilization failed.
The second and last flight in which the crew of the Soyuz died, was the one of the Soyuz 11. At the moment of re-entry, the spacecraft suffered a depressurization, and, as in that epoch the cosmonauts didn’t wear the spacesuits during the launch, and neither during the re-entry, the three crew members died asphyxiated.