Rocket launcher "Energia" (11К25)

The Energia launcher is the first Soviet rocket using cryogenized fuel (hydrogen), and the most powerful rocket of the country, the total capacity of the engines is 170 million horse power.

The rocket consists of 2 stages, first is made of 4 engines (block A) with oxygenated kerosene laid out on the side of the central block. The second stage is the central block (Ц block) which is propelled with a mixture of hydrogen and liquid oxygen (propellant), the payload is laid out asymmetrically on it. Thanks to its general-purpose configuration Energia is able to put into low orbit with the Buran shuttle or of another structures (Polyus...) large-sized loads and a mass going up to 100 t. The major difference between Energia and the American launcher lie in the fact that the central block is not a fuel tank for the shuttle's engines but a entire stage and thus the payload does not have any role in orbiting. This is why the American launcher cannot fly without its shuttle and its powerful SSME engines.

The engines

The starting mass of the rocket reach 2400 t. Each block of the first stage supplies a ЖРД РД-170 engine, composed of 4 nozzles, out of liquid oxygen and hydrocarbonated fuel. The thrust of the engine of the first stage makes nearly 740 t on the ground and 806 t in vacuum. The second stage is driven by 4 ЖРД РД-0120 engines, whose thrust are 148 t each one on the ground and 200 t in vacuum, functioning with a mixture of oxygen and liquid hydrogen (oxygen is cooled at -186°C and hydrogen at -255°C). The total thrust during the flight is 3550 t. Engines ЖРД РД-170 especially worked out for Energia and used for the first time on "Zenith" ("Зенит") are extremely powerful and do not have an abroad equivalent.
All the engines are built according to a sparing mode, a closed circulation of gases, the gases from in the turbine are re-injected in the main combustion chamber.
The engines are started quasi simultaneously which avoids the problems related to lighting in vacuum and increases the safety of launching.
For the displacement of the rocket, the engines are operated in a precise way (less than 1% of error in the range of displacements), a hydraulic system controls the jacks of the nozzle. These jacks develop a pressure of 50 t for the engines of the first stage and 30 t for those of the second.

РД-170	РД-0120	РД-0120

1st stage

The blocks of the first stage are ejected in couple from the launcher after having consumed their fuel at 140 s from the ignition, an altitude of 53 km and a speed of 1.8 km/s. Then 15-25 s later they separate individually and 8 min after land in an area located at 426 km of the launch pad. Each block can be equipped with parachutes and retrorockets which settle in the 2 containers parts (in top and bottom) to soften the landing and to allow their re-use. There was a project which envisaged to equip the blocks with retractable wings and automatic landers to enable them to make a self-directed descent and a landing on a runway.
The blocks of the first stage are envisaged to be re-used 10 times, the machines and systems of flights 15 times, the engines 27 times.
In the first flights the blocks were not equipped with parachutes nor of retrorocket, because the monitoring equipment was installed there.

2nd stage

The central block (second stage) separates 480 s after the launch at an altitude of 115 km, and fall to the antipodes from the starting point, in the Pacific Ocean. Such a scenario excluded the contamination of the low orbits of the ground by the remains of the launchers (which would spend several days or month before disintegrating in the dense layers of the atmosphere). The end of the orbiting phase is dealt with by the engines of Buran or the engines of the block containing the payload which have a 3 td stage function.
Blocks of the rocket "Waterspout" and "Vesuvius" ("Смерч" and the "Везувий") were supposed to be used as 3 td stage. Thus, in this configuration Energia was able to put into geostationary orbit loads going up to 18 t, for a trajectory towards the Moon 32 t, and for Mars or Venus 28 t. Other projects envisaged the use of Energia to send loads from 5 to 6 t towards the Sun or Jupiter.

Assembly

The Energia launcher is assembled horizontally to the support Я block. They will be transported and erected by the conveyor on the launching pad. This Я block ensures the mechanical, electric, pneumatic connection between Energia and the launching pad, it is by this block which all the cables and pipes go through by. After the launch of the block remained on the spot and will be re-used.

Safety

The safety and the viability of Energia are important points of the requirements, this is why a special program is in charge of the validation of the work done on the experimental and tests installations.
All the vital parts of the rocket are doubled, including the operation engines, the conduits actuators, the pumps, the power supplies and the explosives. The rocket is equipped with a diagnosis system of engines's breakdowns or separation system which makes it possible to the on-board computer of Buran "to take a decision" to minimize the loss of the payload or the crew. Thus, the driving software takes into account nearly 500 alternatives situations of accidents and their parades.

1st Flight

At the time of the first launch of Energia a great program of work and studies were completed. In total more than 200 experimental installations were created, 34 large-sized assemblies, moreover the blocks of the first stage had already accomplished 6 flights with the "Zenith".

The first launch of Energia took place on May 15, 1987 with "Polyus" ("Полюс") from the cosmodrome at Baïkonour. The rocket went slightly on the left then rectified the position, it separated normally from "Pole", but the Polyus's engines did not succeed to put it into orbit because of a failure in the autonomous management system. The second launching of Energia take place with Buran on November 15, 1988 (the attempt of October 29 failed at t -51s), it was a success.

Energia's flight path took it Siberia and the North Ocean. While the Soviets have viewed reusability as virtuous intrinsically, they clearly not wedded to the that high flight rates, and lower costs were linked inextricably. Moreover, the never operated under the that the Buran would once a week, as Americans did for our It is also worth that the Energia booster launched from a pad was also used as test stand. In comparison, rockets, including the Space Main Engines, are launched tested at totally separate Such dual functionality speaks the Soviets' emphasis on designs and adaptability. On other hand, the Soviets the Buran launch pad for that launch vehicle, of modifying an older pad.

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