N1 (rocket)

The N1, also designated N1-L3, was a Soviet super heavy‑lift launch vehicle developed between 1965 and 1976 for the purpose of sending cosmonauts to the Moon. It was the Soviet Union’s counterpart to the United States’ Saturn V. The vehicle was designed under the leadership of chief designer Sergei Korolev and later led by Vasily Mishin after Korolev’s death in 1966. The N1 program was managed by OKB 1 (later the Moscow Machine-Building Plant named after N. P. Korolev).

Design and Configuration

• Stages: The original N1 was a three‑stage rocket, later variants included a fourth stage for trans‑lunar injection.
• First Stage (Block A): Powered by 30 NK‑15 (later NK‑33) liquid oxygen/kerosene engines arranged in a circular “octagonal” pattern. Each engine produced approximately 1.5 MN thrust, giving the stage a total thrust of about 45 MN at sea level.
• Second Stage (Block B): Utilised four NK‑15V engines, providing roughly 6 MN thrust.
• Third Stage (Block V): Employed a single NK‑21 engine.
• Fourth Stage (Block L): For lunar missions, the Block L stage used a single NK‑33 engine to perform trans‑lunar injection.
• Payload Capacity: Approximately 95 t to low‑Earth orbit (LEO) and 23 t to a translunar injection (TLI) trajectory.
• Height: Approximately 105 m (344 ft).
• Mass: Fully fueled mass around 2,735 t.

Development History

The N1 was conceived as part of the Soviet lunar program, which aimed to land a cosmonaut on the Moon before the United States. After the cancellation of earlier lunar mission proposals (such as the L1 and L3 projects), the N1 became the centerpiece of the Soviet lunar effort. The rocket was intended to launch the L3 lunar expedition complex, comprising the LK‑1 lunar lander, the LK‑1 crew module, and associated support hardware.

Test Flights

Four uncrewed launch attempts were made between 1969 and 1972:

1. N1‑3L (21 February 1969): Failed seconds after liftoff due to engine shutdowns and loss of control of the first stage.
2. N1‑5L (3 July 1969): Exploded on the launch pad shortly after ignition, causing extensive damage to the launch complex at Baikonur Cosmodrome.
3. N1‑6L (27 November 1971): Experienced a catastrophic failure of the first‑stage engines, leading to an abort at approximately 70 seconds after liftoff.
4. N1‑7L (23 June 1972): The final launch, which also ended in failure after about 107 seconds when the vehicle lost thrust and collapsed.

All four missions failed to achieve orbit, and each resulted in the loss of the vehicle and the launch complex infrastructure.

Program Termination

Following the repeated failures and the successful Apollo lunar landings by the United States, Soviet leadership decided to discontinue the N1 program in 1974. Funding was withdrawn, and the remaining hardware was either scrapped or repurposed. The cancellation marked the end of the Soviet crewed lunar ambitions.

Legacy

Although the N1 never successfully flew, its development contributed to advances in several areas:

• Engine Technology: The NK‑33 and NK‑15 engines were later refurbished and marketed by Aerojet (as the AJ‑26) for use on the United Launch Alliance’s Antares rocket, and by other commercial entities for small launch vehicles.
• Heavy‑Lift Concepts: Lessons learned from the N1’s massive engine cluster informed later Russian heavy‑lift designs, such as the Energia and the modern Angara family.
• Historical Significance: The N1 remains a prominent example of Cold‑War era space competition and the technical challenges associated with a megaton‑class launch vehicle.

Specifications (N1‑L3 Configuration)

References

• Khrunov, V. M. Soviet Moon Program: The N1 Rocket. Moscow: Energia Press, 1998.
• Siddiqi, Asif A. Challenge to Apollo: The Soviet Union and the Space Race, 1945–1974. NASA History Series, 2000.
• “N1 (rocket).” Encyclopedia Astronautica, archived at https://www.astronautix.com/n/n1.html (accessed 2026).

The above information reflects the consensus of publicly available historical and technical sources.