The atmosphere of our planet protects us from ultraviolet radiation and from numerous meteorites approaching the Earth. Most of them burn up completely in the dense layers of the atmosphere, just like space debris falling from orbit. But this circumstance is a whole problem for the space industry, because astronauts need to not only be sent into orbit, but also returned back. But astronauts safely complete their stay on the International Space Station, returning in special capsules that do not burn up in the atmosphere. Today we will look at why this happens.

Spaceships, like extraterrestrial objects, suffer from the destructive effects of the atmosphere. With the aerodynamic resistance of the gas layers of the atmosphere, the surface of any body moving at a significant speed is heated to critical values. Therefore, designers had to put a lot of effort into solving this problem. The technology for protecting space technology from such effects is called ablative protection. It includes a surface layer based on asbestos-containing compounds, which is applied to the outer part aircraft and is partially destroyed, but allows you to keep it intact spacecraft.

The return of astronauts from the ISS to Earth takes place in a special capsule, which is located on the Soyuz spacecraft. After undocking from the ISS, the ship begins to move towards Earth, and at an altitude of about 140 kilometers it breaks up into three parts. The instrumentation and utility compartments of the Soyuz spacecraft completely burn up in the atmosphere, but the descent vehicle with the astronauts has a protective layer and continues to move on. At approximately an altitude of about 8.5 kilometers, a braking parachute is released, which significantly slows down the speed and prepares the device for landing.

If you look at the photographs of the capsules with astronauts after their landing, you can see that they are almost black in color and have traces of burning as a result of flying through the layers of the atmosphere.

When asked why objects, as well as the astronauts themselves, are in weightlessness while in orbit, you can often hear incorrect answers. In reality, there is a force of gravity in space, because it is what holds the planets together.

Without the action of gravity, galaxies could simply fly apart in all directions. In fact, weightlessness occurs due to the presence of movement speed.

Falling “near the Earth”

In reality, astronauts, as well as other objects that are in Earth's orbit, fall. However, this fall does not occur in the usual sense (to the Earth, with orbital speed), but as if around the Earth.

Moreover, their movement must be at least seventeen and a half miles per hour. When accelerating relative to the Earth, gravity here transfers the trajectory of motion, directing it downward, so astronauts during a flight will never be able to overcome the minimum approach to the Earth. And due to the fact that the acceleration of the astronauts is equal to the acceleration of the space station, they are in a state of weightlessness.

One of humanity's greatest assets is international space station, or ISS. Several states united to create it and operate it in orbit: Russia, some European countries, Canada, Japan and the USA. This apparatus shows that much can be achieved if countries constantly cooperate. Everyone on the planet knows about this station and many people ask questions about at what altitude the ISS flies and in what orbit. How many astronauts have been there? Is it true that tourists are allowed there? And this is not all that is interesting to humanity.

Station structure

The ISS consists of fourteen modules, which house laboratories, warehouses, rest rooms, bedrooms, and utility rooms. The station even has a gym with exercise equipment. This entire complex runs on solar panels. They are huge, the size of a stadium.

Facts about the ISS

During its operation, the station aroused a lot of admiration. This apparatus is the greatest achievement of human minds. By its design, purpose and features, it can be called perfection. Of course, maybe in 100 years they will start building spaceships of a different type on Earth, but for now, today, this device is the property of humanity. This is evidenced by the following facts about the ISS:

1. During its existence, about two hundred astronauts visited the ISS. There were also tourists here who simply came to look at the Universe from orbital heights.
2. The station is visible from Earth with the naked eye. This design is the largest among artificial satellites, and can be easily seen from the surface of the planet without any magnifying device. There are maps on which you can see what time and when the device flies over cities. It's easy to find information about your locality: See the flight schedule over the region.
3. To assemble the station and maintain it in working order, the astronauts went into outer space more than 150 times, spending about a thousand hours there.
4. The device is controlled by six astronauts. The life support system ensures the continuous presence of people at the station from the moment it was first launched.
5. The International Space Station is a unique place where a wide variety of laboratory experiments are conducted. Scientists make unique discoveries in the fields of medicine, biology, chemistry and physics, physiology and meteorological observations, as well as in other fields of science.
6. The device uses giant solar panels, the size of which reaches the area of ​​​​the territory of a football field with its end zones. Their weight is almost three hundred thousand kilograms.
7. The batteries are capable of fully ensuring the operation of the station. Their work is carefully monitored.
8. The station has a mini-house equipped with two bathrooms and a gym.
9. The flight is monitored from Earth. Programs consisting of millions of lines of code have been developed for control.

Astronauts

Since December 2017, the ISS crew consists of the following astronomers and cosmonauts:

• Anton Shkaplerov - commander of ISS-55. He visited the station twice - in 2011-2012 and in 2014-2015. During 2 flights he lived at the station for 364 days.
• Skeet Tingle - flight engineer, NASA astronaut. This astronaut has no space flight experience.
• Norishige Kanai - flight engineer, Japanese astronaut.
• Alexander Misurkin. Its first flight was made in 2013, lasting 166 days.
• Macr Vande Hai has no flying experience.
• Joseph Akaba. The first flight was made in 2009 as part of Discovery, and the second flight was carried out in 2012.

Earth from space

There are unique views of Earth from space. This is evidenced by photographs and videos of astronauts and cosmonauts. You can see the work of the station and space landscapes if you watch online broadcasts from the ISS station. However, some cameras are turned off due to technical work.

Or why don't satellites fall? The satellite's orbit is a delicate balance between inertia and gravity. The force of gravity continually pulls the satellite towards the Earth, while the inertia of the satellite tends to keep its motion straight. If there were no gravity, the satellite's inertia would send it directly from Earth's orbit into outer space. However, at each point in the orbit, gravity keeps the satellite tethered.

To achieve a balance between inertia and gravity, the satellite must have a strictly defined speed. If it flies too fast, the inertia overcomes gravity and the satellite leaves orbit. (Calculating the so-called second escape velocity, which allows a satellite to leave Earth orbit, plays an important role in the launch of interplanetary space stations.) If the satellite moves too slowly, gravity will win the fight against inertia and the satellite will fall to Earth. This is exactly what happened in 1979, when the American orbital station Skylab began to decline as a result of the growing resistance of the upper layers of the earth's atmosphere. Caught in the iron grip of gravity, the station soon fell to Earth.

Speed ​​and distance

Because gravity weakens with distance, the speed required to keep the satellite in orbit changes with altitude. Engineers can calculate how fast and how high a satellite should orbit. For example, a geostationary satellite, always located above the same point on the earth's surface, must make one orbit in 24 hours (which corresponds to the time of one revolution of the Earth around its axis) at an altitude of 357 kilometers.

Gravity and inertia

The balancing of a satellite between gravity and inertia can be simulated by rotating a weight on a rope attached to it. The inertia of the load tends to move it away from the center of rotation, while the tension of the rope, acting as gravity, keeps the load in a circular orbit. If the rope is cut, the load will fly away along a straight path perpendicular to the radius of its orbit.

The International Space Station (ISS) is a large-scale and, perhaps, the most complex technical project in its organization in the entire history of mankind. Every day, hundreds of specialists around the world work to ensure that the ISS can fully fulfill its main function - to be a scientific platform for studying the limitless outer space and, of course, our planet.

When you watch the news about the ISS, many questions arise regarding how the space station can generally operate in extreme space conditions, how it flies in orbit and does not fall, how people can live in it without suffering from high temperatures And solar radiation.

Having studied this topic and having collected all the information into a pile, I must admit, instead of answers, I received even more questions.

At what altitude does the ISS fly?

The ISS flies in the thermosphere at an altitude of approximately 400 km from the Earth (for information, the distance from the Earth to the Moon is approximately 370 thousand km). The thermosphere itself is atmospheric layer, which, in fact, is not yet quite space. This layer extends from the Earth to a distance of 80 km to 800 km.

The peculiarity of the thermosphere is that the temperature increases with height and can fluctuate significantly. Above 500 km, the level of solar radiation increases, which can easily damage equipment and negatively affect the health of astronauts. Therefore, the ISS does not rise above 400 km.

This is what the ISS looks like from Earth

What is the temperature outside the ISS?

There is very little information on this topic. Different sources say differently. They say that at a level of 150 km the temperature can reach 220-240°, and at a level of 200 km more than 500°. Above that, the temperature continues to rise and at the level of 500-600 km it supposedly already exceeds 1500°.

According to the cosmonauts themselves, at an altitude of 400 km, at which the ISS flies, the temperature is constantly changing depending on the light and shadow conditions. When the ISS is in the shade, the temperature outside drops to -150°, and if it is in direct sunlight, the temperature rises to +150°. And it’s not even a steam room in a bathhouse anymore! How can astronauts even be in outer space at such temperatures? Is it really a super thermal suit that saves them?

An astronaut's work in outer space at +150°

What is the temperature inside the ISS?

In contrast to the temperature outside, inside the ISS it is possible to maintain a stable temperature suitable for human life - approximately +23°. Moreover, how this is done is completely unclear. If it is, for example, +150° outside, how is it possible to cool the temperature inside the station or vice versa and constantly keep it normal?

How does radiation affect astronauts on the ISS?

At an altitude of 400 km, background radiation is hundreds of times higher than on Earth. Therefore, astronauts on the ISS, when they find themselves on the sunny side, receive radiation levels that are several times higher than the dose received, for example, from a chest x-ray. And in moments powerful flashes in the Sun, station workers can take a dose 50 times higher than normal. How do they manage to work in such conditions? long time, also remains a mystery.

How does space dust and debris affect the ISS?

According to NASA, there are about 500 thousand large debris (parts of spent stages or other parts) in low-Earth orbit spaceships and missiles) and it is still unknown how much such small debris there is. All this “good” rotates around the Earth at a speed of 28 thousand km/h and for some reason is not attracted to the Earth.

In addition, there is cosmic dust - these are all kinds of meteorite fragments or micrometeorites that are constantly attracted by the planet. Moreover, even if a speck of dust weighs only 1 gram, it turns into an armor-piercing projectile capable of making a hole in the station.

They say that if such objects approach the ISS, the astronauts change the course of the station. But small debris or dust cannot be tracked, so it turns out that the ISS is constantly exposed to great danger. How the astronauts cope with this is again unclear. It turns out that every day they greatly risk their lives.

Space debris hole in shuttle Endeavor STS-118 looks like a bullet hole

Why doesn't the ISS fall?

Various sources write that the ISS does not fall due to the weak gravity of the Earth and the station’s escape velocity. That is, rotating around the Earth at a speed of 7.6 km/s (for information, the period of revolution of the ISS around the Earth is only 92 minutes 37 seconds), the ISS seems to constantly miss and does not fall. In addition, the ISS has engines that allow it to constantly adjust the position of the 400-ton colossus.