Nositel (N) -1

The originally N-1 was intended to launch heavy satellites into Earth orbit. In consisted of three stage all using liquid oxygen and kerosene propellants. The N-1 heavy-lift contained six spherical tanks (two on each of the first three cone-shaped stages), the fuel tank being above the oxidiser tank. These tanks were produced from magnesium-nickel alloy AGM6, and the N-1 external construction was duralumin D16.

The first stage , Block A, had 30 engines, arranged in circles of 24 and 6. The engines NK-15 were developed by the Kuznetsov Design Bureau. The engines could not be gimballed to steer the vehicle. Instead, the motors were selectively throttled to achieve the correct trajectory. The 30 main engines (+4 drive engines) have a thrust of 154 tons each and burning 150 seconds. The first stage had  a 12.9 m diameter LOX tank and a 10 m diameter fuel tank. On the  lower part of this stage were installed 4 grating-type stabilizers.
The second stage, Block B, featured 8  Kuznetsov engines NK-15V. The engines differed slightly from those on the first stage in that they had longer nozzles for better performance at higher altitudes. Again , guidance was achieved through selective throttling. The 8  engines have a thrust of 179 tons each. The second stage had a 8 m diameter LOX-tank and a 7 m diameter fuel tank.
The third stage, Block V, employed four engines NK-21 of different design. The third stage engines could be gimballed and have a thrust of 41 tons each. The stage had  a 5.8 m diameter LOX tank and a 4.7 m diameter fuel tank.
This was the basic N-1 vehicle. The lunar program required the addition of two more rocket stages, a lunar lander and a spacecraft for the return to Earth. These components came under the name L-3. The program as a whole was known as N-1/L-3.
The next stage (Block G) concerned the lunar spacecraft and had a total mass to 98 tons. Each block had only one engine NK-19, a toroidal fuel tank and a cylindrical oxidiser tank. This block is for acceleration and next Block D (engine RD-58) for deceleration near the moon. The last  was connected with Lunar Orbital Cabin (LOK) and Lunar Cabin (LK). On the top of the N-1 booster was installed a 10 m long solid rocket launch escape system with a mass of 7 tons. The L-3 composition is 43.7 m long, the total booster mass is 2.788 tons.
The N-1 booster had a built-in safety failure system (KORD) which controlled each engine in each stage. If 4 engines in the first stage  failed the rocket would still work, likewise, if a pair of engines in the second stage or one engine in the third stage failed, the N-1 was still capable of reaching low Earth orbit.
The N-1/L-3 was finally ready for its first test flight in 1969. The booster was to carry a Soyuz-LOK and a mock-up of the Lunar Cabin, but 70 seconds after lift-off on February 21 the rocket failed:

• The first  N-1 booster lifted off on 21.02.1969. First stage ignition occurred at T-4 seconds. Engine no.12 and 24 shutdown after 3-7 seconds because of on error in the KORD control system. The flight was able to continue because the remaining engines compensated for the failure. At  T+25 seconds the engines were throttled down until the vehicle safely passed through the period of maximum dynamic pressure. At T+65-66 seconds the engines throttled back to full power but the much faster than had been expected causing strong vibration. The oxidiser pipeline of one engine broke spilling liquid oxygen and a fire broke out. All first stage engines were apparently shut down at T+70.

• A second  launch attempt was made on 03.07.1969. Soon  after ignition (6-9 seconds) one of the oxidiser pumps failed, causing the engines to shut down. The rocket fell back towards the launch pad. The launch escape system worked well and the payload was delivered.

• The third launch took place on 27.06.1971. Soon  after lift-off at a altitude of about 250 m and 8-10 seconds after ignition the booster guidance system  failed and an unplanned rotation about the vertical axis began, causing breakup of the support structure between the second-third stages.

• The last launch attempt took place on 23.11.1972. The  N-1 first stage engines worked well to 107 seconds, but then an unexpected vibration began in the first-second stages causing flight  termination about 40 seconds before first stage engines normally shut down. The booster exploded.

Two more rockets had been fully assembled and readied for flight but in 1974 the program was cancelled.

Five improved NK-engines was developed by Kuznetsov as part of an another variant N-1:
    The NK-33 and NK-43 engines are upgraded versions of the NK-15 and NK-15V engines.
    The NK-31 and NK-39 engines are upgraded versions of the NK-19 and NK-21 engines.

    The RD-57 (11D57) LH2/LOX engine was developed as a replacement for the NK-31 and NK-39
    Kerosene/LOX engines for a upgraded variant N-1M.