|This article needs additional citations for verification. (June 2009)|
|Function||Manned lunar carrier rocket|
|Country of origin||USSR|
|Height||105 metres (344 ft)|
|Diameter||17.0 metres (55.8 ft)|
|Mass||2,735,000 kilograms (6,030,000 lb)|
|95,000 kg (209,000 lb)|
|23,500 kg (51,800 lb)|
|Launch sites||LC-110, Baikonur|
|First flight||21 February 1969|
|Last flight||23 November 1972|
|First Stage - Block A|
|Diameter||17.0 m (55.8 ft)|
|Thrust||50,300 kN (11,300,000 lbf)|
|Specific impulse||3.24 kN·s/kg (330 s)|
|Burn time||125 s|
|Second Stage - Block B|
|Thrust||14,040 kN (3,160,000 lbf)|
|Specific impulse||3.39 kN·s/kg (346 s)|
|Burn time||120 s|
|Third Stage - Block V|
|Thrust||1,610 kilonewtons (360,000 lbf)|
|Specific impulse||3.46 kN·s/kg (353 s)|
|Burn time||370 seconds|
|Fourth Stage (N1/L3) - Block G (Earth departure)|
|Thrust||446.00 kN (100,260 lbf)|
|Specific impulse||3.46 kN·s/kg (353 s)|
|Burn time||443 s|
The N1 was a heavy-lift rocket intended to deliver payloads beyond low Earth orbit, acting as the Soviet counterpart to the NASA Saturn V rocket. This heavy lift booster had the capability of boosting very heavy loads into orbit, designed with manned extra-orbital travel in mind. The original 24 engine design could put 75 tonnes into LEO and the redesigned 30 engine version could put 95 tonnes into LEO. (See 1.3 Space Race for more details). Development work started on the N1 in 1959. Its first stage, called Block A in Soviet nomenclature, is the most powerful rocket stage ever built and the N1 was also the first rocket to have a fully digital computer control system, far ahead of its time. The engine developed for the N1, the NK-33 was the first closed cycle engine and in the 1990s was shown to be one of the best in the world, even to the present day.
The N1-L3 version was developed to compete with the United States Apollo Saturn V to land a man on the Moon. The basic N1 launch vehicle had three stages, Blocks A, B and V, which was to carry the L3 lunar payload into low Earth orbit. The L3 contained an Earth departure stage, Block G and a mid-course correction and lunar landing assist stage, Block D, in addition to the single-cosmonaut Block Ye LK Lander spacecraft, and a two-cosmonaut Soyuz 7K-LOK lunar orbital spacecraft. The final powered descent to the lunar surface was to be carried out by the Block Ye LK Lunar Module after separation from Block D between 2,000 metres (6,600 ft) and 500 metres (1,600 ft) altitude above the lunar surface.
N1-L3 was underfunded and undertested, and started development in October 1965, almost four years after the Saturn V. The project was badly derailed by the death of its chief designer Sergei Korolev in 1966. Each of the four attempts to launch an N1 failed and the N1 program was suspended in May 1974, subsequently in 1976 the N1 program was officially canceled. Along with the rest of the Soviet manned Moon programs, the N1 was kept secret almost until the collapse of the Soviet Union in December 1991. Information about the N1 was first published in 1989 during glasnost.
Development began under the direction of Sergei Korolev at his OKB-1 Design Bureau. The original design proposed a 50-metric-ton (110,000 lb) payload intended as a launcher for military space stations and a manned Mars flyby using a nuclear engine upper stage. The N1 was the largest of three proposed designs; the N2 was somewhat smaller and intended to compete with Vladimir Chelomei's proposed UR-200, and the much smaller N3, which would replace Korolev's "workhorse" R-7 rocket. At this point the N-series was strictly a "paper project".
In March 1961, during a meeting at Baikonur, designers discussed the N1 design, along with a competing Glushko design, the R-20. In June, Korolev was given a small amount of funding for N1 development between 1961 and 1963. In May 1961 a government report, On Reconsideration of the Plans for Space Vehicles in the Direction of Defense Purposes, set the first test launch of the N1 rocket for 1965.
When the US announced in May 1961 the goal of landing a man on the Moon, Korolev proposed a lunar mission based on a new spacecraft, eventually known as Soyuz, that was designed for Earth orbit rendezvous. Several launches would be used to build up a complete moon package, one for the Soyuz, another for the lunar lander, and additional launches with cislunar engines and fuel. This approach makes the least demands on the launch vehicle, as the payload mass is reduced for any one launch. This is at the expense of requiring a rapid launch rate to ensure that the modules are built up before running out of consumables while waiting on-orbit. Even using this profile the lunar boosters and fuel were too large for any existing Soviet launcher. Korolev thus proposed development of the N1 with a 50 t (110,000 lb) payload – much smaller than the N1 design that would eventually be delivered.
To power the new design, Valentin Glushko, who then held a near-monopoly on rocket engine design in the Soviet Union, proposed a new engine, the RD-270, running on unsymmetrical dimethylhydrazine (UDMH) and nitrogen tetroxide (N2O4). This formula is hypergolic (i.e., its components ignite on contact, reducing the complexity of the combustion system), and was widely used in Glushko's existing engine designs used on various ICBMs. The propellant pair UDMH/N2O4 has a lower specific impulse than kerosene/liquid oxygen, but because the RD-270 used the much more efficient full flow staged combustion cycle, as opposed to the simple gas-generator cycle used on the American F-1 rocket engine, the specific impulse of the RD-270 was higher than the F-1.
Korolev also felt that the toxic nature of the fuels and their exhaust presented a safety risk for manned space flight. Glushko pointed out that the US Titan II rockets used to launch Gemini spacecraft burned identical propellants. The Americans also had a 5-year head start with F-1 engine development, and were still facing combustion stability problems; Glushko held it was unrealistic and unfair to expect him to stake his reputation on miraculously delivering a similar engine virtually overnight with practically no money, primitive computer technology and an inferior kerosene fuel prone to coking (leaving contaminating deposits of unburned carbon) at high temperatures, as opposed to the rocket-grade kerosene used in the Saturn V. The difference of opinions led to a falling out between Korolev and Glushko. Since Glushko refused to work on such a design, Korolev eventually gave up and decided to enlist the help of Nikolai Kuznetsov, the OKB-276 jet engine designer.
Kuznetsov, who had limited experience in rocket design, responded with a fairly small engine known as the NK-15, which would be delivered in several versions tuned to different altitudes. To achieve the required amount of thrust, it was proposed that a large number of NK-15s would be used in a clustered configuration around the outer rim of the lower-stage booster. The "inside" of the ring of engines would be open, with air piped into the hole via inlets near the top of the booster stage. The air would be mixed with the exhaust in order to provide thrust augmentation, as well as additional combustion with the deliberately fuel-rich exhaust. The ring-like arrangement of so many rocket engine nozzles on the N1's first stage could have been an attempt at creating a crude version of a toroidal aerospike engine system; more conventional aerospike engines were also studied.
Since the US Project Gemini reversed the Soviet lead in human space exploration by 1966, Korolev was able to persuade the council of chief designers to let him pursue his plans to make a lunar landing before the US. This required much larger boosters. The Central Committee of the Communist Party and Council of Soviet Ministers issued a Decree On Work on the Exploration of the Moon and Mastery of Space, piloted LK-1 circumlunar and L3 lunar landing projects and the Ye-6M lunar lander. Korolev felt that if he had the full support of the Communist Party, the military, and industry he could achieve this goal. Korolev and subsequently, V.P. Mishin after Korolev's death in January 1966, was ordered to fly the N1/L3 manned after it had flown successfully unmanned by first secretary Leonid Brezhnev.
Korolev proposed a larger N1, combined with a new lunar package known as the L3. This uprated and redesigned N1 could boost 95 metric tonnes to LEO, rather than the original N1 75 tonne to LEO capacity. This was achieved by reducing the initial LEO inclination from 65 to 52 degrees, reducing the lunar orbit from 300 km to 220 km and increasing the propellant mass by super-cooling the propellants prior to loading and adding 6 center engines to Block A (first stage in Soviet nomenclature), for a total of 30 engines, as well as marginally increasing the thrust on Block B and Block V (the second and third stages respectively). The L3 combined the lunar engines, an adapted Soyuz spacecraft (the LOK) and the new LK lunar lander in a single package.
Korolev died in 1966 due to complications after minor surgery, and the work was taken over by his deputy, Vasily Mishin. Mishin did not have Korolev's political astuteness or power, a problem that led to the eventual downfall of the N1, and of the lunar mission as a whole. Eventually in 1974 Mishin lost the support of the Central Committee Secretary Dmitriy Ustinov, a long time supporter of Korolev, who then obtained approval from Leonid Brezhnev to have Mishin replaced by rival, Valentin Glushko.
The N1 was a very large rocket, standing 105 metres (344 ft) tall. It was among the world's largest launch vehicles: smaller than the Saturn V in height, mass, and payload capability, but with a larger lift-off thrust. The N1-L3 consisted of five stages in total, three for immediate boost into orbit (the N1), and another two for the lunar portion (the L3). Fully loaded and fueled, the N1-L3 weighed 2,788 tonnes (6,146,000 lb). The lower three stages were shaped to produce a single frustum just under 17 metres (56 ft) wide at the base, while the L3 section was cylindrical and had a core diameter of 4.4 metres (14 ft). The payload shroud that protected the L3 complex consisted of a cylindrical section 6 metres (20 ft) wide that covered Blocks G and D, before tapering off to smaller diameters at the top of the stack. The conical shaping of the lower stages was due to the arrangement of the tanks within, a smaller spherical kerosene tank on top of the larger liquid oxygen tank below.
The first stage, Block A, was powered by 30 NK-15 engines arranged in two rings, the main ring of 24 at the outer edge of the booster, the inner of 6 at about half diameter. The engines were the first ever staged combustion cycle engines. The control system was primarily based on differential throttling of the engines in the outer ring for pitch and yaw. Roll control was maintained by routing engine turbine exhaust through six canted nozzles. After the 6L launch, which lost roll control, due to unexpected eddies and counter-currents at the base of the rocket, dedicated vernier engines were added for extra roll control. The inner six engines were not involved in control. The Block A also included four grid fins, which were later used on Soviet air-to-air missile designs. In total, the Block A produced 45.31 meganewtons (10,190,000 lbf; 4,620,000 kgf) of thrust - Thirty NK-15 engines at 154 metric tons (340,000 lb) thrust each for a total of 4,620 metric tons (10,190,000 lb) liftoff thrust - and this exceeded the 33.7 meganewtons (7,600,000 lbf; 3,440,000 kgf) thrust of the Saturn V. The Saturn V used higher-specific impulse liquid hydrogen fuel in the second and third stages, which eliminated one of the stages needed to get to translunar injection, thus saving weight.
The second stage, Block B, was powered by 8 NK-15V engines arranged in a single ring. The only major difference between the NK-15 and -15V was the engine bell and various tunings for air-start and high-altitude performance. The upper stage, Block V (В/V being the third letter in the Russian alphabet), mounted four smaller NK-21 engines in a square.
During the N1's lifetime, a series of improved engines was introduced to replace those used in the original design. The first stage used an adaptation of the NK-15 known as the NK-33, the second stage a similar modification known as the NK-43, and finally the third stage used the NK-31. The resulting modified N1 was known as the N1F, but did not fly before the project's cancellation.
In comparison with the American Saturn V, the N1 is slightly shorter, more slender overall, but wider at the base. Generally the N1 produced more thrust than the Saturn V. It used only kerosene fuel in all three of its stages, and had lesser overall performance than the Saturn; the N1 stack was intended to place about 95 tonnes (209,000 lb) of payload into low Earth orbit, whereas the Saturn V could orbit about 119 tonnes (262,000 lb). The US's experience with higher energy liquid hydrogen as fuel gave them the confidence to use it on the Saturn upper stages, which significantly reduced the upper stages' take-off weight and increased the payload fraction. The Saturn V also had a superior reliability record: it never lost a payload in 13 operational launches, while four N1 launch attempts all resulted in failure, with one payload loss. (See 6. Launch History, for more details)
Complex plumbing was needed to feed fuel and oxidizer into the clustered arrangement of rocket engines. This proved to be extremely fragile, and was a major factor in the design's launch failures. Furthermore the N1's Baikonur launch complex could not be reached by heavy barge. To allow transport by rail, all the stages had to be broken down and re-assembled. The engines for Block A were only test fired individually and the cluster of 30 engines in Block A was never static test fired as a unit. Blocks B and V were static test fired as complete units. As a result, the complex and destructive vibrational modes (which ripped apart propellant lines and turbines) as well as exhaust plume and fluid dynamic problems (causing vehicle roll, vacuum cavitation, and other problems) in Block A were not discovered and worked out before flight.
As a result of its technical difficulties, in turn due to lack of funding for full-up testing, the N1 never successfully completed a test flight. All four unmanned launches out of 12 planned tests ended in failure, each before first-stage separation. The longest flight lasted 107 seconds, just before first-stage separation. Two test launches occurred in 1969, one in 1971 and the final one in 1972. Mishin continued with the N1F project after the cancellation of plans for a manned moon landing in the hope that the booster would be used to launch a large space station comparable to the US Skylab. The program was suspended in 1974 when Mishin was replaced by Glushko. Two N1Fs, vehicles 8L and 9L, were being readied for launch at the time, but these plans were canceled and the vehicles ordered to be broken up by Glushko in 1976 when the N1 program was formally terminated.
- N1 1M1 - Static test model, two first stages painted gray, third stage gray-white and L3 white.
- N1 1L and 2L - test vehicles
- N1 3L - first launch attempt, engine fire, exploded at 12 km
- N1 4L - never launched, parts used for other launchers
- N1 5L - partially painted gray; early launch failure destroyed pad
- N1 6L - launched from the second pad 110, deficient roll control, destroyed at 1 km
- N1 7L - all white, last launch attempt; engine cutoff at 40 kilometres (22 nmi)
- N1 8L, 9L and 10L
The two flight-ready N1Fs, vehicles 8L and 9L were scrapped and their remains could still be found around Baikonur years later used as shelters and storage sheds. The boosters were deliberately broken up in an effort to cover up the USSR's failed moon attempts, which was publicly stated to be a paper project in order to fool the US into thinking there was a race going on. This cover story lasted until glasnost, when the remaining hardware was seen publicly on display.
The advanced engines for the N1F escaped destruction. Although the rocket as a whole was unreliable, the NK-33 and NK-43 engines are considered rugged and reliable when used as a standalone unit. About 150 engines survived, and in the mid-1990s, Russia sold 36 engines to Aerojet General for $1.1 million each. This company also acquired a license for the production of new engines.
Supplied through Aerojet, three of the engines were incorporated into Japanese rockets J-1 and J-2. The US company Kistler Aerospace worked on incorporating these engines into a new rocket design, with which Kistler sought to eventually offer commercial launch services, before declaring bankruptcy. The Orbital Science's Antares launch vehicle includes two NK-33s as the first-stage engines, first launched in 2013.
In Russia, N1 engines were not used again until 2004, when the remaining 70 or so engines were incorporated into a new rocket design, the Soyuz 3. As of 2005[update], the project has been frozen due to the lack of funding but in that same year RKK Energia proposed replacing the Soyuz-TMA with the Kliper winged spacecraft which was to be launched on a Soyuz 2-3. This proposed launch vehicle was to be powered by a variant of the NK-33 in the core block but used a variant of the RD-120 in the strap-on boosters. There was also a more powerful version of the Soyuz 2-3 launch vehicle proposed that would use the NK-33 variant in the four strap-on boosters as well. The Kliper project has been moribund since 2006. Instead, the NK-33 was incorporated into the first-stage of a light variant of the Soyuz rocket, which was first launched on 28 December 2013.
- February 21, 1969 – Vehicle serial number 3L – Zond L1S-1 (Soyuz 7K-L1S (Zond-M) modification of Soyuz 7K-L1 "Zond" spacecraft) for Moon flyby – Just after liftoff, within the first second, the KORD system (Russian acronym for KOntrol Racketnykh Dvigateley) issued a spurious command to shut down engines number 12 and 24. Nonetheless the N1 continued its flight as Block A was designed to complete a mission with 26 engines. Due to unexpected high-frequency oscillations in the gas generator of engine number 2, one of the pipes broke apart at T+25 seconds and a fire started. This fire reached the KORD engine control system, which at T+68.7 seconds issued a general command to shut down all the functioning 28 engines in Block A. The rocket exploded at 12,200 m altitude, 69 seconds after liftoff. The Safety Assurance System (SAS) was activated and did its job properly, saving the mockup of the spacecraft. All subsequent flights had freon fire extinguishers installed next to every engine.
- July 3, 1969 – Vehicle serial number 5L – First night launch. Zond L1S-2 for Moon orbit and flyby and intended photography of possible manned landing sites – 5–9 seconds after liftoff at 150–200 meters above the pad, a loose bolt was ingested into an oxygen pump, which exploded. The explosion severed the main cables for the KORD system which were located adjacent to that engine, shutting off 29 of the 30 engines, which caused the rocket to fall back towards the pad. The rocket exploded 23 seconds after shutting off the engines, destroying the rocket and launch tower. The destroyed complex was photographed by American satellites, disclosing that the Soviet Union was building a Moon rocket. The rescue system saved the dummy spacecraft again. After this flight, fuel filters were installed in later models. It also took 18 months to rebuild the launch pad and delayed launches. This is one of the largest artificial non-nuclear explosions in human history and was visible that evening 35 kilometres (22 mi) away at Leninsk (See also Tyuratam).
- June 26, 1971 – Vehicle serial number 6L – dummy Soyuz 7K-LOK (Soyuz 7K-L1E No.1) and dummy LK module-spacecraft for Moon flyby – experienced an uncontrolled roll immediately after liftoff beyond the capability of the control system to compensate. The vehicle began to break up as it went through Max Q and was destroyed 51 seconds after liftoff at 1 km altitude by range safety. This vehicle had dummy upper stages without the rescue system. The next, last vehicle would have a much more powerful stabilization system with dedicated engines (in the previous versions stabilization was done by directing exhaust from the main engines). The engine control system would also be reworked, increasing the number of sensors from 700 to over 13,000.
- November 23, 1972 – Vehicle serial number 7L – regular Soyuz 7K-LOK (Soyuz 7K-LOK No.1) and dummy LK module-spacecraft for Moon flyby – the engines ran for 106.93 seconds after which pogo oscillation of the first stage (a problem also encountered on the US Saturn V second and eighth flights, but ultimately solved) caused engine cutoff at 40 kilometres (130,000 ft) altitude moments after a programmed shutdown of the six center engines in the boat-tail, to prevent over-stressing of the structure, led to an explosion of the oxygen pump on engine number 4. The vehicle could have continued its flight if Block A was staged and Block B ignited, but this was not the case and it was destroyed before the second stage, Block B, could begin operation. The SAS fired the payload free, once again saving it from destruction. This N1 was the first Soviet rocket to use a digital guidance and control system called the S-530 computer. (The American Saturn 1B and Saturn V both used a digital telemetry and guidance system.) The telemetry system relayed data back at a rate of 9.6 Gigabytes per second on 320,000 channels on 14 frequencies, so fast that eavesdropping American satellites could not keep up. Commands could be sent to an ascending N1 at the same rate.
- A fifth launch – with the newly upgraded N1F configuation, serial number 8L – was in preparation for August 1974, when the program was cancelled in May 1974. It was scheduled to launch an uncrewed L3 lunar expedition complex for a Moon flyby and landing. The L3 complex included a flight-ready 7K-LOK Soyuz 7K-LOK spacecraft, and an LK lunar module. It was to have tested the planned mission profile that cosmonauts would perform.
Confusion on L3 designation
There is a great deal of confusion among Russian online sources as to whether N1-L3 (Russian: Н1-Л3) or N1-LZ (Russian: Н1-ЛЗ) was intended, because of the similarity of the Cyrillic letter Ze for "Z" and the number "3". Sometimes both forms are used within the same Russian website (or even the same article). English sources refer only to N1-L3. It is clear from the writing of a leading project designer that the correct designation is L3, representing the third stage of Soviet lunar exploration. Stage 1 would be an unmanned circumlunar flight; stage two would be a manned circumlunar flight, and stage 3 would be the manned landing.
|Wikimedia Commons has media related to N-1 (rocket).|
- Zak, Anatoly. "Soviet N1 moon booster". russianspaceweb.com. Anatoly Zak. Retrieved 28 June 2014.
- "N1". Encyclopedia Astronautica. Retrieved 2011-09-07.
- "The N1 Moon Rocket - a brief History". Retrieved 2013-01-01.
- Vick, Charles P. "The Mishin Mission December 1962 - December 1993". Federation of American Scientists. Journal of the British Interplanetary Society, Vol. 47, pp. 357-362, 1994. Retrieved 28 June 2014.
- Chertok, Boris E. (2011). Rockets and people.. Washington, DC: NASA. p. 604. ISBN 978-0-16-089559-3.
- "The Engines That Came In From The Cold". YouTube. Equinox TV. Retrieved 2 July 2014.
- Harvey, Brian (2007). Soviet and Russian lunar exploration. Berlin: Springer. p. 233. ISBN 0387739769. Retrieved 2 July 2014.
- Harvey, Brian (2007). Soviet and Russian lunar exploration. Berlin: Springer. pp. 148–149. ISBN 0387739769.
- Vick, Charles P. "Korelev's Lunar Mission Profile". Federation of American Scientists. SPACEFLIGHT, Vol. 38, 1996. Retrieved 28 June 2014.
- Moltz, James Clay (2011). The politics of space security strategic restraint and the pursuit of national interests (2nd ed. ed.). Stanford, Calif.: Stanford Security Studies. p. 155. ISBN 0804780749. Retrieved 28 June 2014.
- "Soviet race to the Moon". century-of-flight.net. Century of Flight. Retrieved 29 June 2014.
- Lindroos, Marcus. "The Soviet Manned Lunar Program". FAS.org. Federation of American Scientists. Retrieved 29 June 2014.
- Lindroos, Marcus. The Soviet Manned Lunar Program MIT. Accessed: 4 October 2011.
- Johnson, Nicholas L. (1995). The Soviet reach for the moon : the L-1 and L-3 manned lunar programs and the story of the N-1 "Moon Rocket" (2nd ed. ed.). [Washington, D.C.]: Cosmos Books. p. 10. ISBN 1-885609-03-5.
- Barensky, C. Lardier, Stefan (2013). The Soyuz launch vehicle the two lives of an engineering triumph. New York: Springer. p. 137. ISBN 146145459X.
- Wade, Mark. "R-20". astronautix.com. Encyclopedia Astronautica. Retrieved 30 June 2014.
- Zak, Anatoly. "Chronology of the Moon Race". russianspaceweb.com. Russian Space Web. Retrieved 30 June 2014.
- "The N1 History". MoonRace2001.org. Association of Experimental Rocketry of the Pacific. Retrieved 28 June 2014.
- Wade, Mark. "RD-270". astronautix.com. Encyclopedia Astronautica. Retrieved 30 June 2014.
- "RED FILES: Secret Soviet Moon Mission - Interview with James Harford, Sergei P. Korolev's Biographer". PBS.org. Review of Red Files PBS broadcast. 2014 Public Broadcasting Service (PBS). Retrieved 28 June 2014.
- Brügge, Norbert. "Nositel N-1". b14643.de. Norbert Brügge, Germany. Retrieved 28 June 2014.
- Chertok, Boris E. (2011). Rockets and people.. Washington, DC: NASA. p. xxii. ISBN 9780160895593. Retrieved 29 June 2014.
- Wade, Mark. "The N1 Story - Part 2 - N1 with Aerospike First Stage Engines". astronautix.com. Encyclopedia Astronautica. Retrieved 30 June 2014.
- Wade, Mark. "1964.07.19 - Korolev obtains preliminary approval for a single-launch, lunar orbit rendezvous, manned landing.". astronautix.com. Encyclopedia Astronautica. Retrieved 28 June 2014.
- "Tsar Rocket on English Russia - N1 manned lunar launch vehicle history". EnglishRussia.com. English Russia Interesting news from Russia in English language. Retrieved 28 June 2014.
- Wade, Mark. "N1 - Timeline 1966 February 14, N1 redesign to increase payload to 95 tonnes". astronautix.com. Encyclopedia Astronautica. Retrieved 28 June 2014.
- Johnson, Nicholas L. (1995). The Soviet reach for the moon : the L-1 and L-3 manned lunar programs and the story of the N-1 "Moon Rocket" (2nd ed. ed.). [Washington, D.C.]: Cosmos Books. p. 41. ISBN 1-885609-03-5.
- Lux, Boris. "Lux's type collection - N1-L3 launch vehicle". boris-lux.de. 1997-2014 by B.Lux, Hamburg - Germany. Retrieved 29 June 2014.
- "THE N1 HISTORY". MoonRace2001.org. Association of Experimental Rocketry of the Pacific. Retrieved 3 July 2014.
- Chertok, Boris E. (2011). Rockets and people.. Washington, DC: NASA. p. 199. ISBN 978-0-16-089559-3. Retrieved 3 July 2014.
- Wade, Mark (1997–2008). "N1". Encyclopedia Astronautica. Retrieved 2009-04-25.
- Wade, Mark. "NK-15". astronautix.com. Encyclopedia Astronautica. Retrieved 3 July 2014.
- "The N1 History". MoonRace2001.org. Association of Experimental Rocketry of the Pacific. Retrieved 3 July 2014.
- Wade, Mark (1997–2008). "Saturn V". Encyclopedia Astronautica. Retrieved 2009-04-25.
- "Complex N1-L3 - Tests". S.P. Korlev Rocket and Space Corporation Energia - History. 2000 - 2013 Official website of S.P. Korolev RSC "Energia". Retrieved 29 June 2014.
- Clark, Stephen. "Antares rocket engines lean on Russian moon legacy". SpaceFlightNow.com. SPACEFLIGHT NOW April 16, 2013. Retrieved 28 June 2014.
- Harvey, Brian (2007). The rebirth of the Russian space program 50 years after Sputnik, new frontiers (1st ed. ed.). New York: Springer. p. 201. ISBN 0387713565.
- Zak, Anatoly. "The history of the Soyuz-3 launch vehicle.". russianspaceweb.com. Russian Space Web. Retrieved 29 June 2014.
- Barensky, C. Lardier, Stefan (2013). The Soyuz launch vehicle the two lives of an engineering triumph. New York: Springer. p. 182. ISBN 146145459X. Retrieved 19 July 2014.
- Barensky, C. Lardier, Stefan (2013). The Soyuz launch vehicle the two lives of an engineering triumph. New York: Springer. p. 183. ISBN 146145459X.
- "Soyuz 2-1v". Spaceflight 101. Retrieved December 28, 2013.
- "КОНТРОЛЬ РАКЕТНЫХ ДВИГАТЕЛЕЙ - Monitoring the Functioning of the Elements of Rocket Engines". radian-spb.ru. 2014 RADIAN. Retrieved 29 June 2014.
- Zak, Anatoly. "N1 No. 3L launch". Russian Space Web. Anatoly Zak. Retrieved 28 June 2014.
- Raketno-kosmicheskii kompleks N1-L3,book: Гудилин В.Е., Слабкий Л.И. (Слабкий Л.И.)(Gudilin V., Slabkiy L.)"Ракетно-космические системы (История. Развитие. Перспективы)",М.,1996
- Harvey, Brian (2007). Soviet and Russian lunar exploration. Berlin: Springer. p. 222. ISBN 0387739769.
- "Die russische Mondrakete N-1 (in German)".
- Williams, David (6 January 2005), Tentatively Identified Missions and Launch Failures, NASA Goddard Space Flight Center, retrieved 17 May 2013
- Harford, James (1997). Korolev : how one man masterminded the Soviet drive to beat America to the moon. New York ; Chichester: Wiley. ISBN 0471327212.
- Reynolds, David West (2002). Apollo: The Epic Journey to the Moon. San Diego, CA 92121: Tahabi Books. p. 162. ISBN 0-15-100964-3.
- David, Leonard. "New Secrets of Huge Soviet Moon Rocket Revealed". SPACE.com. SPACE.com. Retrieved 29 June 2014.
- Vick, Charles P. "UNMASKING N1-L3 An In-depth Analysis of a Critical Aspect of the Cold War: The Soviet Manned Lunar Programs, from the American and Russian Perspective.". GlobalSecurity.org. Government Printing Office (GPO) Washington DC. Retrieved 28 June 2014.
- Wade, Mark. "1969.07.03 - N1 5L launch". astronautix.com. Encyclopedia Astronautica. Retrieved 28 June 2014.
- Wade, Mark. "N1". astronautix.com. Encyclopedia Astronautica. Retrieved 29 June 2014.
- "Complex N1-L3 - Launches". S.P. Korlev Rocket and Space Corporation Energia. 2000 - 2013 Official website of S.P. Korolev RSC Energia. Retrieved 29 June 2014.
- Wade, Mark. "N1 Manned Lunar Launch Vehicle". astronautix.com. Retrieved 24 June 2014.
- Gainor, Chris (2001). Arrows to the Moon. Burlington, Ontario: Apogee Books. pp. 155–156. ISBN 978-1-896522-83-8.
- Harvey, Brian (2007). Soviet and Russian lunar exploration. Berlin: Springer. p. 226. ISBN 978-0-387-73976-2.
- Lindroos, Marcus. "The Soviet Manned Lunar Program". Federation of American Scientists. Archived from the original on 3 July 2014. Retrieved 29 June 2014.
- В. М. Филин (V.M. Filin), Воспоминания О Лунном Корабле (Memories of the Moon Ship), Издательство "Культура" (publisher "Culture"), 1992, pg. 5
- "The space program L-3 (N1-L3) (Л-3 (Н1-Л3)". Gagarin Research & Test Cosmonaut Training Center. State Organization "Gagarin Research & Test Cosmonaut Training Center" Star city, Moscow region, Russia, 141160. Retrieved 29 June 2014.
- The N-1 Rocket and the Soviet Manned Lunar Program.
- The Engines That Came In From The Cold!, Equinox, Channel Four Television Corporation, 2000. Documentary video on Russian rocket engine development for the N1.
- Astronautix history of the N1
- N-1 Launch Vehicle
- Statistics and information. Interactive model.
- Video footage of an N-1 exploding in flight
- Raketno-kosmicheskii kompleks N1-L3,book: Гудилин В.Е., Слабкий Л.И. (Слабкий Л.И.)(Gudilin V., Slabkiy L.)"Ракетно-космические системы (История. Развитие. Перспективы)",М.,1996 (in Russian)
- Interview with Vasily Pavlovich Mishin (in Russian)
- Orbital Sciences – the U.S. company that developed the Antares Rocket based on an NK-33-powered first stage.
- N1/L3 (11A52) on Gunters Space Page Gunter Dirk Krebs 1996-2014