Blok D (russian: Блок Д meaning Block D) is an

upper stage A multistage rocket or step rocket is a launch vehicle that uses two or more rocket ''stages'', each of which contains its own engines and propellant. A ''tandem'' or ''serial'' stage is mounted on top of another stage; a ''parallel'' stage is ...

used on

Soviet The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...

and later

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-ei ...

expendable launch system An expendable launch system (or expendable launch vehicle/ELV) is a launch vehicle that can be launched only once, after which its components are either destroyed during reentry or discarded in space. ELVs typically consist of several multistage ...

s, including the N1, Proton-K and Zenit. The stage (and its derivatives) has been included in more than 320 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 N1 rocket. 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 out onto its landing trajectory. Blok D was also included as fourth stage of Proton-K and as such flew on unmanned Soviet missions to Moon,

Mars Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin at ...

( Mars 3) and

Venus Venus is the second planet from the Sun. It is sometimes called Earth's "sister" or "twin" planet as it is almost as large and has a similar composition. As an interior planet to Earth, Venus (like Mercury) appears in Earth's sky never f ...

. It was used in the Proton-K configuration of the rocket and is still in use in the newer

Proton-M The Proton-M, (Протон-М) GRAU index 8K82M or , is an expendable Russian heavy-lift launch vehicle derived from the Soviet-developed Proton. It is built by Khrunichev, and launched from sites 81 and 200 at the Baikonur Cosmodrome in Ka ...

variant (along with the Briz-M). Blok DM also flies as the third stage for the Zenit-3SL rocket, which is used by the Sea Launch project to launch geostationary satellites. In 2002 a Blok DM3 failed in the attempted launch of Astra 1K. The stage uses

liquid oxygen Liquid oxygen—abbreviated LOx, LOX or Lox in the aerospace, submarine and gas industries—is the liquid form of molecular oxygen. It was used as the oxidizer in the first liquid-fueled rocket invented in 1926 by Robert H. Goddard, an app ...

(LOX) and

kerosene Kerosene, paraffin, or lamp oil is a combustible hydrocarbon liquid which is derived from petroleum. It is widely used as a fuel in aviation as well as households. Its name derives from el, κηρός (''keros'') meaning " wax", and was re ...

as propellants, and has one single-chamber RD-58 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. Since 1990, all variations of this stage have been built in the Krasnoyarsk Machine-Building Plant.

Modifications

RKK Energia PAO S. P. Korolev Rocket and Space Corporation Energia (russian: Ракетно-космическая корпорация «Энергия» им. С. П. Королёва, Raketno-kosmicheskaya korporatsiya "Energiya" im. S. P. Korolyov ...

, 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.

Variants

References

External links

Russian Space Web
* https://web.archive.org/web/20120716190506/http://www.friends-partners.org/oldfriends/jgreen/blockd.html

{{N1-L3 Soviet inventions Rocket stages Rocket engines using kerosene propellant

Modifications

Variants

See also

References

External links