entranceHow the satellite works. How satellites are launched
The launch of the satellite into space marked a new era and became a breakthrough in the field of technology and astronautics. The need to create a satellite was identified at the beginning of the twentieth century. However, from the very beginning, many problems stood in the way of launching a satellite into outer space, over which the best engineers and scientists worked. These problems were associated with the need to create engines capable of working in the harshest conditions and, at the same time, they must be unusually powerful. The same problems were associated with the correct determination of the trajectory of the satellite.
So, Soviet scientists solved the tasks, and on October 4, 1957, an artificial satellite was successfully launched in the USSR, the movement of which was watched by the whole world. This event became a world breakthrough and marked a new stage, both in science in general and throughout the world.
Live broadcast of the Soyuz-Progress launch (mission to the ISS)
Satellite tasks
The tasks solved by the satellite launch can be defined as the following:
1. Study of the climate;
Everyone knows what impact climate has on agriculture and military infrastructure. Thanks to satellites, you can predict the appearance of destructive elements, avoid a large number of victims.
2. Study of meteorites;
In outer space is great amount meteorites weighing up to several thousand tons. Meteorites can be dangerous not only for satellites, spaceships, but also for people. If during the flight of a meteorite the friction force is small, then the unburned part is able to reach the Earth. The speed range of meteorites reaches from 1220 m / s to 61000 m / s.
3. Application of television broadcasting;
Currently, the role of television is great. In 1962, the first television broadcast was launched, thanks to which the world saw video footage for the first time across the Atlantic in a matter of minutes.
4. GPS system.
The GPS system plays a huge role in almost every area of our lives. GPS is classified into civil and military. It represents electromagnetic signals emitted in the radio wave part of the spectrum by an antenna installed on each of the satellites. Consists of 24 satellites, which are in orbit at an altitude of 20,200 km. The time of revolution around the Earth is 12 hours.
Telecommunication satellite "Arabsat-5B"
Soyuz launch
Launching satellites and putting them into orbit
To begin with, it is important to indicate the trajectory of the satellite's flight. At first glance, it seems that it is more logical to launch the rocket perpendicularly (along the shortest distance to the target), however, this type of launch turns out to be unprofitable, both from an engineering point of view and from an economic point of view. A satellite launched vertically is acted upon by the forces of gravity of the Earth, which significantly pull it away from the designated trajectory, and the thrust force becomes equal to the force of gravity of the Earth.
To avoid the fall of the satellite, first, it is launched vertically so that it can overcome the elastic layers of the atmosphere, such a flight continues for only 20 km. Then the satellite tilts with the help of the autopilot and moves horizontally towards the orbit.
In addition, the task of engineers is to calculate the flight trajectory in such a way that the speed spent on overcoming the atmospheric layers, as well as on the fuel consumption, was only a few percent of the characteristic speed.
It is also important in which direction to launch the satellite. When the rocket is launched in the direction of the Earth's rotation, there is an increase in speed, which depends on the location of the launch. For example, at the equator it is maximum and is 403 m / s.
The orbits of satellites are circular and elliptical. An elliptical orbit will appear if the rocket speed is higher than the circumferential speed. The point located in the closest position is called the perigee, and the most distant apogee.
The launch of a rocket with a satellite itself is carried out in several stages. When the engine of the first stage stops working, the angle of inclination of the launch vehicle will be 45 degrees, at an altitude of 58 km, then it is separated. The engines of the second stage are switched on, with an increase in the angle of inclination. Further, the second stage is separated at an altitude of 225 km. Then, by inertia, the rocket reaches an altitude of 480 km and finds itself at a point located at a distance of 1125 km from the start. Then the engines of the third stage start to work.
Return of the satellite to earth
The return of the satellite to Earth is accompanied by some braking problems. Braking can be done in two ways:
- Thanks to the resistance of the atmosphere. The speed of a satellite entering the upper atmosphere will decrease, but due to its aerodynamic shape, it ricochets back into space. After that, the satellite will decrease its speed and enter deeper into the atmosphere. This will be repeated several times. After reducing the speed, the satellite will descend using retractable wings.
- Automatic rocket engine. The rocket engine should be directed in the direction opposite to the movement of the artificial satellite. A plus this method is that the braking speed can be adjusted.
Conclusion
So, satellites have entered human life in just half a century. Their participation helps to explore new outer spaces. Satellite as a means of uninterrupted communication helps to make daily life of people. Paving the way into space, they help make our life what it is now.
What could be more beautiful than lighting the stars in the sky! We decided to light our own, the brightest. Shining brighter than Sirius, Vega and Altair, visible in all major cities of the Earth, made by our hands, it will prove that space can become the business of everyone - an engineer and artist, mathematician and historian, physicist and journalist.
About Us:
We are the community "Your Sector of Space". We believe that the sky overhead hides many unconquered peaks, and we dream of gradually exploring the endless expanses of space. We tell people about astronautics and show that in order to make space closer to every inhabitant of our planet, it is not necessary to belong to a large state or private corporation.
Our projects:
Within the community, there is a popular science lecture hall where you can listen to former and current developers of rocket technology, visit the most interesting space enterprises and museums of cosmonautics and just chat with like-minded people. July 12 "Your Sector of Space" launched a series of lectures "Space from sea to sea", so that not only residents of Moscow and St. Petersburg, but also Siberians and Kamchadals can learn about other planets, stars and spacecraft.
In the near future, we plan to create a cosmonautics section for schoolchildren and students on the basis of the lecture hall, in which young people can work on real space projects, for example, on a spacecraft with a guaranteed launch into a near-earth orbit, on scientific equipment intended for installation on a spacecraft, or over the processing of data received from space.
About the satellite:
To make the satellite a guiding star for all those who want to touch the secrets of space, we will install a reflector of sunlight on the device, which will send giant sunbeams to Earth. We want to make the reflector quite large so that the reflections of the Sun on Earth are also large, so we make the reflector drop down, reminiscent of a car's airbag.
Before flying on a rocket, the reflector will be neatly folded inside the satellite, and after entering orbit it will straighten out, filling with gas. As in a car, our "pillow" is made of a thin film. This film is similar to the one used to wrap flowers, only it is more heat resistant.
The deployment system is responsible for storing the gas and supplying it to the reflector. It is important to make sure that the fueled satellite is safe for people when working with it on the ground and for other satellites during their joint flight on a rocket. It is for the sake of safety that we do not use high pressures and aggressive chemicals to create the required pressure in the reflector.
All satellite systems are powered by the power supply system. In our case, it is built on the basis of conventional lithium polymer batteries, similar to those used in cell phones... The satellite will need electricity for a very short time, so there will be no solar panels on board.
We plan to finish the apparatus by the end of this summer. In the fall of 2014, tests are planned in the stratosphere with the disclosure of the reflector in free fall and at reduced pressure, that is, in conditions as close as possible to space. After that, we will analyze the test results, finalize the satellite design, and by the end of 2014 we will be ready to launch it into orbit. Now we are considering various options for sending our satellite into space, including non-commercial ones.
We have already done a lot - we have carried out all the calculations and a series of experiments with materials necessary for the design of the satellite, we are working on the technological layout of the satellite reflector and the elements of a large reflector, and we are preparing the apparatus itself. But in order to send our star into the sky, we need your help! The collected money will be enough for us to pay for the experimental launch of the device into the stratosphere and understand how our satellite will behave in outer space. Denis Efremov's project "Near Space" will help us in this.
If we collect more money than we need for stratospheric tests, we will conduct a number of other experiments - and, of course, we will invite everyone who helped us to look at them.
Extended project goals:
400,000 rubles is the minimum task. This is exactly how much we need to collect in order to conduct stratospheric tests of the satellite.
1,400,000 rubles- having mastered such an amount together with you, we will be able to carry out additional more precise experiments. For example, thermal vacuum tests of the satellite deployment system in conditions as close as possible to space, or tests on a vibration stand, which will give us an idea of how the satellite will behave during a flight on a rocket.
2 600 000
rubles- the amount required for a commercial launch into space. If we together with you can accomplish such a feat, then immediately after the tests our satellite will go into orbit.
Support the project and become the one who was able not only to get a star from the sky, but to light it up! Tell others about the satellite - together we can prove that space is closer than it seems.
Our contacts:
How to illegally launch satellites March 11th, 2018
In January 2018, the first successful illegal launch of a satellite into space, or rather four small experimental orbiting drones, took place for the first time in the history of mankind.
The illegal launch of satellites called SpaceBee-1, 2, 3 and 4 into space was managed by the American company Swarm Technologies, which agreed with Indian experts that they would additionally load four book-sized drones onto the Polar Satellite Launch Vehicle along with three dozen other satellites.
Back in the 2000s, the Indian Space Research Organization (ISRO) set out to launch hundreds of satellites into orbit for the needs of the state and business, and achieved noticeable success in this direction, so it was not difficult to "grab" several commercial devices for them. ...
According to open data, the last successful launch of a PSLV rocket with satellites in India, the USA, Canada, Finland, France and South Korea took place on January 12, 2018.
Only after the Swarm Technologies satellites were in space, US regulatory authorities raised the alarm: it is difficult to track small objects in orbit normally, but at the same time they pose a mortal danger to any device or ship that may collide.
The legal conflict with Swarm Technologies is that the responsibility for its actions in space is not borne by India, but by the United States, where this company is registered. The scientific community is especially indignant about this, which demands to understand how a group of private individuals, in secret from the state, put their satellites into orbit at a time when even the Pentagon is obliged to strictly report on such things, with rare exceptions.
According to another IEEE Spectrum online publication, SpaceBee-1, 2, 3 and 4 are designed for “two-way satellite communications and data transmission from the USA ”. It is known about Swarm Technologies itself that it "grew" out of a well-known startup Silicon Valley in California.
The company was founded two years ago by Canadian aerospace engineer, former NASA and Google employee Sarah Spangelo, and independent developer Benjamin Longmeyer, a professor at the University of Michigan, who sold his previous company, Aether Industries, to Apple.
The company has only five employees, and this entire team is working on a system that will allow businesses to use the power of satellite Internet to create a unified network of ships, trucks, cars, agricultural equipment and anything else that can be assigned an IP address. The Internet to all these devices anywhere in the world should be distributed by SpaceBee-1, 2, 3 and 4, as well as their future counterparts.
Presumably, Swarm Technologies needed its own satellites in order to show potential investors how cheap it can be. Satellite Internet with the right approach to business in the framework of the concept of the "Internet of Things".
All would be fine, but in December 2017, the US Federal Communications Commission
On April 12, 1961, for the first time in history, the Soviet Union launched a manned ship on board which was Yuri Gagarin. Today we will show how the second Kazakh telecommunications satellite KazSat-2 (KazSat-2) was launched from the Baikonur cosmodrome using the Proton-M launch vehicle. How was the spacecraft launched into orbit, what state is it in, how and where is it controlled? We will learn about this in this photo essay.
12th July 2011. The heaviest Russian space rocket "Proton-M" with the Kazakh communications satellite No. 2 and the American SES-3 (OS-2) are taken to the launch site. Proton-M is launched only from the Baikonur cosmodrome. It is here that the necessary infrastructure exists to service this complex rocket and space system. The Russian side, namely the manufacturer of the device, the Khrunichev Space Center, guarantees that KazSat-2 will serve for at least 12 years.
Since the signing of the agreement on the creation of the satellite, the project has been revised several times, and the launch itself has been postponed at least three times. As a result, "KazSat-2" received a fundamentally new element base and a new control algorithm. But most importantly, the satellite was equipped with the latest and very reliable navigation devices, manufactured by the French concern ASTRIUM.
This is a gyroscopic angular velocity vector meter and astro sensors. With the help of astro sensors, the satellite orients itself in space by the stars. It was the failure of navigation equipment that led to the fact that the first "KazSat" was actually lost in 2008, which almost caused an international scandal.
The path of the rocket with the power supply and temperature control systems of the warhead connected to it, where the Breeze-M upper stage and the satellites are located, takes about 3 hours. The speed of the special train is 5-7 kilometers per hour, the train is serviced by a team of specially trained drivers.
Another group of cosmodrome security personnel inspects the railway tracks. The slightest non-rated load can damage the rocket. Unlike its predecessor, KazSat has become more energy-intensive.
The number of transmitters has increased to 16. There were 12 of them on KazSat-1, and the total transponder power was increased to 4 and a half kilowatts. This will allow you to pump an order of magnitude more data of all kinds. All these changes affected the cost of the device. It amounted to $ 115 million. The first apparatus cost Kazakhstan 65 million.
The inhabitants of the local steppe calmly watch everything that happens. Desert ships)
The dimensions and capabilities of this rocket are truly mind-boggling. Its length is 58.2 meters, its weight is 705 tons. At the start, the thrust of 6 engines of the first stage of the launch vehicle is about 1,000 tons. This makes it possible to launch objects weighing up to 25 tons into a reference near-earth orbit, and up to 5 tons into a high geostationary orbit (30 thousand km from the Earth's surface). Therefore, Proton-M is irreplaceable when it comes to launching telecommunication satellites.
- There are simply no two identical spacecraft, because each spacecraft is a completely new technology. In a short period, it happens that completely new elements have to be changed. In "KazSat-2" those new advanced technologies were applied, which at that time already existed. Part of the equipment of European production was delivered, in the part where we had refusals for "KazSat-1". I think that the equipment that we currently have at KazSat-2 should show good results. It has a fairly good flying history.
At the cosmodrome there are currently 4 launch sites for the Proton carrier rocket. However, only 3 of them, at sites No. 81 and No. 200, are in working order. Previously, only the military was engaged in launches of this rocket due to the fact that working with toxic fuel required hard command manuals. Today the complex is demilitarized, although there are a lot of former military personnel in the combat crews who have removed their shoulder straps.
The orbital position of the second KazSat has become much more convenient for work. It is 86 and a half degrees east longitude. The coverage area includes the entire territory of Kazakhstan, part of Central Asia and Russia.
The sunsets at the Baikonur cosmodrome are exclusively technological! The massive structure just to the right of the center of the picture is the “Proton-M” with a service truss connected to it. From the moment the rocket was taken out to the launch position of the site No. 200, and until the moment of launch, 4 days pass. All this time, preparation and testing of the Proton-M systems is being carried out. Approximately 12 hours before the start, a meeting of the state commission is held, which gives permission to refuel the rocket. Refueling starts 6 hours before the start. From this moment on, all operations become irreversible.
What benefit does our country get from having its own communications satellite? First of all, it is a solution to the problem information support Kazakhstan. Your satellite will help expand the spectrum information services for the entire population of the country. This is a service of electronic government, the Internet, mobile communications... The most important thing is that the Kazakh satellite will allow to partially refuse the services of foreign telecommunication companies, which provide our operator with relay services. We are talking about tens of millions of dollars, which will now not go abroad, but go to the country's budget.
Victor Lefter, President of the Republican Center for Space Communications:
- Kazakhstan has a fairly large territory compared to other countries. And you need to understand that in every locality, in every village, rural school we will not be able to provide those communication services that are limited by means of cable and other systems. The spacecraft solves this problem. The entire territory is practically closed. Moreover, not only the territory of Kazakhstan, but also part of the territory of neighboring states. And the satellite is a stable communication capability
Various modifications of the Proton launch vehicle have been in operation since 1967. Its chief designer was Academician Vladimir Chelomey and his design bureau (currently - the design bureau "Salyut", a branch of the Khrunichev State Research and Production Space Center). We can safely say that all the impressive Soviet projects for the development of near-Earth space and the study of objects Solar system would be impracticable without this missile. In addition, Proton is distinguished by a very high reliability for equipment of this level: during its entire operation, 370 launches were made, of which 44 were unsuccessful.
The only and main drawback of “Proton” is its extremely toxic fuel components: unsymmetrical dimethylhydrazine (UDMH), or as it is also called “heptyl” and nitrogen tetroxide (“amyl”). In the places where the first stage fell (these are the territories in the area of the city of Dzhezkazgan), environmental pollution occurs, which requires expensive cleaning operations.
The situation was seriously aggravated in the early 2000s, when there were three successive crashes of the launch vehicle. This caused the extreme discontent of the Kazakh authorities, who demanded large compensation from the Russian side. Since 2001, the old modifications of the launch vehicle have been replaced with the modernized Proton-M. It stands digital system control, as well as a system for bleeding unburned fuel residues in the upper layers of the ionosphere.
Thus, it was possible to significantly reduce the damage to the environment. In addition, a project has been developed, but still remains on paper, a project of the environmentally friendly Angara launch vehicle, which uses kerosene and oxygen as fuel components, and which is to gradually replace Proton-M. By the way, the "Angara" launch vehicle complex at Baikonur will be called "Baiterek" (translated from Kazakh "Topol".)
It was the reliability of the rocket that at one time attracted the Americans. In the 90s, a joint venture ILS was created, which positioned the missile in the American telecommunications systems market. Today, most American civilian communications satellites are launched by Proton-M from a cosmodrome in the Kazakh steppe. The American SES-3 (owned by SES WORLD SKIES), which is at the head of the rocket along with the Kazakh KazSat-2, is one of many launched from Baikonur.
In addition to the Russian and American flags, the rocket carries the Kazakh and the emblem of the Republican Center for Space Communications - the organization that today owns and operates the satellite.
July 16, 2011 5 hours 16 minutes and 10 seconds in the morning. The climax. Fortunately, everything is going well.
3 months after launch. Young specialists are the leading engineer of the satellite control department Bekbolot Azaev, as well as his colleagues engineers Rimma Kozhevnikova and Asylbek Abdrakhmanov. These guys are running KazSat-2.
Akmola region. The small, and until 2006, unremarkable regional center Akkol became widely known 5 years ago, when the first MCC in the country was built here - the control center for the flights of orbiting satellites. October is cold, windy and rainy here, but right now is the hottest time for those people who must give the KazSat-2 satellite the status of a full-fledged and important segment of Kazakhstan's telecommunications infrastructure.
After the loss of the first satellite in 2008, a major modernization was carried out at the Akkol Space Communication Center. It already allows you to control two devices at once.
Baurzhan Kudabaev, Vice President of the Republican Center for Space Communications:
- A special software, new equipment supplied. In front of you is the counter of the command and measurement system. This is the delivery of the American company Vertex, as was the case at KazSat-1, but already of a new modification, an improved version. The developments of the Russian Space Systems company were applied. Those. these are all developments of today. New programs, equipment, element base. All this improves the work with our spacecraft.
Darkhan Maral, Head of the Flight Control Center at the workplace. In 2011, young specialists, graduates of Russian and Kazakh universities came to the Center. They have already been taught to work, and according to the leadership of the RCKS, there are no problems with staffing. In 2008, the situation was much sadder. After the loss of the first satellite, a significant part of the highly educated people left the center.
October 2011 was another culmination moment in the work on the Kazakh satellite. Its flight design tests were completed, and the so-called crediting tests began. Those. it was like an exam for the manufacturer on the functionality of the satellite. Everything happened in the following way. A television signal was raised at KazSat-2.
Then several groups of specialists went to different regions of Kazakhstan and measured the parameters of this signal, i.e. how correctly the signal is relayed by the satellite. There were no comments, and in the end a special commission adopted an act on the transfer of the satellite to the Kazakh side. From that moment on, Kazakhstani specialists are engaged in the operation of the apparatus.
Until the end of November 2011, a large group of Russian specialists worked at the Akkol space center. They represented subcontractors for the KazSat-2 project. These are the leading companies in the Russian space industry: Center im. Khrunichev, who designed and built the satellite, the Mars design bureau (it specializes in the navigation of orbiting satellites), and the Russian Space Systems Corporation, which develops software.
The whole system is divided into two components. This is, in fact, the satellite itself and the ground control infrastructure. According to the technology, the contractor must first demonstrate the performance of the system - this is the installation of equipment, its debugging, demonstration functionality... After all the procedures - training of Kazakhstani specialists.
The space communications center in Akkola is one of the few places in our country where a favorable electromagnetic environment has developed. There are no radiation sources for many tens of kilometers around. They can interfere and interfere with satellite control. 10 large parabolic antennas point into the sky at a single point. There, at a great distance from the Earth's surface - it is more than 36 thousand kilometers, a small man-made object hangs - the Kazakh communications satellite "KazSat-2".
Most modern communication satellites are geostationary. Those. their orbit is constructed in such a way that it seems to hover over one geographic point, and the rotation of the Earth has practically no effect on this stable position. This allows using an onboard repeater to pump large amounts of information, to confidently receive this information in the coverage area on Earth.
Another interesting detail. According to international rules, the permissible deviation of a satellite from a stationary point can be a maximum of half a degree. For MCC specialists - keep the device in given parameters- jewelry work that requires the highest qualifications of ballistics specialists. The center will employ 69 people, of whom 36 are technical specialists.
This is the main control panel. There is a large monitor on the wall, where all telemetry flows; on a semicircular table, there are several computers and telephones. Everything seems to be very simple ...
Victor Lefter, President of the Republican Center for Space Communications:
- We will expand the Kazakh flotilla to 3, 4, and possibly even up to 5 satellites. Those. so that there is a constant replacement of devices, there is a reserve, and so that our operators do not feel such an urgent need to use products from other countries. So that we can be provided with our reserves. "
At present, the satellite control reservation is carried out from Moscow, where the space center is located. Khrunichev. However, the Republican Center for Space Communications intends to reserve a flight from Kazakhstani territory. For this, a second MCC is currently under construction. It will be located 30 kilometers north of Almaty.
The plans of the National Space Agency of Kazakhstan include the forthcoming launch of the third satellite “KazSat-3” in 2013. The contract for its development and production was signed in 2011 in France, at the aerospace show in Le Bourget. The satellite for Kazakhstan is being built by the Scientific and Production Association named after Academician Reshetnev, which is located in the Russian city of Krasnoyarsk.
Management department operator interface. This is how it looks now.
In the video you can see how this one was launched.
We continue our series of articles "Everything about everything". This time, let's talk about satellites.
Not so long ago, satellites were exotic and super-secret devices. They were mainly used for military purposes, navigation and espionage. Now they are an integral part of modern life. We can see them in weather forecasting, television, and even ordinary phone calls... Satellites also often play a supporting role in some areas:
- Some newspapers and magazines are fast because they send materials to different printers via satellites to speed up local distribution.
- Before transmitting the signal over the wires to users cable TV, service providers use satellites to transmit the signal.
- Recently, geolocation opportunities provided by GPS systems and GLONASS. With the help of them, we can get to the required month faster and more accurately.
- The goods we buy are delivered by the supplier's manufacturers more efficiently thanks to logistics using geolocation using GPS and GLONASS.
- Beacons from crashed aircraft and ships in distress send signals to rescue teams via satellite.
What is Sputnik?
A satellite in general is an object that orbits a planet in a circular or elliptical orbit. For example, the Moon is a natural natural satellite of the Earth, but there are many more man-made (artificial) satellites, which are usually closer to the Earth.The path followed by a satellite is called an orbit. The point of the orbit farthest from the Earth is called the apogee, the closest is the perigee.
Artificial satellites are not mass-produced. Most of the satellites have been specially manufactured to fulfill their intended functions. The exception is GPS / GLONASS satellites (of which there are about 20 copies for each of the systems) and satellites of the Iridium system (of which there are more than 60 copies, they are used for voice communication).
There are also about 23,000 objects that are space debris. These objects are large enough to be detected by radar. They either accidentally ended up in orbit, or they have exhausted their usefulness. The exact number depends on who is counting. Payload that fell into the wrong orbit, satellites that have run out of batteries and also the remnants of rocket boosters - all this is space debris. For example, this online satellite catalog contains about 26,000 objects.
While any object orbiting the earth can actually be called a satellite, the term "satellite" is commonly used to describe a useful object placed in orbit for some important purposes. We often hear about weather satellites, communications satellites, and scientific satellites.
Whose satellite was the first to orbit the Earth?
In general, the Moon is rightfully considered the very first satellite of the Earth :)
For our common joy, the first artificial Earth satellite was Sputnik 1, launched by The Soviet Union October 4, 1957. Hurray, comrades!
However, due to the strictest secrecy that existed at that time, there are no publicly available photographs of that famous launch. Sputnik 1 was 23-inches (58 centimeters) long, weighed 184 pounds (83 kilograms) and was shaped like a metal ball. However, this was an important achievement for that time. The content of the satellite seems scarce by modern standards:
- Thermometer
- Battery
- Radio transmitter - changed the tone of its sounds according to thermometer readings
- Nitrogen - created pressure inside the satellite
After 92 days, gravity did its job and Sputnik 1 burned up in the Earth's atmosphere. Thirty days after the launch of Sputnik 1, Laika the dog flew on a half-ton airborne satellite. This satellite burned up in the atmosphere in April 1958.
Sputnik-1 is good example how simple a satellite can be. As we will see later, modern satellites are much more complex, but the basic idea is simple.
How are satellites launched into orbit?
All modern satellites enter orbit using rockets. Some were delivered into orbit in the shuttle cargo bay. Several countries and even commercial companies have the ability to launch satellites into orbit, and now it is not unusual to deliver a satellite weighing several tons into orbit.
For most scheduled launches, the rocket is generally vertical upward. This allows it to pass through the dense layers of the atmosphere quickly and with minimal cost fuel.
After the missile is launched vertically upward, the missile guidance system uses an inertial guidance system to guide the missile's nozzles and guides it to its intended trajectory. Most of the time, the rocket is heading east because the Earth itself rotates east, which allows the rocket to add "free" acceleration. The strength of this "free" acceleration depends on the speed of rotation of the Earth at the launch site. The greatest acceleration is at the equator, where the distance around the Earth is greatest, and, consequently, the speed of rotation too.
How big is the acceleration at equatorial launch? For a rough estimate, we can calculate the length of the Earth's equator by multiplying its diameter by pi (3.141592654 ...). The diameter of the earth is approximately 12,753 kilometers. Multiplying by pi we get a circumference of about 40,065 kilometers. To traverse the entire circumference in 24 hours, a point on the Earth's surface must move at a speed of 1,669 km / h. The launch from Baikonur in Kazakhstan does not give such a large acceleration from the rotation of the Earth. The Earth's rotation speed in the Baikonur region is about 1,134 km / h, and in the Plesetsk region, in general, 760 km / h. Thus, launching from the equator gives more "free" acceleration. In general, the Earth does not quite have the shape of a sphere - it is flattened. Therefore, our estimate of the Earth's circumference is somewhat inaccurate.
But wait, you say, if rockets are capable of reaching speeds of thousands of kilometers per hour, then what will give a small increase? The answer is that the rockets, along with the fuel and payload, are very heavy. For example, according to Wikipedia, the proton booster has a launch mass of 705 tons. To accelerate such a mass even up to 1,134 km / h requires a huge amount of energy, and therefore a large amount of fuel. Therefore, launching from the equator provides tangible benefits.
When the rocket reaches very thin air at an altitude of about 193 kilometers, the rocket control system turns on small engines sufficient to rotate the rocket to a horizontal position. Then the satellite is separated from the rocket. The rocket then turns on the engines again to provide some separation between the rocket and the satellite.
Inertial guidance system
The rocket must be controlled very accurately in order to launch the satellite into the required orbit, and mistakes in this matter are very expensive (remember the failures of Roscosmos with the GLONASS satellites or the Phobos-Grunt probe, which ended up in the wrong orbit in which they should have been). The inertial guidance systems inside the missiles make such control possible. Such a system determines the exact position of the rocket and its direction by measuring the acceleration of the rocket using gyroscopes and accelerometers. Located in the gimbal, the gyroscope axes always point in the same direction. In addition, the gyro platform contains accelerometers that measure acceleration in three different axes. If the control system knows the initial position of the rocket at the moment of launch and acceleration at the moment of flight, it will be able to calculate the position of the rocket and orientation in space.Orbital speed and altitude
The rocket must accelerate to a speed of at least 40 320 km / h (11.2 km / s) in order to completely escape from Earth's gravity and go into space. This speed is called the second cosmic speed and it is different for different celestial bodies.
The second cosmic speed of the earth is much greater than the speed required to place the satellites in orbit. Satellites do not need to get out of the Earth's gravity, they need to balance against it. Orbital speed is the speed required to balance the gravitational pull and inertia of the satellite. On average, this speed is 27,359 km / h at an altitude of about 242 kilometers. Without gravity, the satellite's inertia will push it out into space. Although even if gravity is present, then too high a satellite speed will take it out of Earth's orbit into open space. On the other hand, if the satellite moves slowly, then under the influence of gravity, it will fall back to Earth. If the satellite has a certain correct speed, then gravity will be balanced by the inertia of the satellite, the gravity of the Earth will be sufficient for the satellite to move in a circular or elliptical orbit, and not fly into space in a straight line.
The satellite's orbital speed depends on how high the satellite is. The closer to the Earth, the greater the required speed. At an altitude of 200 kilometers, the required orbital speed is about 27,400 km / h. To maintain an orbit of 35,786 km, the satellite must orbit at a speed of about 11,300 km / h. This orbital speed will allow the satellite to make one revolution around the Earth in 24 hours. Since the Earth itself rotates at a speed of 24 hours, a satellite at an altitude of 35,786 km will remain strictly above the same point on the Earth's surface. This orbit is called "geostationary". Geostationary orbits are ideal for weather and communications satellites.
The Moon has an "altitude" of 384,400 kilometers relative to the Earth, and its orbital speed is 3,700 km / h. It completes a complete revolution in its orbit in 27.322 days. Note that its orbital speed is lower because it is farther than artificial satellites.
In general, the higher the orbit, the longer the satellite can be in orbit. At low altitudes, the satellite enters the atmosphere, which creates friction. Friction takes away part of the satellite's motion energy, and it gets into denser layers and, falling to the Earth, burns up in the atmosphere. At high altitudes, where there is almost a vacuum, friction does not arise and the satellite can remain in orbit for centuries (take the Moon, for example).
Satellites usually have an elliptical orbit first. Ground control stations use the satellite's small jet engines to correct the orbit. The goal is to make the orbit as circular as possible. Turning on the jet engine at the apogee of the orbit (the most distant point), and applying force in the direction of flight, moves the perigee further from the Earth. As a result, the orbit approaches circular in shape.
To be continued…