Block E

Block E was designed as a part of the N1-L3 (11A52) space launch system to ensure landing of the Lunar Vehicle (LK) with a cosmonaut on the Moon, and subsequent liftoff from the Moon, injecting the Lunar Vehicle into lunar orbit for docking with the manned lunar orbiter. The launch system comprised a three-stage launch vehicle, N-1 (11А52), and a four-stage upper module, L3, that served for delivery of two cosmonauts from Earth orbit to lunar orbit, LK landing on the Moon and return to the orbit, and for the crew return to Earth.

NPO Energia from Korolev, Russia, was assigned head designer of the N1-L3 (11A52) system and the Lunar Vehicle. Yuzhnoye SDO designed Block E, which was the propulsion system for the Lunar Vehicle LK. Besides Block E, the LK consisted of the cosmonaut cabin and the lunar landing unit (LLU). The cosmonaut cabin contained control system equipment, crew life support systems, attitude control engines, and the cosmonaut compartment. The LLU cushioned the impact at landing on the Moon, provided LK’s stable position on the surface, and served as a launch pad for LK’s lifting off from the Moon.

To increase the reliability, Block E included two similar engines, main 11D411 and backup 11D412. The main engine provided a dual-burn capability (the first burn would take place during landing on the Moon, the second burn at liftoff). The backup engine would ignite either in the landing phase, if the main engine failed, to ensure the LK’s return to the lunar orbit, or at liftoff from the Moon, together with the main engine, backing it up and enhancing reliability of the liftoff from the LLU.

Block E and all other Lunar Vehicle modules successfully passed all ground tests. The time had come to test in flight. The N1 launch vehicle was not ready, so it was decided to use the Soyuz rocket (11A551) for the test flights. The first launch was performed on November 24, 1970; the second, on February 26, 1971, the third, on August 12, 1971. All tests were successful.

Performance of Block E was successfully demonstrated, and underlying engineering solutions were verified. Unfortunately, the N1 launch vehicle never got off the ground, and the N1-L3 program was closed in 1974.

Basic Specifications