Blok E (or Block E) is the propulsion unit of

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, ...

lunar module LK, developed in the 1960s by

Yuzhnoye Design Bureau Pivdenne Design Office ( uk, Державне конструкторське бюро «Південне» ім. М. К. Янгеля , lit=State design bureau "Southern", named after M. K. Yangel, translit=Derzhavne konstruktors ...

as a part of the manned lunar landing program. Blok E was designed to soft land the LK on the surface of the Moon after orbital velocity was cancelled by

Blok D Blok D (russian: Блок Д meaning Block D) is an upper stage used on Soviet and later Russian expendable launch systems, including the N1, Proton-K and Zenit. The stage (and its derivatives) has been included in more than 320 launched roc ...

. Later the same stage would fire for the second time for the liftoff and ascent from the Moon to rendezvous with the orbiting

Soyuz 7K-LOK The Soyuz 7K-LOK, or simply LOK (russian: Лунный Орбитальный Корабль, translit=Lunniy Orbitalny Korabl meaning "Lunar Orbital Craft") was a Soviet crewed spacecraft designed to launch men from Earth to orbit the Moon, devel ...

. Blok E used RD-858 (or 11D411), which has one nozzle and is deeply throttleable (from 2050 kg to 858 kg of thrust), as the primary engine. The backup engine was RD-859 (or 11D412), which has two nozzles. Together, the two engines formed the propulsion system designated 11D410. Both engines burned a mix of unsymmetrical dimethyl hydrazine and nitrogen tetroxide. The

hypergolic propellant A hypergolic propellant is a rocket propellant combination used in a rocket engine, whose components spontaneously ignite when they come into contact with each other. The two propellant components usually consist of a fuel and an oxidizer. Th ...

components guaranteed their easy storage during a lunar expedition lasting at least 11 or 12 days. The engines were equipped with clam-shell doors to prevent damaging it while staying on the surface of the Moon. There were four additional vernier engines placed between main and backup engine nozzles. Additionally to the main engine, the backup engine and the verniers, the stage was equipped with eight low-thrust reaction control thrusters feeding off a common propellant reserve. These thrusters had been provided by OKB-300, the Stepanov Aviation Bureau.

References

Notes

:a.Blok E was part of the N1-L3 lunar expeditionary complex, which was supposed to be launched on the rocket with the same name. As the N1 did not finish development, only dummy stages were launched on the third and fourth launch ( serial 6L and 7L). {{N1-L3 Soviet inventions Rocket stages

See also

References

Notes