The quiz is why the designers propose to cover the descent compartments. Let's see how spaceships actually return - is2006

With. one
UPK-8, Krasnokamsk

Quiz

1. 
   Why do designers propose to cover the descent compartments of a spacecraft with a layer of fusible material?

The temperature of the ship upon entering the dense layers of the atmosphere reaches several thousand degrees, the ablative protection under such conditions gradually burns out, collapses, and is carried away by the flow, thus removing heat from the body of the device.

Protection technology spaceships, thermal protection based on ablative materials, structurally consists of a power set of elements (asbestos textolite rings) and a "coating" consisting of phenol-formaldehyde resins or similar materials.

Ablative thermal protection was used in the designs of all descent vehicles from the first years of the development of astronautics (series of ships Vostok, Voskhod, Mercury, Gemini, Apollo, TKS), continues to be used in the Soyuz and Shenzhou spacecraft.

An alternative to ablative thermal protection is the use of heat-resistant heat-shielding tiles ("Shuttle", "Buran").

2.Can I use on space station pendulum clocks?

The pendulum works due to gravity, but there is no gravity on the space station, here the state of weightlessness. Pendulum clocks won't work here. The space station will operate a mechanical (spring) clock.

The first watch to fly into space belonged to Yuri Alekseevich Gagarin. These were Soviet "Navigators". Since 1994 official hours training center astronauts swiss steel watch Fortis. In the early 2000s, the ISS tested orbital watch "Cosmonavigator", developed by cosmonaut Vladimir Dzhanibekov. This device allowed at any point in time to determine which point of the Earth are the ship. The first dedicated watch for use in outer space is the Japanese Spring Drive Spacewalk. Electronic watch did not take root in orbit. The spacecraft is pierced by high-energy particles that disable unprotected circuits

Is it possible to drink water from a glass in zero gravity?

Before the first flights into space, it was largely a mystery to scientists how to organize a meal in a state of weightlessness. It was known that the liquid would either gather into a ball or spread over the walls, wetting them. So, it is impossible to drink water from a glass. It was proposed to the astronaut to suck it out of the vessel.

Practice basically confirmed these assumptions, but also made some significant amendments. It turned out to be convenient to eat from tubes, but, being careful, you can eat food in its earthly form. The astronauts took with them fried meat, slices of bread. Four meals a day were organized for the crew on the Voskhod ship. And during the flight of Bykovsky, viewers saw how he ate green onions, drank water from a plastic bottle and ate roach with special pleasure.

We saw on the site http://www.youtube.com/watch?v=OkUIgVzanPM how American astronauts drink coffee. But the glass there is also plastic, its shape can be changed. You can squeeze liquid out of it. This means that it is almost impossible to drink the water from their usual solid glass cup.

Today, each member of the crew of the International Space Station (ISS) has an individual mouthpiece for drinking, which is mounted on the syringes of the branched onboard water supply systems "Rodnik" . The water in the "Spring" system is not simple, but silver-plated. She is passed through special silver filters , which protects the crew from the possibility of a variety of infections.

But perhaps in the near future astronauts will easily be able to drink water from an ordinary glass. Large-scale studies of the behavior of liquids and gases in weightlessness are planned on a platform independent of the ISS. Now go design work in which teachers and students of the department participate general physics Perm University. Research in this direction has been carried out in Perm for more than 30 years.

4. Which of the astronauts was the first to visit outer space?

First out in outer space Soviet cosmonaut Alexei Arkhipovich Leonov on March 18, 1965 from the Voskhod-2 spacecraft using a flexible airlock. 1 hour 35 minutes after the launch (at the beginning of the 2nd orbit), Alexei Leonov was the first in the world to leave the spacecraft, which was announced to the whole world by the spacecraft commander Pavel Belyaev: “Attention! A man has gone into outer space! A man has gone into outer space! " The television image of Alexei Leonov soaring against the background of the Earth was broadcast on all television channels. At this time, he moved away from the ship at a distance of up to 5.35 m. His suit consumed about 30 liters of oxygen per minute with a total supply of 1666 liters, designed for 30 minutes of work in outer space. It was very difficult for him to return to the ship. He speaks about this in an interview from the pages of the General Director magazine (No. 3, 2013): “ Due to the deformation of the suit (it swelled up), the phalanxes of the fingers came out of the gloves, so it was very difficult to wind the halyard. In addition, it became impossible to enter the ship's airlock feet first, as it should be. ... There was no time to panic: there were only five minutes left before entering the shade, and it was impossible to wind the halyard in the shade. ... I kept thinking about what would happen in five minutes, and what would happen in thirty. And acted on the basis of these considerations.

The total time of the first exit was 23 minutes 41 seconds (of which 12 minutes 9 seconds were outside the ship). He conducted medical and biological research, helped in solving problems of space navigation. Based on the results of the exit, a conclusion was made about the possibility of working in open space.

Due to an emergency, the ship landed in the Perm Territory, near the village of Kurganovka, on the border of the Usolsky and Solikamsky regions on March 19, 1965. They were not immediately found in the remote Ural taiga. In memory of this event, the streets of Belyaev, Leonov, and the highway of Cosmonauts appeared in Perm. In three years astronauts have been here again. A stele was erected at the landing site. Alexei Leonov has been a guest of Perm more than once.

The cosmonauts became honorary citizens of Perm. In general, more than a third of the honorary citizens of Perm are connected with the space industry. After all, the road to space begins with us. In March 1958, the government of the USSR decided to expand the production of rockets and rocket engines at Perm enterprises. 19 largest factories and design bureaus worked for space. Rockets equipped with Perm engines launched hundreds of spacecraft. Today in Perm, there are three enterprises that assemble individual components or entire engines of space rockets. Proton-PM manufactures liquid-propellant engines for Proton launch vehicles. NPO Iskra produces solid-propellant rocket engines, and the Perm plant Mashinostroitel manufactures various rocket mechanisms.

Perm universities graduate specialists for the aerospace industry, and also conduct research programs on space topics.

In 2013, a team of scientists from the Department of General Physics, Faculty of Physics, Perm State Research University was again invited to participate in the implementation of the Federal Space Program of Russia. Together with specialists from the Energia Rocket and Space Corporation, physicists from Perm State University will develop scientific equipment and an applied research program for the newest OKA-T spacecraft.
With. one

So, the descent vehicle, descending under the influence of the Earth's gravity, gradually enters the increasingly dense layers of the atmosphere. The lower, the greater the air resistance, the more it slows down the descent vehicle, the lower the speed becomes, the steeper the trajectory of its descent becomes.

However, what does “the slower the speed becomes” mean? This means that it is decreasing kinetic energy apparatus. And we know that energy does not disappear and does not appear - it can only pass from one form to another. In this case, the kinetic energy of the descent vehicle is converted into thermal energy, that is, it is spent on heating the oncoming air and the descent vehicle itself.

How the transfer and transformation of energy takes place, we will not consider here. Now it is important for us that this kinetic energy is huge - the same as that of a heavily loaded railway train rushing at a speed of 100 km / h! And almost all of this huge energy must be converted into thermal energy. If special measures are not taken, then one third of it will be enough to turn the entire descent vehicle into steam.

As a result of deceleration, the front surface of the descent vehicle heats up to a temperature of about 6000°. The air at the front wall of the descent vehicle will have such a temperature. This is no longer the air we are used to, consisting of molecules of nitrogen, oxygen and carbon dioxide, but a plasma consisting of nitrogen, oxygen and carbon atoms, ions and electrons.

Remember the table of melting points various substances. Is there at least one material in it that at this temperature will remain in a solid state? No. All materials known to us at this temperature turn into a liquid or even into a vapor. And even if we had a material that would not melt at such a temperature, this is not enough. After all, the most important thing is that the resulting braking great amount no heat was transferred inside the descent vehicle. Whatever the temperature outside the descent vehicle, in the crew compartment it should be normal, room temperature. To do this, the walls of the descent vehicle must be well protected from heat, that is, have low thermal conductivity. But that's not all. They must be very strong - after all, when braking in dense layers, the descent vehicle is subjected to enormous pressure. In addition, it is necessary that the walls of the ship have as little weight as possible, because on a space ship every gram of weight counts.

So, the material must have a high melting point, and low thermal conductivity, and high strength, and besides, small specific gravity. And although in our time scientists have created and are creating a wide variety of artificial materials, none of them can satisfy all these requirements at the same time.

How to be? When this question arose, scientists and engineers began an intensive search for a way out of the situation. Maybe cover the entire descent vehicle with copper cladding? Copper has very good thermal conductivity, and due to this, heat from the front surface will be removed to the side and rear walls of the descent vehicle (only the front, frontal surface of the ship heats up strongly).
But such a skin will weigh a whole ton, which means that the launch weight of the launch vehicle and, consequently, the thrust of the engine will have to be increased by 50 tons. In addition, in this case, almost all the heat will still remain on the ship and gradually pass into the descent vehicle.

There was a proposal to make the front surface of the device porous (that is, having many tiny holes) and through these pores during the descent to push cold liquid or blow out gas from inside the ship. This idea is actually not bad, but it is difficult to implement it, since at high temperatures and pressures that arise on the front surface of the descent vehicle, the pores will become clogged, melted, etc.

The most effective method was proposed by Soviet scientists. Now this method is used when returning to Earth all descent vehicles - both Soviet and American.

Scientists argued something like this. There are currently no materials that meet all four requirements, and it is unlikely that they will be created in the coming years. There is not even material that would satisfy only the first requirement, that is, would have enough high temperatures melting and evaporation. But after all, the main task is to ensure that the temperature in the crew compartment remains at room temperature, that is, that as little heat as possible passes into the ship. And this can be achieved in the following way.

Let us cover the front wall of the descent vehicle with a material that, although it melts or evaporates at this temperature, requires for its melting and evaporation a large number heat (or, as scientists say, it has large latent heats of phase transitions), and in the molten state it has low viscosity (it flows easily). Then, during the descent, this material will heat up, melt and evaporate, and as soon as it melts, drops and vapors of the material will be blown away from the surface of the descent vehicle by a counter flow of air. In this case, the heat that has accumulated in drops and vapors during heating, melting and evaporation of the material will be carried away from the apparatus along with drops and vapors instead of being transferred from them inside the ship.

To reduce heat transfer into the apparatus, a layer of material with a very low thermal conductivity must be placed under a layer of this material. The strength of the structure can be ensured by making the third layer - a frame made of light titanium alloys, and attaching a “carrying away” shell of a low-heat-conducting material to it. This method is called "thermal protection due to mass entrainment".

It is this method that is currently used on all descent vehicles. Thus, during the descent in the dense layers of the atmosphere, the descent vehicle rushes, surrounded by a veil of hot plasma and drops of heat-shielding material. This veil envelops the ship's antennas, and since the plasma does not transmit radio waves, communication with the Earth is terminated. But it only lasts a few minutes. The air slows down the ship so much that while it descends from 100 kilometers to 30 kilometers, its speed decreases by 56 times! Now it is already possible to produce a stabilizing parachute with a dome diameter of several meters, and at an altitude of 10 kilometers - the main one, with a diameter of several tens of meters. Designers very simply and witty came up with how to do what

the ship would meet the surface of the Earth gently, without any impact (without a push). To do this, a pin about one meter long is produced from the bottom side of the apparatus. When this pin is inserted into the Earth's surface, it automatically turns on the soft-landing solid-propellant thrusters, whose nozzles are directed downwards. As a result, the rest of the speed is extinguished.

Why is such a complex system of descent and landing used? Why not slow down the descent vehicle from beginning to end with the help of a rocket engine? The answer is simple: it is unprofitable, and for a sufficiently heavy descent vehicle it is simply impossible.

The point is this. To launch a satellite, that is, to accelerate it to the first cosmic speed, a launch vehicle is required, the weight of which at the start should be approximately 50 times greater than the weight of the satellite. If we want to launch a satellite weighing 5 tons, then we need a rocket weighing 250 tons. If we want to return a satellite to Earth, we must decelerate it from first space velocity to zero - to ensure a soft landing. And this will require the same rocket - weighing 200 tons. We must take it with us when the ship starts from Earth. But then we have to put into orbit not 5 tons of cargo, but already 255 tons. And to do this, you need to take a rocket weighing 12,700 tons. In order to lift a rocket off the surface of the Earth, its thrust at the start must be at least a little more than its starting weight, that is, in this case, approximately 13,000 tons. But there are no such rockets yet - the most powerful modern rocket so far has a thrust of about 3,500 tons.

It is also clear that the cost of such a flight increases many times over.

Thus, it is much more profitable to use air resistance for the main braking during landing on the Earth. This also applies to landing on other planets with an atmosphere, such as Venus, Mars, Jupiter, etc. Landing on celestial bodies without an atmosphere, such as the Moon, is another matter. There's nothing you can do about it - you can only slow down the engines.

Let's return to the descent of the ship to the Earth (or to another planet with an atmosphere), namely, to the moment when the descent vehicle had just deorbited and went towards the Earth. It is very important how steep the trajectory of its flight will be. Even the most trained astronauts will die if their body weight becomes ten to thirteen times more than on Earth. Indeed, imagine that a load of ten times your own weight is heaped on you - you will be crushed by it. The astronauts will find themselves in the same position.

But too flat trajectory should not be either. Otherwise, the ship will fly to Earth for a very long time, as a result of which it will heat up too much and the temperature inside it will become more than the astronauts can withstand.

What determines the steepness of the trajectory? If the braking engine is turned on longer than necessary, the descent vehicle will go too steeply. Exactly the same result will be obtained if the traction force is greater than necessary. The steepness of the trajectory also depends on the direction of the engine nozzle during deceleration.

This is especially important in the case of uncontrolled—ballistic—descent. If the descent vehicle has the shape of a ball, then such a ship does not have an aerodynamic quality (lifting force). This means that during its descent, even in dense layers of the atmosphere, astronauts have no way to change the trajectory. The descent takes place along the so-called ballistic trajectory(a stone will fall along such a trajectory if you throw it from the top of a mountain in a horizontal direction) and is called ballistic, or uncontrolled, descent. The entire trajectory of such a descent, including the landing site, is determined already at the moment the braking engine stops working, when the ship has just left orbit. If the slope is set incorrectly (for example, due to the fact that the brake engine has worked for a few seconds more or less than required), the descent vehicle will land several tens and even hundreds of kilometers closer or farther than expected. And this means that the ship can land in the mountains, in the taiga or at sea, and not in the flat steppe. Of course, the descent vehicle will not sink and the cosmonauts will not die, even if the ship sank into the water or into the taiga—the cosmonauts have a walkie-talkie, flares, food supplies, etc. with risk, and with additional difficulties. Imagine, for example, what would happen if they landed on the side of a high and steep mountain.

These difficulties and troubles can be avoided if the descent vehicle is given a shape that has a lifting force. To do this, the shape of the apparatus must be asymmetrical with respect to the direction of flight. It is this shape, called segmental-conical, that modern descent vehicles have.

When the axis of the descent vehicle coincides with the direction of flight (the angle of attack is zero), the lift force is zero. By changing the angle of attack, that is, the inclination of the descent vehicle relative to the flight axis, the cosmonauts thereby increase or decrease the lift force and, due to this, can change the descent trajectory and choose the landing site. In addition, overloads can also be regulated in this way.

Such a descent vehicle flies with a segmental part forward. In this position, the air resistance is much greater than if it were flying conically forward. And the greater the resistance, the faster the ship slows down. If the craft were to fly conically forward, it would approach the Earth's surface at too high a speed.

Segmental-conical descent vehicles from a height of 20-30 kilometers descend by parachute, just like spherical ones.

Introduction

Also, for both devices, the main target was the Moon. The USA did not spare money for the lunar race, because until 1966 the USSR had priority in all significant space achievements. The first satellite, the first lunar stations, the first man in orbit and the first man in outer space - all these achievements were Soviet. The Americans struggled to "catch up and overtake" Soviet Union. And in the USSR, the task of a manned lunar program against the backdrop of space victories was overshadowed by other urgent tasks, for example, it was necessary to catch up with the United States in terms of the number ballistic missiles. Manned lunar programs are a separate big conversation, but here we will talk about vehicles in an orbital configuration, such as they met in orbit on July 17, 1975. Also, since the Soyuz spacecraft has been flying for many years and has undergone many modifications, speaking of the Soyuz, we will mean versions close in time to the Soyuz-Apollo flight.

Launch vehicles

The USSR decided to use a new modification of the R-7 rocket family to launch a new spacecraft into near-Earth orbit. On the Voskhod launch vehicle, the third-stage engine was replaced with a more powerful one, which increased the carrying capacity from 6 to 7 tons. The ship could not have a diameter of more than 3 meters, because in the 60s, analog control systems could not stabilize the over-caliber fairings.

On the left is the scheme of the Soyuz launch vehicle, on the right is the launch of the Soyuz-19 spacecraft of the Soyuz-Apollo mission

In the United States, the Saturn-I launch vehicle, specially designed for the Apollos, was used for orbital flights. In the -I modification, it could put 18 tons into orbit, and in the -IB modification, 21 tons. The diameter of the Saturn exceeded 6 meters, so the restrictions on the size of the spacecraft were minimal.

On the left is a Saturn-IB in a section, on the right is the launch of the Apollo spacecraft of the Soyuz-Apollo mission

In size and weight, the Soyuz is lighter, thinner and smaller than the Apollo. "Soyuz" weighed 6.5-6.8 tons and had a maximum diameter of 2.72 m. "Apollo" had a maximum mass of 28 tons (in the lunar version, fuel tanks were not completely filled for near-Earth missions) and a maximum diameter of 3, 9 m

Appearance

"Soyuz" and "Apollo" implemented the already standard scheme dividing the ship into compartments. Both ships had an instrument-aggregate compartment (in the USA it is called a service module), a descent vehicle (command module). The Soyuz descent vehicle turned out to be very cramped, so a household compartment was added to the ship, which could also be used as an airlock for spacewalks. On the Soyuz-Apollo mission american ship also had a third module, a special lock chamber for transition between ships.

According to the Soviet tradition, the Soyuz was launched entirely under the fairing. This made it possible not to care about the aerodynamics of the ship during launch and to place fragile antennas, sensors, solar panels and other elements on the outer surface. Also, the household compartment and the descent vehicle are covered with a layer of space thermal insulation. The Apollos continued the American tradition - the launch vehicle was only partially closed, the nose was covered by a ballistic cover, made structurally together with the rescue system, and from the tail the ship was closed with an adapter-fairing.

"Soyuz-19" in flight, shooting from the board of "Apollo". Dark green coating - thermal insulation

Apollo, shot from the Soyuz. On the main engine, it seems that the paint has swelled in places

"Union" of a later modification in the context

"Apollo" in the cut

The shape of the descent vehicle and thermal protection

The Soyuz and Apollo descent vehicles are more similar to each other than they were in previous generations space ships. In the USSR, the designers abandoned the spherical descent vehicle - when returning from the Moon, it would require a very narrow entry corridor (maximum and minimum height between which you need to get for a successful landing) would create an overload of more than 12 g, and the landing area would be measured in tens, if not hundreds, of kilometers. The conical descent vehicle created lift during braking in the atmosphere and, turning, changed its direction, controlling the flight. When returning from the earth's orbit, the overload decreased from 9 to 3-5 g, and when returning from the moon - from 12 to 7-8 g. The controlled descent significantly expanded the entry corridor, increasing the reliability of the landing, and greatly reduced the size of the landing area, facilitating the search and evacuation of astronauts.

Calculation of an asymmetric flow around a cone during braking in the atmosphere

Soyuz and Apollo descent vehicles

The diameter of 4 m, chosen for the Apollo, made it possible to make a cone with a half-angle of 33°. Such a descent vehicle has an aerodynamic quality of about 0.45, and its side walls practically do not heat up during braking. But its drawback was two points of stable equilibrium - Apollo had to enter the atmosphere with its bottom oriented in the direction of flight, because if it entered the atmosphere sideways, it could roll over into the "nose forward" position and kill the astronauts. A diameter of 2.7 m for the Soyuz made such a cone irrational - too much space was wasted. Therefore, a descent vehicle of the "headlight" type was created with a half-angle of only 7°. It uses space efficiently, has only one point of stable equilibrium, but its lift-to-drag ratio is lower, on the order of 0.3, and thermal protection is required for the side walls.

Already mastered materials were used as a heat-shielding coating. In the USSR, fabric-based phenol-formaldehyde resins were used, and in the USA, epoxy resin on a fiberglass matrix. The mechanism of operation was the same - the thermal protection burned and collapsed, creating an additional layer between the ship and the atmosphere, and the burnt particles took on and carried away thermal energy.

Thermal protection material "Apollo" before and after the flight

Propulsion system

Soyuz-19 feed, engine nozzles are clearly visible

Apollo attitude thrusters close-up

landing system

Apollo landing pattern

In the USSR, they traditionally landed a ship on land. Ideologically, the landing system develops the parachute-jet landing of Voskhodov. After dropping the lid of the parachute container, the exhaust, braking and main parachutes are fired in succession (a spare is installed in case of system failure). The ship descends on one parachute, at an altitude of 5.8 km the heat shield is dropped, and at a height of ~1 m jet engines soft landing (DMP). The system turned out to be interesting - the work of the DMP creates spectacular shots, but the comfort of landing varies in a very wide range. If the astronauts are lucky, then the impact on the ground is almost imperceptible. If not, then the ship can hit the ground sensitively, and if you are not at all lucky, then it will also capsize on its side.

Landing pattern

Perfectly normal operation of the DMP

The bottom of the descent vehicle. Three circles from above - DMP, three more - from the opposite side

Emergency Rescue System

From left to right SAS "Apollo", SAS "Soyuz", various versions of SAS "Soyuz"

Thermoregulation system

Means of providing EVA

EVA "Apollo 9"

Docking system

Docking mechanism "Apollo". By the way, it was also used in the Soyuz-Apollo program, with its help the command module docked with the airlock

Scheme of the Soyuz docking mechanism, first version

"Soyuz-19", front view. The docking station is clearly visible

Cabin and equipment

Control panel, view from the left seat

Control Panel. On the left are the flight controls, in the center - attitude control engines, emergency indicators on top, communications below. On the right side are fuel, hydrogen and oxygen indicators and power management

Even though the equipment of the Soyuz was simpler, it was the most advanced for the Soviet ships. The ship was the first to have an on-board digital computer, and the ship's systems included equipment for automatic docking. For the first time in space, multifunctional cathode ray tube indicators were used.

Soyuz spacecraft control panel

Power supply system

Conclusion

But a very high price was paid for this success. Both Soyuz and Apollo were the first ships in which people died. What is even sadder, if the designers, engineers and workers were less in a hurry and after the first successes would not cease to be afraid of space, then Komarov, Dobrovolsky, Volkov, Patsaev, Grissom, White and Cheffee

Is it so easy to put a person in a jar or about the design of manned spacecraft January 3, 2017

Spaceship. Surely many of you, having heard this phrase, imagine something huge, complex and densely populated, a whole city in space. So I once imagined spaceships and I, and numerous science fiction films and books actively contribute to this.

It's probably good that the authors of films are limited only by fantasy, unlike space technology design engineers. At least in the cinema, we can enjoy gigantic volumes, hundreds of compartments and thousands of crew members...

A real spaceship is not at all impressive in size:

The photo shows the Soviet Soyuz-19 spacecraft, taken by American astronauts from the Apollo spacecraft. It can be seen that the ship is quite small, and given that the habitable volume does not occupy the entire ship, it is obvious that it must be quite crowded there.

It is not surprising: large size is a large mass, and mass is enemy number one in astronautics. Therefore, spacecraft designers try to make them as light as possible, often at the expense of crew comfort. Notice how crowded the Soyuz is:

American ships in this regard are not particularly different from Russian ones. For example, here is a photo of Ed White and Jim McDivit in the Gemini spacecraft.

Only the crews of the Space Shuttle could boast of at least some freedom of movement. They had two relatively spacious compartments at their disposal.

Flight deck (actually the control cabin):

The middle deck (this is a household compartment with sleeping places, a toilet, a pantry and an airlock):

Unfortunately, the Soviet ship Buran, similar in size and layout, has never flown in a manned mode, like the TKS, which still has a record habitable volume among all ships ever designed.

But habitable volume is far from the only requirement for a spacecraft. I have heard statements like this: "They put a man in aluminum can and sent to spin around Mother Earth. "This phrase, of course, is incorrect. So how does a spaceship differ from a simple metal barrel?

And the fact that the spacecraft must:
- Provide the crew with a breathable gas mixture,
- remove carbon dioxide and water vapor exhaled by the crew from the habitable volume,
- Provide acceptable for the crew temperature regime,
- Have a sealed volume sufficient for the life of the crew,
- Provide the ability to control the orientation in space and (optionally) the ability to perform orbital maneuvers,
- Have the necessary supplies of food and water for the life of the crew,
- Ensure the possibility of a safe return of the crew and cargo to the ground,
- Be as light as possible
- Have an emergency rescue system that allows the crew to return to the ground in an emergency at any stage of the flight,
- Be very reliable. Any one failure of the equipment must not lead to the cancellation of the flight, any second failure must not endanger the life of the crew.

As you can see, this is no longer a simple barrel, but a complex technological device, stuffed with a variety of equipment, having engines and a supply of fuel for them.

Here, for example, is the layout of the first-generation Soviet spacecraft Vostok.

It consists of a sealed spherical capsule and a conical instrument-aggregate compartment. Almost all ships have such an arrangement, in which most of the instruments are placed in a separate unpressurized compartment. This is necessary to save weight: if all the devices are placed in a sealed compartment, this compartment would turn out to be quite large, and since it needs to hold Atmosphere pressure and withstand significant mechanical and thermal loads during entry into the dense layers of the atmosphere during descent to the ground, its walls must be thick, durable, which makes the entire structure very heavy. And an unpressurized compartment, which will separate from the descent vehicle upon return to earth and burn up in the atmosphere, does not need strong heavy walls. The descent vehicle without unnecessary instruments during the return turns out to be smaller and, accordingly, lighter. A spherical shape is also given to it to reduce mass, because of all geometric bodies A sphere of the same volume has the smallest surface area.

The only spacecraft where all the equipment was placed in a sealed capsule is the American Mercury. Here is his photo in the hangar:

One person could fit in this capsule, and then with difficulty. Realizing the inefficiency of such an arrangement, the Americans made their next series of Gemini ships with a detachable leaky instrument-aggregate compartment. In the photo, this is the back of the ship in white:

By the way, this compartment is painted white for a reason. The fact is that the walls of the compartment are pierced by many tubes through which water circulates. This is a system for removing excess heat received from the Sun. Water takes heat from inside the habitable compartment and gives it to the surface of the instrument-aggregate compartment, from where heat is radiated into space. To make these radiators less heated in direct sunlight, they were painted white.

On the Vostok ships, the radiators were located on the surface of the conical instrument-aggregate compartment and were closed with shutters similar to blinds. By opening a different number of shutters, it was possible to regulate the heat transfer of the radiators, and hence the temperature regime inside the ship.

On Soyuz ships and their cargo counterparts Progress, the heat removal system is similar to Gemini. Pay attention to the color of the surface of the instrument-aggregate compartment. Of course, white :)

Inside the instrument-assembly compartment are sustainer engines, low-thrust shunting engines, a supply of fuel for all this stuff, batteries, oxygen and water supplies, and part of the on-board electronics. Outside, radio communication antennas, proximity antennas, various orientation sensors and solar panels are usually installed.

The descent vehicle, which simultaneously serves as the cabin of the spacecraft, contains only those elements that are needed during the descent of the vehicle in the atmosphere and a soft landing, as well as what should be directly accessible to the crew: a control panel, a radio station, an emergency supply of oxygen, parachutes , cassettes with lithium hydroxide to remove carbon dioxide, soft landing engines, lodgements (chairs for astronauts), emergency rescue kits in case of landing at an off-design point, and, of course, the astronauts themselves.

Soyuz ships have one more compartment - household:

It contains what you need in a long flight, but what you can do without at the stage of launching the ship into orbit and upon landing: scientific instruments, food supplies, Cessation and sanitary device (toilet), spacesuits for extravehicular activities, sleeping bags and other household items.

There is a well-known case with the Soyuz TM-5 spacecraft, when, in order to save fuel, the household compartment was fired not after issuing a braking impulse to deorbit, but before. Only now there was no braking impulse: the orientation system failed, then it was not possible to start the engine. As a result, the cosmonauts had to stay in orbit for another day, and the toilet remained in the shot-out amenity compartment. It is difficult to convey what inconvenience the astronauts experienced during these days, until, finally, they managed to land safely. After this incident, they decided to score on such fuel economy and shoot the household compartment together with the instrument-aggregate after braking.

That's how many all sorts of difficulties turned out to be in the "bank". We will separately go over each type of spacecraft of the USSR, the USA and China in the following articles. Keep for updates.

2.50: "The descent of the SA from heights from 90 to 40 km is detected and accompanied by radar stations".

Memorize these radar data.

We will return to them when we discuss what and how the USSR could monitor the Apollos 50 years ago and why it never did.

live video

Turn on Russian subtitles.

Manned spacecraft landing

Introduction

It is worth mentioning right away that the organization of a manned flight is quite different from unmanned missions, but in any case, all work on dynamic operations in space can be divided into two stages: design and operational, only in the case of manned missions, these stages, as a rule, take significantly longer. more time. This article deals mainly with the operational part, since the work on the ballistic design of the descent is ongoing and includes various studies to optimize various factors that affect the safety and comfort of the crew during landing.

For 40 days

The first estimated descent calculations are being carried out in order to determine the landing areas. Why is this being done? Currently regular controlled descent Russian ships can only be made in 13 fixed landing areas located in the Republic of Kazakhstan. This fact imposes a lot of restrictions related primarily to the need for preliminary coordination with our foreign partners of all dynamic operations. The main difficulties arise when planting in autumn and spring - this is due to agricultural work in the planting areas. This fact must be taken into account, because in addition to ensuring the safety of the crew, it is also necessary to ensure the safety of the local population and the search and rescue service (SRS). In addition to regular landing areas, there are also landing areas during a ballistic descent stall, which must also be suitable for landing.

For 10 days

Preliminary calculations for descent trajectories are being refined, taking into account the latest data on the current ISS orbit and the characteristics of the docked spacecraft. The fact is that a fairly long period of time passes from the moment of launch to descent, and the mass-centering characteristics of the apparatus change, in addition, a large contribution is made by the fact that, together with the astronauts, payloads from the station return to Earth, which can significantly change the position center of gravity of the descent vehicle. Here it is necessary to explain why this is important: the shape of the Soyuz spacecraft resembles a headlight, i.e. it does not have any aerodynamic controls, but to obtain the necessary landing accuracy, it is necessary to control the trajectory in the atmosphere. To do this, the Soyuz provides for a gas-dynamic control system, but it is not able to compensate for all deviations from the nominal trajectory, so an extra balancing weight is artificially added to the design of the device, the purpose of which is to shift the center of pressure from the center of mass, which will allow you to control the descent trajectory, turning over on a roll . Updated data on the main and backup schemes are sent to the MSS. According to these data, a flight is made over all the calculated points and a conclusion is made on the possibility of landing in these areas.

For 1 day

The descent trajectory is finally being refined, taking into account the latest measurements of the ISS position, as well as the forecast of the wind situation in the main and reserve landing areas. This must be done due to the fact that at an altitude of about 10 km the parachute system opens. By this point in time, the descent control system has already done its job and cannot correct the trajectory in any way. In fact, only wind drift acts on the apparatus, which cannot be ignored. The figure below shows one of the wind drift modeling options. As you can see, after the introduction of the parachute, the trajectory changes greatly. Wind drift can sometimes be up to 80% of the permissible radius of the dispersion circle, so the accuracy of the weather forecast is very important.

Day of descent:
In addition to the ballistic and search and rescue services, many more units are involved in ensuring the descent of the spacecraft to the ground, such as:

• transport ship control service;
• ISS control service;
• the service responsible for the health of the crew;
• telemetry and command services, etc.

Only after the report on the readiness of all services, the flight managers can make a decision to carry out the descent according to the planned program.
After that, the passage hatch is closed and the spacecraft is undocked from the station. A separate service is responsible for undocking. Here it is necessary to calculate in advance the direction of undocking, as well as the impulse that must be applied to the device in order to prevent a collision with the station.

When calculating the descent trajectory, the undocking scheme is also taken into account. After undocking the ship, there is still some time before the braking engine is switched on. At this time, all equipment is checked, trajectory measurements are taken, and the landing point is specified. This is the last moment when something else can be clarified. Then the brake motor is turned on. This is one of the most important stages of the descent, so it is constantly monitored. Such measures are necessary in order to understand in the event of an emergency situation what scenario to go on. During the normal processing of the pulse, after some time, the separation of the spacecraft compartments occurs (the descent vehicle is separated from the domestic and instrument-aggregate compartments, which then burn out in the atmosphere).

If, upon entry into the atmosphere, the descent control system decides that it is not able to ensure the landing of the descent vehicle at the point with the required coordinates, then the ship “breaks down” into a ballistic descent. Since all this is already happening in the plasma (there is no radio communication), it is possible to establish on which trajectory the apparatus is moving only after the resumption of radio communication. If there was a breakdown on a ballistic descent, it is necessary to quickly clarify the intended landing point and transfer it to the search and rescue service. In the case of a regular controlled descent, the spacecraft specialists begin to “guide” the ship even in flight, and we can see in live descent of the device on a parachute and even, if you're lucky, the operation of the soft landing engines (as in the figure).

After that, you can already congratulate everyone, shout cheers, open champagne, hug, etc. Officially, ballistic work is completed only after receiving GPS coordinates landing points. This is necessary for the post-flight assessment of the miss, which can be used to assess the quality of our work.
Photos taken from the site: www.mcc.rsa.ru

Spacecraft landing accuracy

Ultra-precise landings or NASA's "lost technologies"

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For the umpteenth time I repeat that before freely talking about the deepest antiquity, where 100,500 soldiers unrestrictedly made dashing forced marches over arbitrary terrain, it is useful to practice "on cats" © "Operation Y", for example, on events only half a century ago - " American flights to the moon.

The defenders of NASA something densely went. And a month has not passed since, as a very popular blogger Zelenykot, who turned out to be red in fact, spoke on the topic:

"Invited to GeekPicnic to talk about space myths. Of course, I took the most running and popular: the myth of the lunar conspiracy. In an hour, we analyzed in detail the most common misconceptions and the most common questions: why the stars are not visible, why the flag flutters, where the lunar soil is hidden, how they managed to lose the tapes with the recording of the first landing, why F1 rocket engines are not made and other questions."

Wrote him a comment:

"Fine, Hobotov! In the furnace of refutation "the flag is jerking - there are no stars - the pictures are faked"!
Better explain only one thing: how did the Americans "when returning from the Moon" from the second cosmic speed landed with an accuracy of + -5 km, which is still unattainable even from the first cosmic speed, from near-Earth orbit?
Again "lost NASA technology"? G-d-d“I haven’t received an answer yet, and I doubt that there will be anything sane, it’s not gibberish-hahanki about the flag and the space window.

I explain what the ambush is. A.I. Popov in the article "" writes: "According to NASA, the "lunar" Apollos No. 8,10-17 splashed down with deviations from the calculated points of 2.5; 2.4; 3; 3.6; 1.8; 1; 1.8; 5.4; and 1.8 km, respectively; an average of ± 2 km That is, the circle of impact for the "Apollo" was supposedly extremely small - 4 km in diameter.

Our proven Soyuz even now, 40 years later, land ten times less accurately (Fig. 1), although the descent trajectories of Apollo and Soyuz are identical in their physical essence.

for details see:

"... the modern accuracy of the landing of the Soyuz is ensured by the design provided for in 1999 when designing the improved Soyuz-TMS" lowering the commissioning height parachute systems to improve the accuracy of landing (15–20 km along the radius of the circle of the total spread of landing points).

From the late 1960s to the 21st century, the Soyuz landing accuracy during normal, standard descent was within ± 50-60 km from the calculated point as envisaged in the 1960s.

Naturally, there were also emergency situations, for example, in 1969, the landing "" with Boris Volynov on board occurred with an undershoot of 600 km to the calculated point.

Before the Soyuz, in the era of the Vostoks and Voskhods, deviations from the calculated point were even more abrupt.

April 1961 Yu. Gagarin makes one revolution around the Earth. Due to a failure in the braking system, Gagarin landed not in the planned area near the Baikonur cosmodrome, but 1800 km to the west, in the Saratov region.

March 1965 P. Belyaev, A. Leonov 1 day 2 hours 2 minutes The first human spacewalk in the world automatics failed Landing took place in the snowy taiga 200 km from Perm, far from populated areas. The cosmonauts spent two days in the taiga until they were discovered by rescuers ("On the third day they pulled us out of there."). This was due to the fact that the helicopter could not land nearby. The landing site for the helicopter was equipped the next day, 9 km from the place where the astronauts landed. The overnight stay was carried out in a log house built on the landing site. Astronauts and rescuers got to the helicopter on skis"

A direct descent like that of the Soyuz would, due to overloads, be incompatible with the life of the Apollo cosmonauts, because they would have to extinguish the second space velocity, and a safer descent using a two-dive scheme gives a spread over the landing point of hundreds and even thousands of kilometers:

That is, if the Apollos splashed down with unrealistic accuracy even by today's standards in a direct single-dive scheme, then the astronauts would either have to burn out due to the lack of high-quality ablative protection, or die / get seriously injured from overloads.

But numerous television, film and photography invariably recorded that the astronauts who allegedly descended from the second cosmic velocity in the Apollos were not just alive, but very merry lively ones.

And this despite the fact that the Americans at the same time could not normally launch even a monkey even into low Earth orbit, see.

Vitaly Yegorov, a red-haired Zelenykot, who so zealously defends the myth of "Americans on the Moon" is a paid propagandist, public relations specialist for the private space company Dauria Aerospace, which has dug itself into the Skolkovo Technopark in Moscow and actually exists on American money (emphasis mine) :

"The company was founded in 2011. The Roscosmos license for space activities was obtained in 2012. Until 2014, it had divisions in Germany and the USA. At the beginning of 2015, production activities were almost curtailed everywhere except Russia. The company is engaged in the creation of small spacecraft (satellites) and sale of components for them. Dauria Aerospace raised $20 million from I2bf venture fund in 2013. The company sold two of its satellites to the American one at the end of 2015, thereby receiving the first income from their activities."

"In one of his next “lectures”, Yegorov arrogantly flaunted, smiling with his charming smile on duty, that the American fund “I2BF Holdings Ltd. Purpose I2BF-RNC Strategic Resources Fund, under the auspices of NASA, has invested $35 million in DAURIA AIRSPACE.

It turns out that Mr. Egorov is not just a subject of the Russian Federation, but a full-fledged foreign resident, whose activities are financed from American funds, with which I congratulate all the voluntary Russian sponsors of the BUMSTARTER crowdfunding, who have invested their hard-earned money in the project of a foreign company, which has a very specific ideological character."

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