When spacecraft fly in near-Earth orbits, conditions arise on board that humans usually do not encounter on Earth. The first of them is long-term weightlessness.
As you know, the weight of a body is the force with which it acts on the support. If both the body and the support move freely under the influence of gravity with the same acceleration, i.e., fall freely, then the weight of the body disappears. This property of freely falling bodies was established by Galileo. He wrote: “We feel a weight on our shoulders when we try to stop it from falling freely. But if we begin to move down at the same speed as the load lying on our back, then how can it press and burden us? This is the same as if we wanted to hit someone with a spear who is running in front of us at the same speed with which the spear is moving.”
When a spacecraft moves in low-Earth orbit, it is in a state free fall. The device falls all the time, but cannot reach the surface of the Earth, because it is given such a speed that makes it rotate around it endlessly (Fig. 1). This is the so-called first escape velocity (7.8 km/s). Naturally, all objects on board the apparatus lose their weight, in other words, a state of weightlessness sets in.
Rice. 1. The emergence of weightlessness on a spacecraft
The state of weightlessness can be reproduced on Earth, but only for short periods of time. For this, they use, for example, zero-gravity towers - tall buildings, inside which the research container falls freely. The same condition occurs on board aircraft flying with the engines turned off along special elliptical trajectories. In towers, the state of weightlessness lasts several seconds, on airplanes - tens of seconds. On board a spacecraft, this state can last indefinitely.
This state of complete weightlessness is an idealization of the conditions that actually exist during space flight. In fact, this state is disrupted due to various small accelerations acting on the spacecraft during orbital flight. In accordance with Newton's 2nd law, the appearance of such accelerations means that small mass forces begin to act on all objects located on the spacecraft, and, consequently, the state of weightlessness is violated.
Small accelerations acting on a spacecraft can be divided into two groups. The first group includes accelerations associated with changes in the speed of movement of the apparatus itself. For example, due to resistance upper layers atmosphere, when the vehicle moves at an altitude of about 200 km, it experiences an acceleration of the order of 10 –5 g 0 (g 0 is the acceleration of gravity near the Earth’s surface, equal to 981 cm/s 2 ). When the spacecraft's engines are turned on to transfer it to a new orbit, it also experiences acceleration.
The second group includes accelerations associated with changes in orientation spaceship in space or with mass movements on board. These accelerations occur during the operation of the orientation system engines, during the movements of astronauts, etc. Typically, the magnitude of the accelerations created by the orientation engines is 10 –6 - 10 –4 g 0. Accelerations resulting from various activities astronauts, lie in the range 10 –5 - 10 –3 g 0 .
Speaking about weightlessness, the authors of some popular articles, dedicated space technology, use the terms “microgravity”, “world without gravity” and even “gravitational silence”. Since in a state of weightlessness there is no weight, but gravitational forces are present, these terms should be considered erroneous.
Let us now consider other conditions that exist on board spacecraft during their flight around the Earth. First of all, it is a deep vacuum. The pressure of the upper atmosphere at an altitude of 200 km is about 10–6 mm Hg. Art., and at an altitude of 300 km - about 10–8 mm Hg. Art. Such a vacuum can also be obtained on Earth. However, open outer space can be likened to a vacuum pump of enormous capacity, capable of very quickly pumping gas out of any spacecraft container (to do this, it is enough to depressurize it). In this case, however, it is necessary to take into account the effect of some factors leading to deterioration of the vacuum near the spacecraft: gas leakage from its internal parts, destruction of its shells under the influence of solar radiation, pollution of the surrounding space due to the operation of engines of orientation and correction systems.
A typical scheme of the technological process for the production of any material is that energy is supplied to the feedstock, ensuring the passage of certain phase transformations or chemical reactions, which lead to obtaining the desired product. Most natural spring energy for processing materials in space is the Sun. In low-Earth orbit, the solar radiation energy density is about 1.4 kW/m 2, with 97% of this value occurring in the wavelength range from 3 10 3 to 2 10 4 A. However direct use Using solar energy to heat materials poses a number of difficulties. Firstly, solar energy cannot be used in a darkened area of the spacecraft trajectory. Secondly, it is necessary to ensure constant orientation of radiation receivers towards the Sun. And this, in turn, complicates the operation of the spacecraft orientation system and can lead to an undesirable increase in accelerations that violate the state of weightlessness.
As for other conditions that can be implemented on board spacecraft ( low temperatures, use of rigid component solar radiation etc.), then their use in the interests of space production is not currently envisaged.
Notes:
Mass, or volumetric, forces are forces that act on all particles (elementary volumes) given body and whose magnitude is proportional to mass.
Brief summary of the meeting with Viktor Hartov, general designer Roscosmos on automatic space complexes and systems, in the past the general director of the NPO named after. S.A. Lavochkina. The meeting took place at the Museum of Cosmonautics in Moscow, as part of the project “ Space without formulas ”.
Full summary of the conversation.
My function is to carry out a unified scientific and technical policy. I devoted my whole life to automatic space. I have some thoughts, I’ll share them with you, and then I’m interested in your opinion.
Automatic space is multifaceted, and I would highlight 3 parts.
1st - applied, industrial space. These are communications, remote sensing of the Earth, meteorology, navigation. GLONASS, GPS is an artificial navigation field of the planet. The one who creates it does not receive any benefit; those who use it benefit.
Earth imaging is a very commercial field. Everyone operates in this area normal laws market. Satellites need to be made faster, cheaper and of better quality.
Part 2 - scientific space. The very cutting edge of humanity's knowledge of the Universe. Understand how it formed 14 billion years ago, the laws of its development. How did the processes go on on neighboring planets, how can we make sure that the Earth does not become like them?
The baryonic matter that is around us - the Earth, the Sun, nearby stars, galaxies - all this is only 4-5% of total mass Universe. Eat dark energy, dark matter. What kind of kings of nature are we, if all the known laws of physics are only 4%. Now they are “digging a tunnel” to this problem from two sides. On the one hand: the Large Hadron Collider, on the other - astrophysics, through the study of stars and galaxies.
My opinion is that now we should push the capabilities and resources of humanity onto the same flight to Mars, poison our planet with a cloud of launches, burning ozone layer- this is not the most right action. It seems to me that we are in a hurry, trying with our locomotive forces to solve a problem that needs to be worked on without fuss, with a full understanding of the nature of the Universe. Find the next layer of physics, new laws to overcome all this.
How long will it last? It is unknown, but we need to accumulate data. And here the role of space is great. The same Hubble, which has been working for a lot of years, is beneficial; James Webb will soon be replaced. What is fundamentally different about scientific space is that it is something that a person can already do; there is no need to do it a second time. We need to do new and next things. Every time there is new virgin soil - new bumps, new problems. Rarely scientific projects are done on time as planned. The world is quite calm about this, except for us. We have law 44-FZ: if a project is not submitted on time, then there will be fines immediately, ruining the company.
But we already have Radioastron flying, which will be 6 years old in July. A unique companion. It has a 10 meter antenna high precision. Its main feature is that it works together with ground-based radio telescopes, in interferometer mode, and very synchronously. Scientists are simply crying with happiness, especially academician Nikolai Semenovich Kardashev, who in 1965 published an article where he substantiated the possibility of this experiment. They laughed at him, but now he happy man, who conceived this and now sees the results.
I would like our astronautics to make scientists happy more often and launch more such advanced projects.
The next "Spektr-RG" is in the workshop, work is underway. It will fly one and a half million kilometers from Earth to point L2, we will be working there for the first time, we are waiting with some trepidation.
Part 3 - “ new space" About new tasks in space for automata in low-Earth orbit.
On-orbit service. This includes inspection, modernization, repairs, and refueling. The task is very interesting from an engineering point of view, and it is interesting for the military, but it is economically very expensive, while the possibility of maintenance exceeds the cost of the serviced device, so this is advisable for unique missions.
When satellites fly as much as you want, two problems arise. The first is that the devices are becoming obsolete. The satellite is still alive, but on Earth the standards have already changed, new protocols, diagrams, and so on. The second problem is running out of fuel.
Fully digital payloads are being developed. By programming it can change modulation, protocols, and purpose. Instead of a communications satellite, the device can become a relay satellite. This topic is very interesting, I mean military application I do not speak. It also reduces production costs. This is the first trend.
The second trend is refueling and service. Experiments are now being carried out. Projects involve servicing satellites that were made without taking this factor into account. In addition to refueling, delivery of an additional payload that is sufficiently autonomous will also be tested.
The next trend is multi-satellite. The flows are constantly growing. M2M is being added - this Internet of things, virtual presence systems, and much more. Everyone wants to use streams with mobile devices, with minimal delays. In low orbit, the satellite's power requirements are reduced and the volume of equipment is reduced.
SpaceX has submitted an application to the Federal Communications Commission to create a 4,000-spacecraft system for a global high-speed network. In 2018, OneWeb begins to deploy a system consisting initially of 648 satellites. The project was recently expanded to 2000 satellites.
Approximately the same picture is observed in the remote sensing area - you need to see any point on the planet at any time, in maximum quantity spectra, with maximum detail. We need to put a damn cloud of small satellites into low orbit. And create a super-archive where information will be dumped. This is not even an archive, but an updated model of the Earth. And any number of clients can take what they need.
But pictures are the first stage. Everyone needs processed data. This is an area where there is scope for creativity - how to “collect” applied data from these pictures, in different spectra.
But what does a multi-satellite system mean? Satellites must be cheap. The satellite must be light. A factory with ideal logistics is tasked with producing 3 pieces per day. Now they make one satellite every year or every year and a half. You need to learn how to solve the target problem using the multi-satellite effect. When there are many satellites, they can solve a problem as one satellite, for example, create a synthetic aperture, like Radioastron.
Another trend is the transfer of any task to the plane of computational tasks. For example, radar is in sharp conflict with the idea small lung satellite, it needs power to send and receive a signal, and so on. There is only one way: the Earth is irradiated by a mass of devices - GLONASS, GPS, communication satellites. Everything shines on the Earth and something is reflected from it. And the one who learns to wash out useful data from this garbage will be the king of the hill in this matter. This is a very difficult computational problem. But she's worth it.
And then, imagine: now all the satellites are controlled like a Japanese toy [Tomagotchi]. Everyone is very fond of the tele-command management method. But in the case of multi-satellite constellations, complete autonomy and intelligence of the network are required.
Since the satellites are small, the question immediately arises: “is there already so much debris around the Earth”? Now there is an international garbage committee, which has adopted a recommendation stating that the satellite must definitely leave orbit within 25 years. This is normal for satellites at an altitude of 300-400 km; they are slowed down by the atmosphere. And OneWeb devices will fly at an altitude of 1200 km for hundreds of years.
The fight against garbage is a new application that humanity has created for itself. If the garbage is small, then it needs to be accumulated in some kind of large net or in a porous piece that flies and absorbs small debris. And if there is large garbage, then it is undeservedly called garbage. Humanity has spent money, the oxygen of the planet, and launched the most valuable materials into space. Half the happiness is that it has already been taken out, so you can use it there.
There is such a utopia that I run around with, a certain model of a predator. The device that reaches this valuable material turns it into a substance like dust in a certain reactor, and part of this dust is used in a giant 3D printer to create part of its own kind in the future. This is still a distant future, but this idea solves the problem, because any pursuit of garbage is the main curse - ballistics.
We do not always feel that humanity is very limited in terms of maneuvers near the Earth. Changing the orbital inclination and altitude is a colossal expenditure of energy. Our life was greatly spoiled by the vivid visualization of space. In films, in toys, in “Star Wars”, where people fly back and forth so easily and that’s it, the air doesn’t bother them. A disservice our industry has benefited from this “believable” visualization.
I am very interested to hear your opinion on the above. Because now we are holding a campaign at our institute. I gathered young people and said the same thing, and invited everyone to write an essay on this topic. Our space is flabby. We have gained experience, but our laws, like chains on our feet, sometimes get in the way. On the one hand, they are written in blood, everything is clear, but on the other: 11 years after the launch of the first satellite, man set foot on the Moon! From 2006 to 2017 nothing has changed.
Now there are objective reasons - everything physical laws developed, all fuel, materials, basic laws and all technological advances based on them were applied in previous centuries, because new physics No. Besides this, there is another factor. When Gagarin was allowed in, the risk was enormous. When the Americans flew to the Moon, they themselves estimated that there was 70% risk, but then the system was such that...
Gave room for error
Yes. The system recognized that there was a risk, and there were people who put their future on the line. “I decide that the Moon is solid” and so on. There was no mechanism above them that would prevent them from making such decisions. Now NASA is complaining: “The bureaucracy has crushed everything.” The desire for 100% reliability has been elevated to a fetish, but this is an endless approximation. And no one can make a decision because: a) there are no such adventurers except Musk, b) mechanisms have been created that do not give the right to take risks. Everyone is constrained by previous experience, which is materialized in the form of regulations and laws. And in this web, space moves. A clear breakthrough that is behind last years- this is the same Elon Musk.
My guess based on some data: it was NASA’s decision to grow a company that would not be afraid to take risks. Elon Musk sometimes lies, but he gets the job done and moves forward.
From what you said, what is being developed in Russia now?
We have a Federal Space Program and it has two goals. The first is to meet the needs of federal executive authorities. The second part is scientific space. This is Spektr-RG. And in 40 years we must learn to return to the Moon again.
To the Moon why this renaissance? Yes, because some amount of water has been noticed on the Moon near the poles. Checking that there is water there is the most important task. There is a version that comets have trained it over millions of years, then this is especially interesting, because comets arrive from other star systems.
Together with the Europeans, we are implementing the ExoMars program. The first mission had started, we had already arrived, and the Schiaparelli safely crashed to smithereens. We are waiting for mission No. 2 to arrive there. 2020 start. When two civilizations collide in the cramped “kitchen” of one apparatus, there are many problems, but it has already become easier. Learned to work in a team.
In general, scientific space is a field where humanity needs to work together. It is very expensive, does not provide profit, and therefore it is extremely important to learn how to combine financial, technical and intellectual forces.
It turns out that all problems of the FKP are solved in modern paradigm production of space technology.
Yes. Absolutely right. And until 2025 - this is the validity period of this program. There are no specific projects for the new class. There is an agreement with the leadership of Roscosmos, if the project is brought to a plausible level, then we will raise the issue of inclusion in the federal program. But what is the difference: we all have a desire to get our hands on budget money, but in the USA there are people who are ready to invest their money in such a thing. I understand that this is a voice crying in the desert: where are our oligarchs who invest in such systems? But without waiting for them, we are carrying out the starting work.
I believe that here you just need to click two calls. First, look for such breakthrough projects, teams that are ready to implement them and those who are ready to invest in them.
I know that there are such teams. We are consulting with them. Together we help them so that they can achieve their goals.
Is there a radio telescope planned for the Moon? And the second question is about space debris and the Kesler effect. Is this task relevant, and are any measures planned to be taken in this regard?
I'll start with the last question. I told you that humanity takes this very seriously, because it has created a garbage committee. Satellites need to be able to be deorbited or taken to a safe place. And so you need to make reliable satellites so that they “don’t die.” And ahead are such futuristic projects that I spoke about earlier: the Big Sponge, the “predator”, etc.
The “mine” could work in the event of some kind of conflict, if military operations take place in space. Therefore, we must fight for peace in space.
The second part of the question is about the Moon and the radio telescope.
Yes. Luna - on the one hand it’s cool. It seems to be in a vacuum, but there is a kind of dusty exosphere around it. The dust there is extremely aggressive. What kind of problems can be solved from the Moon - this still needs to be figured out. It is not necessary to install a huge mirror. There is a project - the ship is lowered and people are running away from it. different sides"cockroaches" that drag the cables, resulting in a large radio antenna. A number of such lunar radio telescope projects are floating around, but first of all you need to study and understand it.
A couple of years ago, Rosatom announced that it was preparing almost a preliminary design of a nuclear propulsion system for flights, including to Mars. Is this topic being developed somehow or is it frozen?
Yes, she's coming. This is the creation of a transport and energy module, TEM. There is a reactor there and the system converts it thermal energy into an electric one, and very powerful ion engines. There are a dozen key technologies, and work is underway on them. Very significant progress has been made. The design of the reactor is almost completely clear; very powerful 30 kW ion engines have been practically created. I recently saw them in a cell; they are being worked on. But the main curse is the heat, we need to drop 600 kW - that’s quite a task! Radiators under 1000 sq. m. They are currently working on finding other approaches. These are drip refrigerators, but they are still in the early phase.
Do you have any tentative dates?
The demonstrator is going to be launched somewhere before 2025. This is a worthwhile task. But this depends on several key technologies that are lagging behind.
The question may be half-joking, but what are your thoughts about the famous electromagnetic bucket?
I know about this engine. I told you that since I learned that there is dark energy and dark matter, I have stopped relying entirely on my high school physics textbook. The Germans carried out experiments, they are an accurate people, and they saw that there was an effect. And this completely contradicts my higher education. In Russia, they once did an experiment on the Yubileiny satellite with an engine without mass loss. There were for, there were against. After the tests, both sides received firm confirmation that they were right.
When the first Elektro-L was launched, there were complaints in the press, from the same meteorologists, that the satellite did not meet their needs, i.e. The satellite was scolded even before it broke.
It was supposed to work in 10 spectra. In terms of spectra, in 3, in my opinion, the quality of the picture was not the same as that coming from Western satellites. Our users are accustomed to completely commodity products. If there were no other pictures, meteorologists would be happy. The second satellite has been significantly improved, the mathematics has been improved, so now they seem to be satisfied.
Continuation of "Phobos-Grunt" "Boomerang" - will it be new project or will it be a repeat?
When Phobos-Grunt was being made, I was the director of the NPO named after. S.A. Lavochkina. This is an example when the amount of new exceeds a reasonable limit. Unfortunately, there was not enough intelligence to take everything into account. The mission should be repeated, in particular because it brings closer the return of soil from Mars. The groundwork will be applied, ideological, ballistic calculations, etc. And so, the technology must be different. Based on these backlogs that we will receive for the Moon, for something else... Where there will already be parts that will reduce the technical risks of a complete new one.
By the way, do you know that the Japanese are going to implement their “Phobos-Grunt”?
They don’t yet know that Phobos is a very scary place, everyone dies there.
They had an experience with Mars. And a lot of things died there too.
The same Mars. Before 2002, the States and Europe seemed to have 4 unsuccessful attempts get to Mars. But they showed American character, and every year they shot and learned. Now they make extremely beautiful things. I was at the Jet Propulsion Laboratory on landing of the Curiosity rover. By that time we had already destroyed Phobos. This is where I practically cried: their satellites have been flying around Mars for a long time. They structured this mission in such a way that they received a photo of the parachute that opened during the landing process. Those. They were able to obtain data from their satellite. But this path is not easy. They had several failed missions. But they continued and have now achieved some success.
The mission they crashed, Mars Polar Lander. Their reason for the failure of the mission was “underfunding.” Those. The government services looked at it and said, we didn’t give you money, it’s our fault. It seems to me that this is almost impossible in our realities.
Not that word. We need to find the specific culprit. On Mars we need to catch up. Of course, there is also Venus, which until now was considered a Russian or Soviet planet. Now serious negotiations are underway with the United States about jointly making a mission to Venus. The US wants landers with high-temperature electronics that will operate normally at high degrees, without thermal protection. You can make balloons or an airplane. Interesting project.
We express our gratitude
Spacecraft in all their diversity are both the pride and concern of humanity. Their creation was preceded by a centuries-old history of the development of science and technology. The space age, which allowed people to look at the world in which they live from the outside, has taken us to a new level of development. A rocket in space today is not a dream, but a matter of concern for highly qualified specialists who are faced with the task of improving existing technologies. About what types of spacecraft are distinguished and how they differ from each other, we'll talk in the article.
Definition
Spacecraft is a general name for any device designed to operate in space. There are several options for their classification. In the very simple case allocate spacecraft manned and automatic. The former, in turn, are divided into spaceships and stations. Different in their capabilities and purpose, they are similar in many respects in structure and equipment used.
Flight Features
After launch, any spacecraft goes through three main stages: insertion into orbit, flight itself and landing. The first stage involves the device developing the speed necessary to enter outer space. In order to get into orbit, its value must be 7.9 km/s. Complete overcoming of gravity involves the development of a second equal to 11.2 km/s. This is exactly how a rocket moves in space when its target is remote areas of the Universe.
After liberation from attraction, the second stage follows. In progress orbital flight The movement of spacecraft occurs by inertia, due to the acceleration given to them. Finally, the landing stage involves reducing the speed of the ship, satellite or station to almost zero.
"Filling"
Each spacecraft is equipped with equipment that matches the tasks it is designed to solve. However, the main discrepancy is related to the so-called target equipment, which is necessary precisely for obtaining data and various scientific research. Otherwise, the equipment of the spacecraft is similar. It includes the following systems:
- energy supply - most often supplied to spacecraft necessary energy solar or radioisotope batteries, chemical batteries, nuclear reactors;
- communication - carried out using a radio wave signal; at a significant distance from the Earth, accurate pointing of the antenna becomes especially important;
- life support - the system is typical for manned spacecraft, thanks to it it becomes possible for people to stay on board;
- orientation - like any other ships, spacecraft are equipped with equipment for permanent definition own position in space;
- movement - spacecraft engines allow changes in flight speed, as well as in its direction.
Classification
One of the main criteria for dividing spacecraft into types is the operating mode that determines their capabilities. Based on this feature, devices are distinguished:
- located in a geocentric orbit, or artificial earth satellites;
- those whose purpose is to study remote areas of space - automatic interplanetary stations;
- used to deliver people or necessary cargo into the orbit of our planet, they are called spaceships, can be automatic or manned;
- created for people to stay in space for a long period - this is;
- engaged in the delivery of people and cargo from orbit to the surface of the planet, they are called descent;
- those capable of exploring the planet, directly located on its surface, and moving around it are planetary rovers.
Let's take a closer look at some types.
AES (artificial earth satellites)
The first devices launched into space were artificial Earth satellites. Physics and its laws make launching any such device into orbit a difficult task. Any device must overcome the gravity of the planet and then not fall on it. To do this, the satellite needs to move at or slightly faster. Above our planet there is a conditional lower limit possible location of the satellite (passes at an altitude of 300 km). A closer placement will lead to a fairly rapid deceleration of the device in atmospheric conditions.
Initially, only launch vehicles could deliver artificial Earth satellites into orbit. Physics, however, does not stand still, and today new methods are being developed. Thus, one of the frequently used Lately methods - launching from another satellite. There are plans to use other options.
The orbits of spacecraft revolving around the Earth can lie on different heights. Naturally, the time required for one lap also depends on this. Satellites, whose orbital period is equal to a day, are placed on the so-called It is considered the most valuable, since the devices located on it appear motionless to an earthly observer, which means there is no need to create mechanisms for rotating antennas.
AMS (automatic interplanetary stations)
A huge amount of information about various objects solar system scientists receive it using spacecraft sent beyond geocentric orbit. AMS objects are planets, asteroids, comets, and even galaxies accessible for observation. The tasks posed to such devices require enormous knowledge and effort from engineers and researchers. AWS missions represent the embodiment of technological progress and are at the same time its stimulus.
Manned spacecraft
Devices created to deliver people to their intended destination and return them back are in no way inferior in technological terms to the described types. The Vostok-1, on which Yuri Gagarin made his flight, belongs to this type.
The most difficult task for the creators of a manned spacecraft - ensuring the safety of the crew during their return to Earth. Also significant part Such devices are an emergency rescue system, which may be necessary during the launch of a ship into space using a launch vehicle.
Spacecraft, like all astronautics, are constantly being improved. Recently, the media have often seen reports about the activities of the Rosetta probe and the Philae lander. They embody everything latest achievements in the field of space shipbuilding, calculation of vehicle motion, and so on. The landing of the Philae probe on the comet is considered an event comparable to Gagarin's flight. The most interesting thing is that this is not the crown of humanity’s capabilities. New discoveries and achievements still await us in terms of how to develop outer space, and buildings
Interplanetary spacecraft "Mars"
“Mars” is the name of Soviet interplanetary spacecraft launched to the planet Mars since 1962.
Mars 1 was launched on November 1, 1962; weight 893.5 kg, length 3.3 m, diameter 1.1 m. “Mars-1” had 2 hermetic compartments: an orbital one with the main onboard equipment that ensures flight to Mars; planetary with scientific instruments designed to study Mars during a close flyby. Flight objectives: exploration of outer space, checking radio links at interplanetary distances, photographing Mars. The last stage of the launch vehicle with the spacecraft was launched into an intermediate orbit artificial satellite Earth and provided the launch and the necessary increase in speed for the flight to Mars.
The active celestial orientation system had sensors for terrestrial, stellar and solar orientation, a system of actuators with control nozzles running on compressed gas, as well as gyroscopic devices and logical blocks. Most During the flight, orientation to the Sun was maintained to illuminate the solar panels. To correct the flight path, the spacecraft was equipped with a liquid rocket engine and a control system. For communication there was on-board radio equipment (frequencies 186, 936, 3750 and 6000 MHz), which provided measurement of flight parameters, reception of commands from the Earth, and transmission of telemetric information in communication sessions. The thermal control system maintained a stable temperature of 15-30°C. During the flight, 61 radio communication sessions were carried out from Mars-1, and more than 3,000 radio commands were transmitted on board. For trajectory measurements, in addition to radio equipment, a telescope with a diameter of 2.6 m was used from the Crimean Astrophysical Observatory. The Mars 1 flight provided new data about physical properties outer space between the orbits of the Earth and Mars (at a distance from the Sun of 1-1.24 AU), about the intensity of cosmic radiation, the strength of the magnetic fields of the Earth and the interplanetary medium, about the flows of ionized gas coming from the Sun, and about the distribution of meteoric matter (the spacecraft crossed 2 meteor shower). The last session took place on March 21, 1963, when the device was 106 million km away from the Earth. The approach to Mars occurred on June 19, 1963 (about 197 thousand km from Mars), after which Mars-1 entered a heliocentric orbit with perihelion ~148 million km and aphelion ~250 million km.
Mars 2 and Mars 3 were launched on May 19 and 28, 1971, and performed a joint flight and simultaneous exploration of Mars. The launch into the flight path to Mars was carried out from the intermediate orbit of an artificial Earth satellite by the last stages of the launch vehicle. The design and composition of the equipment of Mars-2 and Mars-3 differ significantly from Mars-1. The mass of “Mars-2” (“Mars-3”) is 4650 kg. Structurally, “Mars-2” and “Mars-3” are similar, they have an orbital compartment and a descent module. The main devices of the orbital compartment: instrument compartment, propulsion system tank block, corrective rocket engine with automation units, solar panels, antenna-feeder devices and radiators of the thermal control system. The descent vehicle is equipped with systems and devices that ensure the separation of the vehicle from the orbital compartment, its transition to a trajectory of approach to the planet, braking, descent in the atmosphere and a soft landing on the surface of Mars. The descent vehicle was equipped with an instrument-parachute container, an aerodynamic braking cone and a connecting frame on which the rocket engine was placed. Before the flight, the descent module was sterilized. Spacecraft had a number of systems to support flight. The control system, unlike Mars-1, additionally included: a gyroscopic stabilized platform, an on-board digital computer and a space autonomous navigation system. In addition to orientation towards the Sun, with sufficient great distance from the Earth (~30 million km), simultaneous orientation was carried out towards the Sun, the star Canopus and the Earth. The operation of the on-board radio complex for communication with the Earth was carried out in the decimeter and centimeter ranges, and the connection of the descent vehicle with the orbital compartment was in the meter range. The power source was 2 solar panels and a buffer battery. An autonomous chemical battery was installed on the descent module. The thermal control system is active, with circulation of gas filling the instrument compartment. The descent vehicle had screen-vacuum thermal insulation, a radiation heater with an adjustable surface and an electric heater, and a reusable propulsion system.
The orbital compartment contained scientific equipment intended for measurements in interplanetary space, as well as for studying the environs of Mars and the planet itself from the orbit of an artificial satellite; fluxgate magnetometer; an infrared radiometer to obtain a map of temperature distribution on the surface of Mars; infrared photometer for studying surface relief by radiation absorption carbon dioxide; optical device for determining water vapor content spectral method; visible photometer to study surface and atmospheric reflectivity; a device for determining the radio brightness temperature of a surface by radiation at a wavelength of 3.4 cm, determining its dielectric constant and the temperature of the surface layer at a depth of 30-50 cm; ultraviolet photometer to determine the density of the upper atmosphere of Mars, the content of atomic oxygen, hydrogen and argon in the atmosphere; cosmic ray particle counter; 
charged particle energy spectrometer; energy meter for electron and proton flow from 30 eV to 30 keV. On Mars-2 and Mars-3 there were 2 photo-television cameras with different focal lengths for photographing the surface of Mars, and on Mars-3 there was also Stereo equipment for conducting a joint Soviet-French experiment to study the radio emission of the Sun at the frequency 169 MHz. The descent module was equipped with equipment for measuring the temperature and pressure of the atmosphere, mass spectrometric determination of the chemical composition of the atmosphere, measuring wind speed, determining the chemical composition and physical and mechanical properties of the surface layer, as well as obtaining a panorama using TV cameras. The flight of the spacecraft to Mars lasted more than 6 months, 153 radio communication sessions were carried out with Mars-2, 159 radio communication sessions were carried out with Mars-3, and a large volume of scientific information. At a distance, the orbital compartment was installed, and the Mars-2 spacecraft moved into the orbit of the artificial satellite of Mars with an orbital period of 18 hours. On June 8, November 14 and December 2, 1971, corrections of the Mars-3 orbit were carried out. The separation of the descent module was carried out on December 2 at 12:14 Moscow time at a distance of 50 thousand km from Mars. After 15 minutes, when the distance between the orbital compartment and the descent vehicle was no more than 1 km, the device switched to the trajectory of meeting the planet. The descent module moved for 4.5 hours towards Mars and at 16 hours 44 minutes entered the planet’s atmosphere. The descent in the atmosphere to the surface lasted a little more than 3 minutes. The lander landed in the southern hemisphere of Mars in the area with coordinates 45° south. w. and 158° W. d. A pennant with the image was installed on board the device State emblem THE USSR. The orbital compartment of Mars-3, after separation of the descent module, moved along a trajectory passing at a distance of 1500 km from the surface of Mars. The braking propulsion system ensured its transition to the orbit of the Mars satellite with an orbital period of ~12 days. 19:00 On December 2, at 16:50:35, the transmission of a video signal from the surface of the planet began. The signal was received by the receiving devices of the orbital compartment and was transmitted to Earth in communication sessions on December 2-5.
For over 8 months, the orbital compartments of the spacecraft carried out a comprehensive program of exploration of Mars from the orbits of its satellites. During this time, the orbital compartment of Mars-2 made 362 revolutions, and Mars-3 - 20 revolutions around the planet. Studies of the properties of the surface and atmosphere of Mars based on the nature of radiation in the visible, infrared, ultraviolet spectral ranges and in the radio wave range made it possible to determine the temperature of the surface layer and establish its dependence on latitude and time of day; thermal anomalies were detected on the surface; thermal conductivity, thermal inertia, the dielectric constant and reflectivity of the soil; The temperature of the northern polar cap was measured (below -110 °C). Based on data on the absorption of infrared radiation by carbon dioxide, altitude profiles of the surface along the flight paths were obtained. The content of water vapor in various areas planets (about 5 thousand times less than in earth's atmosphere). Measurements of scattered ultraviolet radiation provided information about the structure of the Martian atmosphere (extent, composition, temperature). The pressure and temperature at the surface of the planet were determined by radio sounding. Based on changes in atmospheric transparency, data were obtained on the height of dust clouds (up to 10 km) and the size of dust particles (noted great content fine particles- about 1 micron). The photographs made it possible to clarify the optical compression of the planet, construct relief profiles based on the image of the edge of the disk and obtain color images of Mars, detect atmospheric glow 200 km beyond the terminator line, color changes near the terminator, and trace the layered structure of the Martian atmosphere.
Mars 4, Mars 5, Mars 6 and Mars 7 were launched on July 21, July 25, August 5 and 9, 1973. For the first time, four spacecraft simultaneously flew along an interplanetary route. "Mars-4" and "Mars-5" were intended to explore Mars from the orbit of an artificial satellite of Mars; "Mars-6" and "Mars-7" included descent modules. The spacecraft was launched onto the flight path to Mars from the intermediate orbit of an artificial Earth satellite. Radio communication sessions were regularly conducted along the flight route from the spacecraft to measure motion parameters, monitor the state of on-board systems and transmit scientific information. In addition to Soviet scientific equipment, French instruments were installed on board the Mars-6 and Mars-7 stations, intended for joint Soviet-French experiments on the study of solar radio emission (Stereo equipment), on the study of solar plasma and cosmic rays . To ensure the launch of the spacecraft to the calculated point of circumplanetary space during the flight, corrections were made to the trajectory of their movement. “Mars-4” and “Mars-5”, having covered a path of ~460 million km, reached the outskirts of Mars on February 10 and 12, 1974. Due to the fact that the braking propulsion system did not turn on, the Mars-4 spacecraft passed near the planet at a distance of 2200 km from its surface.
At the same time, photographs of Mars were obtained using a phototelevision device. On February 12, 1974, the corrective braking propulsion system (KTDU-425A) was turned on on the Mars-5 spacecraft, and as a result of the maneuver, the device entered the orbit of the artificial satellite of Mars. The Mars-6 and Mars-7 spacecraft reached the vicinity of the planet Mars on March 12 and March 9, 1974, respectively. When approaching the planet, the Mars-6 spacecraft autonomously, using the on-board celestial navigation system, carried out the final correction of its movement, and the descent module separated from the spacecraft. By turning on the propulsion system, the descent vehicle was transferred to the trajectory of the meeting with Mars. The descent vehicle entered the Martian atmosphere and began aerodynamic braking. When a given overload was reached, the aerodynamic cone was dropped and the parachute system was put into operation. Information from the descent module during its descent was received by the Mars-6 spacecraft, which continued to move in a heliocentric orbit with a minimum distance from the surface of Mars of ~1600 km, and was relayed to Earth. In order to study atmospheric parameters, instruments for measuring pressure, temperature, chemical composition and overload sensors were installed on the descent vehicle. The descent module of the Mars-6 spacecraft reached the surface of the planet in the area with coordinates 24° S. w. and 25° W. d. The descent module of the Mars-7 spacecraft (after separation from the station) could not be transferred to the trajectory of the meeting with Mars, and it passed near the planet at a distance of 1300 km from its surface.
The launches of the Mars series spacecraft were carried out by the Molniya launch vehicle (Mars-1) and the Proton launch vehicle with an additional 4th stage (Mars-2 - Mars-7).
1. Concept and features of the descent capsule
1.1 Purpose and layout
1.2 Descent from orbit
2. SK design
2.1 Housing
2.2 Thermal protection coating
List of used literature
The descent capsule (DC) of a spacecraft (SC) is designed for the rapid delivery of special information from orbit to Earth. Two descent capsules are installed on the spacecraft (Fig. 1).
Picture 1.
The SC is a container for an information carrier, connected to the film-stretch cycle of the spacecraft and equipped with a complex of systems and devices that ensure the safety of information, descent from orbit, soft landing and detection of the SC during descent and after landing.
Main characteristics of the insurance company
Weight of the assembled vehicle - 260 kg
Outer diameter of SC - 0.7 m
The maximum size of the assembled SC is 1.5 m
Spacecraft orbit altitude - 140 - 500 km
The inclination of the spacecraft's orbit is 50.5 - 81 degrees.
The SK body (Fig. 2) is made of aluminum alloy, has a shape close to a ball and consists of two parts: sealed and non-sealed. The sealed part contains: a special information carrier reel, a maintenance system thermal regime, a system for sealing the gap connecting the sealed part of the SC with the film-transfer path of the spacecraft, HF transmitters, a self-destruction system and other equipment. The unpressurized part houses the parachute system, dipole reflectors and the Peleng VHF container. Dipole reflectors, HF transmitters and the Peleng-UHF container provide detection of the SC at the end of the descent section and after landing.
From the outside, the SC body is protected from aerodynamic heating by a layer of heat-protective coating.
Two platforms 3, 4 with a pneumatic stabilization unit SK 5, a braking motor 6 and telemetric equipment 7 are installed on the descent capsule using tensioning straps (Fig. 2).
Before installation on the spacecraft, the lowered capsule is connected by three locks 9 of the separation system with the transition frame 8. After this, the frame is mated to the spacecraft body. The coincidence of the slots of the film-pulling paths of the spacecraft and the SC is ensured by two guide pins installed on the spacecraft body, and the tightness of the connection is ensured by a rubber gasket installed on the SC along the contour of the slot. From the outside, the SC is closed with screen-vacuum thermal insulation (SVTI) packages.
The shooting of the SC from the spacecraft body is carried out at the estimated time after sealing the gap in the film-pulling path, dropping the airborne materials packages and turning the spacecraft to a pitch angle that provides the optimal trajectory of the SC's descent to the landing area. At the command of the on-board digital computer of the spacecraft, locks 9 are activated (Fig. 2) and the SC, with the help of four spring pushers 10, is separated from the spacecraft body. The sequence of activation of the emergency control systems in the descent and landing sections is as follows (Fig. 3):
Spinning of the capsule relative to the X axis (Fig. 2) in order to maintain the required direction of the thrust vector of the brake motor during its operation, spinning is carried out by a pneumatic stabilization unit (PS);
Turning on the brake motor;
Quenching using PAS angular velocity SC rotation;
Shooting of the braking motor and PAS (if the tensioning straps fail to operate, the SC self-destructs after 128 s);
Removal of the parachute system cover, activation of the braking parachute and dipole reflectors, release of the frontal thermal protection (to reduce the weight of the vehicle);
Neutralization of means of self-destruction of the SK;
Shooting off the braking parachute and putting the main one into operation;
Pressurizing the cylinder of the "Peleng VHF" container and turning on the KB and VHF transmitters;
Activation of the soft landing engine by a signal from the isotope altimeter, landing;
Switching on at night based on a signal from the photo sensor of the light pulse beacon.
The SK body (Fig. 4) consists of the following main parts: the body of the central part 2, the bottom 3 and the cover of the parachute system I, made of aluminum alloy.
The body of the central part, together with the bottom, forms a sealed compartment designed to accommodate special information storage media and equipment. The connection of the body to the bottom is carried out using pins 6 using gaskets 4, 5 made of vacuum rubber.
The parachute system cover is connected to the body of the central part by means of pusher locks 9.
The body of the central part (Fig. 5) is a welded structure and consists of adapter I, shell 2, frames 3,4 and casing 5.
Adapter I is made of two parts, butt welded. On the end surface of the adapter there is a groove for rubber gasket 7, on the side surface there are bosses with blind threaded holes intended for installing a parachute system. Frame 3 serves to connect the body of the central part with the bottom using studs 6 and for fastening the instrument frame.
Frame 4 is the power part of the frame, is made of forgings and has a waffle structure. In the frame, on the side of the sealed part, on the bosses there are blind threaded holes intended for fastening devices, through holes “C” for installing pressurized connectors 9 and holes “F” for installing lock-pushers of the parachute system cover. In addition, the frame has a groove for the hose of the gap sealing system 8. The “K” lugs are designed for connecting the SC to the transition frame using locks II.
On the side of the parachute compartment, adapter I is closed by a casing 5, which is secured with screws 10.
There are four holes 12 on the body of the central part, which are used to install a mechanism for resetting the frontal thermal protection.
The bottom (Fig. 6) consists of frame I and spherical shell 2, butt welded together. The frame has two annular grooves for rubber gaskets, holes “A” for connecting the bottom to the body of the central part, three bosses “K” with blind threaded holes, intended for rigging work on the SK. To check the tightness of the SC, a threaded hole is made in the frame with a plug 6 installed in it. In the center of the shell 2, using screws 5, a fitting 3 is fixed, which is used for hydropneumatic testing of the SC at the manufacturer.
The parachute system cover (Fig. 7) consists of frame I and shell 2, butt welded. In the pole part of the cover there is a slot through which the adapter shank of the central part housing passes. On the outer surface of the cover, tubes 3 of the barorel block are installed and brackets 6 are welded, intended for fastening tear-off connectors 9. C inside The covers are welded to the shell with brackets 5, which serve to attach the drogue parachute. Jets 7 connect the cavity of the parachute compartment with the atmosphere.
Thermal protective coating (HPC) is intended to protect the metal body of the spacecraft and the equipment located in it from aerodynamic heating during descent from orbit.
Structurally, the SK TZP consists of three parts (Fig. 8): the TZP of the parachute system cover I, the TZP of the body of the central part 2 and the TZP of the bottom 3, the gaps between which are filled with Viksint sealant.
TZP cover I is an asbestos-textolite shell of variable thickness, bonded to a heat-insulating sublayer of TIM material. The sublayer is connected to the metal and asbestos laminate using glue. Inner surface the covers and the outer surface of the film-pulling tract adapter are covered with TIM material and foam plastic. The TZP covers contain:
Four holes for access to the fastening locks of the frontal heat protection, plugged with screw plugs 13;
Four holes for access to the pyrolocks securing the cover to the body of the central part of the SC, plugged with plugs 14;
Three pockets used for installing the SC on the transition frame and closed with linings 5;
Holes for tear-off electrical connectors, covered with covers.
The pads are installed on the sealant and secured with titanium screws. The free space in the places where the linings are installed is filled with TIM material, the outer surface of which is covered with a layer of asbestos fabric and a layer of sealant.
A foam cord is placed in the gap between the shank of the film-pulling tract and the end of the cutout of the TZP cover, onto which a layer of sealant is applied.
The TZP of the body of the central part 2 consists of two asbestos-textolite half-rings mounted on glue and connected by two pads II. The half rings and linings are attached to the body with titanium screws. On the TZP housing there are eight boards 4 intended for installing platforms.
TZP bottom 3 (frontal thermal protection) is a spherical asbestos-textolite shell of equal thickness. On the inside, a titanium ring is attached to the TZP with fiberglass screws, which serves to connect the TZP to the body of the central part using a reset mechanism. The gap between the bottom TZP and the metal is filled with sealant with adhesion to the TZP. On the inside, the bottom is covered with a layer of heat-insulating material TIM 5 mm thick.
2.3 Placement of equipment and units
The equipment is placed in the SC in such a way as to ensure ease of access to each device, the minimum length of the cable network, the required position of the center of mass of the SC and the required position of the device relative to the overload vector.