Block D
Encyclopedia
Blok D is an upper stage used on Soviet
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

 and later Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

n expendable launch system
Expendable launch system
An expendable launch system is a launch system that uses an expendable launch vehicle to carry a payload into space. The vehicles used in expendable launch systems are designed to be used only once , and their components are not recovered for re-use after launch...

s, including the N1, Proton-K
Proton-K
The Proton-K, also designated Proton 8K82K after its GRAU index, 8K82K, is a Russian, previously Soviet, carrier rocket derived from the earlier Proton. It was built by Khrunichev, and is launched from sites 81 and 200 at the Baikonur Cosmodrome in Kazakhstan...

 and Zenit. There were plans to use it for some other rockets as well (project Air Launch).

The stage (and its derivatives) has been included in more than 250 launched rockets . By 2002 its modification Blok DM had a 97% success rate in 218 flights since 1974, and 43 successful missions in 1997-2002.

The stage was developed in 1960s as the fifth stage ('Д' is the fifth letter in the Cyrillic alphabet) for the Soviet Moonshot
Soviet Moonshot
The Soviet manned lunar programs were a series of programs pursued by the Soviet Union to land a man on the Moon in competition with the United States Apollo program to achieve the same goal set publicly by President John F. Kennedy on May 25, 1961...

 N1 rocket
N1 rocket
N-1 was a heavy lift rocket intended to deliver payloads beyond low Earth orbit, acting as the Soviet counterpart to the NASA Saturn V rocket. This heavy lift booster had the capability of lifting very heavy loads into orbit, designed with manned extra-orbital travel in mind...

. The stage first flew in March 1967 while testing Zond of the moonshot program system. During manned lunar flight Blok D would be used for mid-course corrections on the flight to the Moon, then to place the lunar orbiter and lander into a lunar orbit, and decelerate moon-lander
LK Lander
The LK was a Soviet lunar lander and counterpart of the American Lunar Module . The LK was to have landed up to two cosmonauts on the Moon...

 out onto its landing trajectory.

Blok D was also included as fourth stage of Proton rocket
Proton rocket
Proton is an expendable launch system used for both commercial and Russian government space launches. The first Proton rocket was launched in 1965 and the launch system is still in use as of 2011, which makes it one of the most successful heavy boosters in the history of spaceflight...

 and as such flew on unmanned Soviet missions to Moon, Mars
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...

 and Venus
Venus
Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. The planet is named after Venus, the Roman goddess of love and beauty. After the Moon, it is the brightest natural object in the night sky, reaching an apparent magnitude of −4.6, bright enough to cast shadows...

. It is still used in Proton K configuration of the rocket (the newer Proton M uses Briz-M
Briz-M
The Briz-M , is a Russian orbit insertion upper stage manufactured by Khrunichev State Research and Production Space Center and used on the Proton-M rocket.- Characteristics :...

 as fourth stage).

Blok DM also flies as the third stage for Zenit-3SL rocket, which is used by the Sea Launch
Sea Launch
Sea Launch is a spacecraft launch service that uses a mobile sea platform for equatorial launches of commercial payloads on specialized Zenit 3SL rockets...

 project to launch geostationary satellites. In 2002 the failure of a Blok DM3—used in the attempted launch of Astra 1K
Astra 1K
Astra 1K was a communications satellite manufactured by Alcatel Space for SES Astra. When it was launched on November 25, 2002 it was the largest civilian communications satellite ever launched, weighing...

 -- caused considerable concern.

The stage uses liquid oxygen
Liquid oxygen
Liquid oxygen — abbreviated LOx, LOX or Lox in the aerospace, submarine and gas industries — is one of the physical forms of elemental oxygen.-Physical properties:...

 (LOX) and kerosene
Kerosene
Kerosene, sometimes spelled kerosine in scientific and industrial usage, also known as paraffin or paraffin oil in the United Kingdom, Hong Kong, Ireland and South Africa, is a combustible hydrocarbon liquid. The name is derived from Greek keros...

 as propellants, and has one single-chamber RD-58
RD-58
The RD-58 is a rocket engine, developed in the 1960s by OKB-1, now RKK Energia. The project was managed by Mikhail Melnikov The engine was initially created to power the Block D stage of the Soviet Union's abortive N-1 rocket. Derivatives of this stage are now used as upper stages on some Proton...

 main engine. The LOX tank has a spherical shape; the kerosene tank is toroidal, inclined to 15 degrees for better fuel extraction, with the engine mounted in the center of torus. Tanks include the first pump stage for the engine; the main pump is mounted on the engine.

Blok D weighs 3.5 tons during liftoff, but some parts are jettisoned and the dry mass in space is 2.5 tons. It has 5.70 meters length and generates 83.300 kN thrust for 600 seconds burn time. Blok D was modified as Blok DM in 1974, with 11D-58S engine. The unit cost is $4 million.

Modifications

RKK Energia, the company that created Blok D, used it as a platform for many modifications over many years for different purposes; for example, the main propulsion unit on Buran started as a modification of the Blok D.
  • Blok DM (1974) - Blok D's modification for Earth-based orbits
  • Blok DM-2 (1982) - Used (as recently as 2009) with Proton M for GLONASS
    GLONASS
    GLONASS , acronym for Globalnaya navigatsionnaya sputnikovaya sistema or Global Navigation Satellite System, is a radio-based satellite navigation system operated for the Russian government by the Russian Space Forces...

     launches http://spaceflightnow.com/news/n0912/14glonass/
  • Blok DM-2M
  • Blok DM-3
  • Blok DM-5
  • Blok DM1 - commercial Blok DM-2
  • Blok DM2 - commercial Blok DM-5
  • Blok DM3, DM4 (1996) - commercial Blok DM-2M
  • Blok DM-SL (1999, derivative of DM3) - used in Sea Launch
    Sea Launch
    Sea Launch is a spacecraft launch service that uses a mobile sea platform for equatorial launches of commercial payloads on specialized Zenit 3SL rockets...

     missions as upper stage of Zenit 3SL rocket,

External links

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