Ascent into space is difficult and dangerous. But this is still half the battle. No less difficult and dangerous to return to Earth. To make the landing soft and safe, astronauts must land on the descent vehicle at a speed not exceeding 2 m / s. Only in this way can we say that neither the astronauts, nor the equipment will feel a hard blow.
Atmospheric reaction
The entry of an aircraft into the atmosphere is accompanied by such phenomena that you cannot imitate when preparing cosmonauts for flight. About how the astronauts return to Earth, many science fiction films have been shot. It all starts at about 100 km. Further from the heating of the atmosphere, thermal protection burns. The descent speed of the apparatus is 8 km / s. The passage through the plasma begins.
Most likely, even the brightest colors will not be able to describe how the astronauts return to Earth, and what they feel at that moment. Behind the porthole, a light show unfolds. First, an unusually bright, pink glow is formed. Then plasma flares up. At this moment, a fire begins to burn and various kinds of lighting effects are observed. It is like a bonfire glowing around an aircraft.
Feelings of pilots
What can you compare with how the astronauts return to Earth? What does it look like? Sitting in the trigger capsule, they are like in the core of a meteorite, from which the flame emanates incredible power. Plasma flares up suddenly. Astronauts observe sparks past the portholes, the dimensions of which are like a good male fist. The fiery performance lasts up to 4 minutes.
Among the science fiction films showing how the astronauts return to Earth, the most realistic is Apollo 13. When flying through the plasma, astronauts hear a strong roar inside the capsule. The frontal protection of the device begins to break due to a temperature of 2 thousand degrees. At such moments, the astronauts involuntarily think about a possible disaster. I recall the shuttle Columbia and its tragedy in 2003, which occurred precisely because of the burning of the hull during the descent.
Braking
After the plasma is left behind, the descent vehicle begins to twist on the parachute lines. He talks in all directions at 360 °. And only after flying clouds, the astronauts see the helicopters meeting them in the windows.
K. Tsiolkovsky worked on issues of braking a descent aircraft. He decided to use the braking of the ship on the air shell of the Earth. When the ship moves at a speed of 8 km / s, the first stage of braking for a short time is activated. Its speed decreases to 0.2 km / s. The descent begins.
Past and present
NASA astronauts used to fly shuttles. Having developed their resource, these shuttles found their place in museums. Today, astronauts fly to the ISS. Before starting the descent, the Soyuz spacecraft are divided into three parts: a module with astronauts for launching, an instrument-and-assembly compartment, and a household compartment. In dense layers of the atmosphere, the ship burns out. Debris that has not burned will fall.
Astronauts experience severe overloads when landing on Earth, in addition, they risk overheating of the spacecraft, because the surface temperature reaches 300 ° Celsius. The material begins to evaporate slowly, and in the windows the pilots see the raging sea of fire.
Then there is a release of the braking parachute using the squib. The second parachute is larger than the first. It is necessary to soften the fit. They also use a soft landing propulsion system that creates a traction control.
Today, astronaut landing systems are more reliable than in the recent past. Thanks to modern automated developments, systems are checked and debugged. The descent is becoming easier. Reusable spaceships resembling huge airplanes have been developed. They land using their engines on special landing strips.