N1 version
N1 N1-L3 (11A52)
The only N1 configuration that ever flew: five stages, 105.3 m tall, 2,750 tonnes at lift-off and 95,000 kg to low Earth orbit. Four launches between 1969 and 1972, four failures.
- February 21, 1969
- First launch
- 95,000 kg
- LEO capacity
- No
- Reusable
History
The flight configuration
The N1-L3 stacked five stages: the first three (the N1 proper) to reach a low parking orbit and two more (the L3 assembly) for trans-lunar injection and lunar orbit insertion. It stood 105 m with its L3 payload and 17 m wide at the base, weighing 2,750 tonnes fully fuelled. The three lower stages formed a single frustum while the L3 section was mostly cylindrical.
Block A
Its first stage, Block A, was for over fifty years the most powerful rocket stage ever flown: 45,400 kN of thrust, far above the Saturn V's 33,700 kN, a record that fell only to SpaceX's Super Heavy. It got there with 30 NK-15 engines in two rings, 24 around the outer edge and 6 in the core. Managing them fell to KORD, a control system that shut engines down on anomaly and turned out to be one of the rocket's weak points: it had serious design flaws, poorly programmed logic, and an operating frequency of 1000 Hz that coincided with vehicle vibrations.
The four flights
Vehicle 3L, launched on 21 February 1969, suffered an engine fire and exploded at 12 km. 5L, the first night launch, failed and demolished pad 110 East. 6L, from pad 110 West, had deficient roll control and was destroyed at 51 seconds. 7L, the last, lost its engines at 40 km and propellant-line hammering ruptured the fuel system. Vehicle 4L never flew: cracks appeared in its Block A liquid oxygen tank and the airframe was eventually scrapped.