N1 (rocket)

This article is about the Soviet rocket. For the Japanese rocket, see N-I (rocket).

N1

Mockup at the Baikonur Cosmodrome in late 1967
Function	Super heavy-lift launch vehicle for crewed lunar mission
Manufacturer	OKB-1
Country of origin	USSR
Cost per launch	US$604 million in 1985 dollars ($1.81 billion in 2025)
Size
Height	105.3 m (345 ft)
Diameter	17 m (56 ft)
Mass	2,750,000 kg (6,060,000 lb)
Stages	5
Capacity
Payload to LEO
Mass	95,000 kg (209,000 lb)
Payload to TLI
Mass	cca 33,000 kg (73,000 lb)
Associated rockets
Comparable	Saturn V
Launch history
Status	Cancelled during development
Launch sites	Baikonur, Site 110
Total launches	4
Success(es)	0
Failure	4
First flight	21 February 1969
Last flight	23 November 1972
First stage – Block A
Diameter	17 m (56 ft)
Powered by	30 × NK-15
Maximum thrust	SL: 45,780 kN (10,290,000 lbf) vac: 46,320 kN (10,410,000 lbf)
Specific impulse	SL: 297 s (2.91 km/s) vac: 318 s (3.12 km/s)
Burn time	125 seconds
Propellant	LOX / RG-1
Second stage – Block B
Powered by	8 × NK-15V
Maximum thrust	14,064 kN (3,162,000 lbf)
Specific impulse	325 s (3.19 km/s)
Burn time	120 seconds
Propellant	LOX / RG-1
Third stage – Block V
Powered by	4 × NK-19
Maximum thrust	1,800 kN (400,000 lbf)
Specific impulse	346 s (3.39 km/s)
Burn time	370 seconds
Propellant	LOX / RG-1
Fourth stage – Block G
Powered by	1 × NK-21
Maximum thrust	329 kN (74,000 lbf)
Specific impulse	346 s (3.39 km/s)
Burn time	443 seconds
Propellant	LOX / RG-1
Fifth stage – Block D
Powered by	1 × RD-58
Maximum thrust	83.36 kN (18,740 lbf)
Specific impulse	349 s (3.42 km/s)
Burn time	600 seconds
Propellant	LOX / RG-1

The N1 (from Ракета-носитель Raketa-nositel', "Carrier Rocket"; Cyrillic: Н1, GRAU index: 11A52, Sheldon: G-1-e, DoD: SL-15) was a super heavy-lift launch vehicle of the Soviet space program intended for crewed travel to the Moon and beyond. All four launch attempts between 1969 and 1972 failed. Studied and designed by OKB-1 since 1959, it was the counterpart to the US Saturn V.

A five-stage kerolox-fuelled rocket, its Block A was the most powerful rocket stage flown for over 50 years, at 45 meganewtons of thrust, until the SpaceX Super Heavy. Block A's large cluster of thirty NK-15 engines, prone to individual failures, was managed by KORD, an analog computer which shut down engines opposite the failure, to maintain attitude control. Block B and V used eight and four hot staged engines respectively, planned to bring the rocket to low Earth orbit. Dangers of the complex engine cluster and fuel feeder systems were not discovered earlier as static fires were not conducted on the Block A. Its second test flight resulted in one of the largest conventional explosions ever, that disabled its Site 110 launch pad at Baikonur Cosmodrome for 18 months.

The N1-L3 aimed to compete with the US Apollo program for a crewed Moon landing, using a similar lunar orbit rendezvous method. The rocket had three stages, carrying the L3 lunar payload into low Earth orbit with two cosmonauts. The L3 contained the Block G trans-lunar injection stage; Block D for mid-course corrections, lunar orbit insertion, and initial surface descent; single-pilot LK lander; and two-pilot Soyuz 7K-LOK orbital spacecraft for return to Earth.

The N1 started development in October 1965, almost four years after the Saturn V. The project was derailed by the death of its chief designer Sergei Korolev in 1966; the program was suspended in 1974 and canceled in 1976. The TMK project of crewed Mars and Venus flybys also relied on the N1. OKB-1 later developed Energia, the only Soviet super-heavy lift rocket to reach orbit, flying in 1987 and 1988. Details of the Soviet crewed lunar programs were kept secret until the USSR was nearing collapse in 1989. From 2013, the NK-33 engines, built for the N1F improvement cancelled in 1974, were adapted to the smaller US Orbital Sciences Antares 100 rockets and Russian Soyuz 2.1v rockets.