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HISTORY OF TECHNOLOGY, TECHNOLOGY, OBJECTS AROUND US
Space shuttles Shuttle and Buran. History of invention and production
Directory / The history of technology, technology, objects around us The Space Shuttle or simply the Shuttle (eng. Space Shuttle - "space shuttle") is an American reusable transport spacecraft. The shuttles were used as part of NASA's Space Transportation System (STS) government program. It was understood that the shuttles would "scurry like shuttles" between low Earth orbit and the Earth, delivering payloads in both directions.
The shuttle program has been developed by North American Rockwell on behalf of NASA since 1971. When creating the system, a number of technical solutions were used for the lunar modules of the Apollo program of the 1960s: experiments with solid propellant boosters, systems for their separation and obtaining fuel from an external tank. In total, five shuttles were built (two of them died in accidents) and one prototype. Flights into space were carried out from April 12, 1981 to July 21, 2011. While space launches were rare, the question of the cost of launch vehicles did not attract much attention to itself. But as space exploration progressed, it began to gain in importance. The cost of a launch vehicle in the total cost of launching a spacecraft varies. If the launch vehicle is serial and the spacecraft it launches is unique, the cost of the launch vehicle is about 10 percent of the total launch cost. If the spacecraft is serial and the carrier is unique - up to 40 percent or more. The high cost of space transportation is explained by the fact that the launch vehicle is used only once. Satellites and space stations operate in orbit or in interplanetary space, bringing a certain scientific or economic result, while rocket stages, which have a complex design and expensive equipment, burn up in dense layers of the atmosphere. Naturally, the question arose of reducing the cost of space launches by re-launching launch vehicles. There are many projects of such systems. One of them is a space plane. This is a winged machine that, like an air liner, would take off from the spaceport and, having delivered a payload to orbit (satellite or spacecraft), would return to Earth. But it is still impossible to create such an aircraft, mainly because of the necessary ratio of the masses of the payload and the total mass of the machine. Many other schemes of reusable aircraft turned out to be economically unprofitable or difficult to implement. Nevertheless, in the United States, they nevertheless headed for the creation of a reusable spacecraft. Many experts were against such an expensive project. But the Pentagon supported him. The development of the Space Shuttle system ("space shuttle") began in the United States in 1972. It was based on the concept of a reusable spacecraft designed to launch artificial satellites and other objects into near-Earth orbits. The Space Shuttle is a combination of a manned orbital stage, two solid rocket boosters and a large fuel tank located between these boosters. The Shuttle launches vertically with the help of two solid-propellant boosters (each 3,7 meters in diameter), as well as liquid-propellant rocket engines of the orbital stage, which are powered by fuel (liquid hydrogen and liquid oxygen) from a large fuel tank. Solid propellant boosters operate only in the initial part of the trajectory. Their running time is just over two minutes. At an altitude of 70-90 kilometers, the boosters are separated, parachuted into the water, into the ocean, and towed to the shore in order to use them again after reconditioning and recharging. When entering orbit, the fuel tank (8,5 meters in diameter and 47 meters long) is dropped and burned in the dense layers of the atmosphere.
The most complex element of the complex is the orbital stage. It resembles a rocket plane with a delta wing. In addition to the engines, it houses the cockpit and cargo compartment. The orbital stage deorbits like a conventional spacecraft and lands without thrust, only due to the lifting force of a small aspect ratio swept wing. The wing allows the orbital stage to perform some maneuver both in range and in course and, ultimately, to land on a special concrete strip. The landing speed of the stage is much higher than that of any fighter - about 350 kilometers per hour. The body of the orbital stage must withstand temperatures of 1600 degrees Celsius. The heat shield consists of 30922 silicate tiles glued to the fuselage and tightly fitted to each other. The Space Shuttle is a kind of compromise both technically and economically. The maximum payload delivered by the Shuttle into orbit is from 14,5 to 29,5 tons, and its launch mass is 2000 tons, that is, the payload is only 0,8-1,5 percent of the total mass of the refueled spacecraft. At the same time, this figure for a conventional rocket with the same payload is 2-4 percent. If we take as an indicator the ratio of the payload to the weight of the structure, excluding fuel, then the advantage in favor of a conventional rocket will increase even more. Such is the price for the opportunity to at least partially reuse spacecraft structures. One of the creators of spacecraft and stations, USSR pilot-cosmonaut, Professor K.P. Feoktistov assesses the economic efficiency of the Shuttle as follows: “Needless to say, it is not easy to create an economical transport system. Some experts are also confused about the idea of the Shuttle by the following. that in a year only one "aircraft", in order to justify its construction, must put into orbit about a thousand tons of different cargoes.On the other hand, there is a tendency to reduce the weight of spacecraft, increase the duration of their active life in orbit and, in general, to reduce the number launch vehicles by solving a set of tasks for each of them.
From the point of view of efficiency, the creation of a reusable transport ship of such a large carrying capacity is premature. It is much more profitable to supply orbital stations with the help of automatic transport vehicles of the Progress type. Today, the cost of one kilogram of cargo launched into space by the Shuttle is $25000, and by the Proton - $5000. Without the direct support of the Pentagon, the project could hardly have been brought to the stage of flight experiments. At the very beginning of the project, a committee was established at the headquarters of the US Air Force for the use of the Shuttle. A decision was made to build a shuttle launch pad at Vandenberg Air Force Base in California, from which military spacecraft are launched. Military customers planned to use the Shuttle to carry out a wide program of deploying reconnaissance satellites in space, radar detection and targeting systems for combat missiles, for manned reconnaissance flights, creating space command posts, orbital platforms with laser weapons, for "inspection" of aliens in orbit. space objects and their delivery to Earth. The Shuttle was also considered as one of the key links in the overall program for creating space laser weapons. So, already in the first flight, the crew of the Columbia spacecraft carried out a military task related to checking the reliability of the aiming device for laser weapons. A laser placed in orbit must be accurately aimed at missiles hundreds and thousands of kilometers away from it. Since the early 1980s, the US Air Force has been preparing a series of unclassified experiments in polar orbit to develop advanced equipment for tracking objects moving in air and airless space. The Challenger disaster on January 28, 1986 made adjustments to the further development of the US space programs. The Challenger went on its last flight, paralyzing the entire American space program. While the Shuttles were laid up, NASA's cooperation with the Department of Defense was called into question. The Air Force has effectively disbanded its astronaut group. The composition of the military-scientific mission, which received the name STS-39 and was transferred to Cape Canaveral, also changed. The dates for the next flight were repeatedly pushed back. The program resumed only in 1990. Since then, the Shuttles have regularly made space flights. They participated in the repair of the Hubble telescope, flights to the Mir station, and the construction of the ISS. By the time the Shuttle flights resumed in the USSR, a reusable ship was already ready, which in many respects surpassed the American one. On November 15, 1988, the new Energia launch vehicle launched the Buran reusable spacecraft into low Earth orbit. Having made two orbits around the Earth, guided by miracle machines, he landed beautifully on the concrete runway of Baikonur, like an Aeroflot airliner.
The Energia launch vehicle is the base rocket of an entire system of launch vehicles, formed by a combination of a different number of unified modular stages and capable of launching vehicles weighing from 10 to hundreds of tons into space! Its basis, the core, is the second step. Its height is 60 meters, diameter is about 8 meters. It has four liquid-propellant rocket engines powered by hydrogen (fuel) and oxygen (oxidizer). The thrust of each such engine at the Earth's surface is 1480 kN. Four blocks are docked in pairs around the second stage at its base, forming the first stage of the launch vehicle. Each block is equipped with the world's most powerful four-chamber engine RD-170 with a thrust of 7400 kN near the Earth. "Package" blocks of the first and second stages and forms a powerful, heavy launch vehicle with a launch weight of up to 2400 tons, carrying a payload of 100 tons. The total thrust of its engines at the beginning of the flight reaches 36000 kN. "Buran" has a great external resemblance to the American "Shuttle". The ship is built according to the scheme of a tailless aircraft with a delta wing of variable sweep, it has aerodynamic controls that work during landing after returning to the dense layers of the atmosphere - a rudder and elevons. He was able to make a controlled descent in the atmosphere with a lateral maneuver up to 2000 kilometers. The length of the Buran is 36,4 meters, the wingspan is about 24 meters, the height of the ship on the chassis is more than 16 meters. The launch weight of the ship is more than 100 tons, of which 14 tons are fuel. A sealed all-welded cabin for the crew and most of the equipment for flight as part of the rocket and space complex, autonomous flight in orbit, descent and landing is inserted into the nose compartment. Cabin volume - more than 70 cubic meters.
Buran in space When returning to the dense layers of the atmosphere, the most heat-stressed parts of the ship's surface heat up to 1600 degrees, while the heat reaching directly to the metal structure of the ship should not exceed 150 degrees. Therefore, "Buran" was distinguished by powerful thermal protection, which provides normal temperature conditions for the ship's structure during the passage of dense layers of the atmosphere during landing. The heat-shielding coating of more than 38 thousand tiles is made of special materials: quartz fiber, high-temperature organic fibers, partly carbon-based material. Ceramic armor has the ability to accumulate heat without passing it to the ship's hull. The total mass of this armor was about 9 tons. The length of the Buran cargo compartment is about 18 meters. Its vast cargo compartment could accommodate a payload weighing up to 30 tons. Large spacecraft could be placed there - large satellites, blocks of orbital stations. The landing weight of the ship is 82 tons. "Buran" was equipped with all the necessary systems and equipment for both automatic and manned flight. These are means of navigation and control, and radio engineering and television systems, and automatic devices for controlling the thermal regime, and a crew life support system, and much, much more. The main propulsion system, two groups of engines for maneuvering, are located at the end of the tail section and in front of the hull. The changes that made the Energia-Buran system different from the Space Shuttle system had the following results: in the Energia-Buran system, only the orbital ship itself was a reusable element in the first flight, while the first stage blocks and the central unit were lost during the launch process . On the other hand, a universal transport space system was created, which, unlike the Americans, made it possible to launch into space not only Buran, but also arbitrary heavy loads weighing up to 100 tons, while in the United States the shuttle is an integral part of the transport system and cargo limited to 29,5 tons, and due to the alignment of the orbiter, not a single flight with a full load was ever made. In the United States, there were plans to create a one-time only cargo system based on the Shuttle-C, but they were not implemented. Author: Musskiy S.A.
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