Rocket "Rokot" - Russian booster rocket,which is capable of delivering light and medium payloads to orbit. With the Briz-KM upper stage it takes up to 2150 kg of payload to an altitude of 200 km.
History of creation
What is the Rokot launch vehicle?It is based on the UR-100N intercontinental ballistic missile, also known as the SS-19 Stiletto. The development of the UR-100N began in 1970 with the aim of improving the ICBM UR-100 and creating a large aircraft capable of lifting heavier loads.
Flight tests were conducted from 1973 to1975, and the system began to function in 1974. By 1978, the total stock of 190 missiles was reached. An improved version, called the UR-100UTTH, was commissioned in 1979 and replaced the old models, reaching a maximum margin of 360 units.
Nuclear shield
Ракеты УР-100 могут нести до шести независимых individual-guided warheads with a range of 10,000 km. They can be prepared for launch within 25 minutes at any time in a 22-year shelf life. Intercontinental ballistic missiles UR-100 are still in service.
После окончания холодной войны в ГКНПЦ имени Khrunichev’s weapons were redeveloped and equipped with modern avionics and the Briz-KM upper stage, which allowed it to be used as space launch vehicles. NPO Mashinostroenie also reconstructed the UR-100 into a launch vehicle, but without significant modifications, creating a less flexible but cheaper apparatus for launching small payloads into low near-earth orbit. In this configuration, it is known as the Arrow.
From Baikonur to Plesetsk
The first launch of the Rokot rocket was held on November 201990 from the Baikonur Cosmodrome, Kazakhstan. The first orbital flight took place on December 26, 1994. And in 1995, Eurockot was formed, with the help of which the Russian launch vehicle Rokot was launched into the market of commercial launches.
The company has acquired 45 spacecraft.In 2000, Astrium bought a 51% stake in Eurockot. The remaining 49% are owned by the Khrunichev State Research and Production Space Center. In May 2000, from the Plesetsk cosmodrome, the Rokot was launched not from a mine, as it did at Baikonur, but from a land transport container.
Rocket "Roar": characteristics
Spacecraft is aa two-stage liquid fuel booster, usually equipped with the last stage "Breeze-KM", which is capable of delivering a payload weighing up to 2140 kg to a low near-earth orbit and 1200 kg to a sun-synchronous one.
The characteristics of the Rokot carrier rocket are as follows:
- height is 29,15 m,
- main diameter 2.5 m,
- starting weight 107 000 kg,
- fuel - asymmetric dimethyl hydrazine (heptyl) and nitrogen tetroxide.
First stage
First stage lightweight boosterThe Rokot is 17.2 m long and 2.5 m in diameter. The nitrogen tetroxide tank is located above the tank with asymmetric dimethyl hydrazine. Two tanks are separated by a common partition. Lifting weight - 77 200 kg, inert - 5700 kg.
В первой ступени используются три двигателя RD-0233 and one RD-0234. Their designs are similar, but RD-0234 has a heat exchanger that supplies compressed gas to the fuel tanks in order to maintain the necessary pressure in them throughout the first phase of the flight.
All engines - with closed-loop turbopumps.Each provides 470 kilonewton thrust, for a total of 1,870 kN or 190,700 kg. Vacuum thrust first stage - 2070 kN (211.100 kg), 520 kN per engine.
Management is provided by individual gimbal suspension of each of the four engines. Opening hours - 121 s.
The separation is carried out in hot mode.The second-stage vernier motor ignites before the separation stage. Special hatches direct the jet of four nozzles out. After starting the pyrotechnic mechanism, the vernier exhaust pushes away the spent first stage. In addition, it is equipped with four solid propellant rocket engines that, after separation, are ignited to remove it to a safe distance.
Second stage
The second stage is 3.9 m long and 2.5 m in diameter. Its mass is 1,500 kg plus 10,700 kg of fuel. The oxidizer tank is also located above the fuel tank and is separated from it by a common partition.
The stage is equipped with engines with a closed cycle turbopump: the main RD-0235 and the four-chamber vernier RD-0236 to control the direction of flight.
RD-0235 has a rated vacuum of 240 kN (24,470 kg), providing a pulse for 320 s.
RD-0236 provides traction 15.76 kN (1 607 kg) and293 s work Each of the four nozzles of the engine through gimbal suspension can move along one axis, providing control of the orientation of the rocket in the second phase of flight. It also uses a hot gas supply system to create the necessary pressure in the tanks.
Upper stage
Rocket "Rokot" is equipped with an upper stage, which consists of three main compartments - the motor, sealed cargo compartment and the intermediate compartment, which is connected to the second stage.
"Breeze-KM" has 2.6 m in length, 2.5 m in diameter andweight 1320 kg The heptyl tank is located above the oxidizer tank. The latter has a conical shape and a recess to accommodate the main engine. "Breeze-KM" is able to accommodate 1 665 kg of UDMH and 3310 kg of oxidizer. To maintain the required pressure in the tanks and to control the pneumatics, high-pressure helium is used.
The central part of the unit consists of a tank withoxidant located above the fuel tank. Both tanks are equipped with hydraulic and pneumatic systems, as well as internal partitions to prevent liquid from hitting the walls of the structure. They have a toroidal shape with a notch in the lower part for the main propulsion system, which made it possible to minimize the length of the step. Below is the compartment with the main power plant and engines stabilization and orientation, and spherical tanks with helium and fuel for them. The equipment is covered with thermal insulation to prevent excessive cooling of the fuel, which affects its viscosity and can lead to freezing of pipelines and tanks.
Instrument bay
В верхней части блока в перевернутом усеченном the cone is a compartment for equipment, consisting of frames, providing the installation of various controllers, telemetry modules, batteries and communication systems. Adapters up to 2.49 m in diameter are supported.
In the lower part there is a 60 cm adapter connecting the Breeze-KM to the second stage, as well as providing fastening of fairings.
In the upper stage, two fuelSystems: low pressure for main engines and high pressure engines for stabilization and orientation. Both use asymmetric dimethyl hydrazine and nitrous oxide, which ignite immediately after they come in contact with each other.
Booster motors
Двигатели управления ориентацией, используемые на "Breeze-KM" are called 17D58E and provide a nominal thrust of 13.3 N. Each block is 14 cm long and weighs 550 g. The jet micromotor operates at a mixing ratio of 1: 1.85 and a nominal input pressure of 14.7 bar but it is able to withstand a large pressure range from 7.8 to 34.3 bar. To control the orientation of the power plants are used in a pulsed mode with a minimum operating time of 0.03 s, but the 17D58E is also certified to operate in continuous mode for up to 10,000 seconds. The engine maintains 450,000 duty cycles.
Overclocking power supply system
"Breeze-KM" is equipped with its own power system,consisting of batteries and power distribution systems that provide up to 7 hours of operation in orbit. The instrument compartment includes telemetry devices with transmitters and antennas, as well as tape recorders for storing and transmitting data. The guidance, navigation and control system is responsible for the flight at all stages. It consists of a platform with inertial guidance, including a 3-axis gyroscope with on-board computers. The system has triple redundancy with majority decision making. It is completely autonomous and cannot be controlled from the outside.
Cowl
Ракета «Рокот» оснащена обтекателем, который был specially designed for the commercial version of the spacecraft. It is installed on the instrument compartment of the upper stage. It consists of two parts of 7.8 m in length, which together have an elliptical shape of 2.5 to 2.62 m in diameter. Space for payload is 5.9 m in height.
The fairing protects the spacecraft fromaerodynamic, thermal and acoustic effects exerted on him during the flight in the atmosphere. When the rocket leaves it, the fairing is reset by opening mechanical locks holding the two semi-shells along the vertical line of separation using a pyrotechnic device located in the nose of the fairing. Then, on the horizontal separation line, several pyrobolts are shot, which allows the fairing to disperse due to spring pushers. The hinges at the base provide rotation away from the rocket and clear separation.
System Storage and Startup
Unlike the SS-19, which start from the mines,the launch of the Rokot carrier rocket is made from the transport and launch container at the Plesetsk cosmodrome, Russia. Rockets are stored for a long time, which requires monitoring of climatic conditions and maintaining a nitrogen atmosphere. Transportation and installation on the launch pad are also made in a container. In addition, the container contains equipment for pre-launch preparation and environmental protection.
He is moving apart before the launch and on the launch vehicleset payload, upper stage and fairing. Interfaces for refueling, as well as power and data cables are connected to the container. In the vertical position, the Rokot rocket rests on the ring at the bottom of the container. During takeoff, discontinuous cables are disconnected by mechanical systems. During the start, the device is guided by two rails. The container protects the launch pad from engine emissions and is used once.
Interesting Facts
The launch of the Rokot missiles will be terminated in 2017 after the completion of the planned federal and commercial launches.
The name SS-19 Stiletto is the name of NATO forThis type of ICBM. SS stands for land-to-earth system, and the number 19 and the name Stiletto are assigned to this type of intercontinental ballistic missiles. In Russia, the official name of SS-19 is RS-18 and UR-100N.
The best thing about the space rocket "Rokot" saysits reliability, which was confirmed by 27 successful launches of 29. And out of 150 launches of the SS-19, only 3 failed at the very beginning of their operation in the 1970s. Test launches of the SS-19 and Rokot are held annually as part of testing the reliability of the spacecraft and exercises of the space forces.
