N1 or
N-1 or
11A52 (Н1, Н-1, 11А52 in Russian) was a secret
SovietThe Union of Soviet Socialist Republics was a constitutionally socialist state that existed in Eurasia from 1922 to 1991. The name is a translation of the , tr. Soyuz Sovetskikh Sotsialisticheskikh Respublik, abbreviated СССР, SSSR. The common short name is Soviet Union, from , Sovetskiy Soyuz...
rocketA rocket or rocket vehicle is a missile, spacecraft, aircraft or other vehicle which obtains thrust by the reaction of the rocket to the ejection of a jet of fast moving fluid exhaust from a rocket engine. Chemical rockets create their exhaust by the combustion of rocket propellant...
intended to send Soviet cosmonauts to the
MoonThe Moon is Earth's only natural satellite and the fifth largest satellite in the Solar System. The average centre-to-centre distance from the Earth to the Moon is , about thirty times the diameter of the Earth. The common centre of mass of the system is located at about —a quarter the Earth's...
. It is also known in the West as the
G-1e or
SL-15. The Soviet classified technical name N1 was an abbreviation from the Russian word
носитель (nositel', "carrier"). 11A52 was an alphanumeric designation for the N1 on its design and production documents. No official public name for the N1, had it succeeded, was ever adopted. N1 was underfunded, undertested, and started several years after the
Saturn VThe Saturn V was a multistage liquid-fuel expendable rocket used by NASA's Apollo and Skylab programs from 1967 until 1973. In total NASA launched thirteen Saturn V rockets with no loss of payload. It remains the largest and most powerful launch vehicle ever brought to operational status from a...
; all four launch attempts failed catastrophically, and the project was cancelled in 1974 de-facto and in 1976 officially. The N1 program (along with the rest of the
Soviet manned moon programsThe Soviet Union competed with the United States to be the first to land a man on the Moon in the 1960s. The Soviet Moonshot program ultimately consisted of two separate manned programs: a lunar flyby program using a UR-500K / L1 combination, and a lunar landing program using a N1 / L3 combination...
) was kept intensely secret until the arrival of
glasnostwas the policy of maximal publicity, openness, and transparency in the activities of all government institutions in the Soviet Union, together with freedom of information, introduced by Mikhail Gorbachev in the second half of 1980s....
. Information about the N1 was published in 1990.
Early work
Development of the N1 began in 1959 under the direction of
Sergey KorolyovSergey Pavlovich Korolyov , , , was the head Soviet rocket engineer and designer during the Space Race between the United States and the Soviet Union in the 1950s and 1960s...
at his
OKB-1OAO S.P. Korolev Rocket and Space Corporation Energia , also known as RKK Energiya, is a Russian manufacturer of spacecraft and space station components...
Design Bureau. The original design proposed a 50 ton payload intended as a launcher for military
space stationA space station is an artificial structure designed for humans to live in outer space. To date, only low earth orbital stations have been implemented, otherwise known as orbital stations...
s 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 ChelomeiVladimir Nikolayevich Chelomey was a Soviet mechanics scientist and rocket engineer.-Early life:Chelomey was born in Siedlce, Russian Empire into a Ukrainian family...
's proposed
UR-200The UR-200 was an intercontinental ballistic missile developed by OKB-52 of Vladimir Nikolaevich Chelomey in the Soviet Union. It was known during the Cold War by the NATO reporting name SS-10 Scrag and internally by the GRAU index 8K81...
, and the much smaller N3, which would replace Korolyov's "workhorse" R-7 rocket. No actual development was carried out at this point, however, the N-series was strictly a "paper project".
In December 1959 a meeting was called with all of the chief designers, who presented their latest designs to the military. Korolev presented the N-series along with a much more modest series of upgrades to the R-7.
Vladimir ChelomeiVladimir Nikolayevich Chelomey was a Soviet mechanics scientist and rocket engineer.-Early life:Chelomey was born in Siedlce, Russian Empire into a Ukrainian family...
, Korolev's rival, presented his "Universal Rocket" series, which used a common lower stage in various clustered configurations to meet a wide variety of payload requirements.
Mikhail YangelMikhail Kuzmich Yangel was a leading missile designer in the Soviet Union....
, perhaps the most successful of the three but with little political power, presented the small R-26 intended to replace the R-16, the much larger R-36 ICBM, as well as the SK-100, a space launcher based on a huge cluster of R-16's. In the end the military planners selected Chelomei's
UR-100The UR-100 was an intercontinental ballistic missile developed and deployed by the Soviet Union from 1966 to 1996. УР in its designation stands for "универсальная ракета"...
as the new "light" ICBM, and Yangel's R-36 for the "heavy" role. They saw no need for any of the larger dedicated launchers, but also gave Korolev funding to develop the
MolniyaMolniya 8K78 was a modification of the well-known R-7 Semyorka rocket and has four stages.This derivative of the original three stage Vostok rocket was especially designed to bring high flying satellites into orbit or to launch probes to other planets. The first launch of this rocket was on...
(8K78) adaptation of the R-7.
Things changed in 1961. In March, during a meeting at
BaikonurBaikonur , formerly known as Leninsk, is a city in Kyzylorda Province of Kazakhstan, rented and administered by Russia. It was constructed to service the Baikonur Cosmodrome and was officially renamed Baikonur by Boris Yeltsin on December 20, 1995....
, designers discussed the N1 design, along with a competing
GlushkoValentyn Petrovych Glushko was a Soviet engineer, and one of the three principal Soviet "Chief Designers" of spacecraft and rockets during the Soviet/American Space Race.-Biography:At the age of 13 he became interested in aeronautics after reading novels...
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.
Moon missions
When the US announced the goal of landing a man on the moon in May 1961, Korolev proposed a lunar mission based on a new spacecraft, eventually known as
SoyuzSoyuz ; English: Union) is a series of spacecraft designed for the Soviet space program by the Korolyov Design Bureau. The Soyuz succeeded the Voskhod spacecraft and was originally built as part of the Soviet Manned Lunar program...
, that was designed for
Earth orbit rendezvousEarth orbit rendezvous is type of space rendezvous, a method that has been proposed for space missions to the Moon. NASA considered an EOR mission profile for the Apollo program, but chose instead to use lunar 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-ton payload much smaller than the N1 design that would eventually be delivered.
To power the new design,
Valentin GlushkoValentyn Petrovych Glushko was a Soviet engineer, and one of the three principal Soviet "Chief Designers" of spacecraft and rockets during the Soviet/American Space Race.-Biography:At the age of 13 he became interested in aeronautics after reading novels...
, who then held a near-monopoly on rocket engine design in the Soviet Union, proposed a new engine, the
RD-270RD-270 - is a single chamber liquid bipropellant rocket engine designed by Energomash in 1960-1970. It was to be used on the first stages of proposed heavy-lift UR-700 and UR-900 rocket families. The development of this engine was stopped with all other work on corresponding rocket projects on 11...
, running on unsymmetrical dimethylhydrazine (UDMH) and nitrogen tetroxide (N
2O
4). 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. However, the propellant pair UDMH/N
2O
4 has
specific impulseSpecific impulse is a way to describe the efficiency of rocket and jet engines. It represents the impulse per unit of propellant. The higher the specific impulse, the less propellant is needed to gain a given amount of momentum...
lower than
keroseneKerosene, sometimes spelled kerosine in scientific and industrial usage, also known as paraffin, is a combustible hydrocarbon liquid. The name is derived from Greek keros...
/
liquid oxygenLiquid oxygen is a form of the element oxygen. It has a pale blue color and is strongly paramagnetic and can be suspended between the poles of a powerful horse shoe magnet...
, and Korolev felt that any realistic high-performance design would need to use higher-performance fuels. Even more importantly, Korolev felt that the toxic nature of the fuels and their exhaust presented a real safety risk for manned space flight.
The difference of opinions led to a falling out between Korolev and Glushko. In 1962 a committee that was appointed to break the logjam agreed with Korolev. Since Glushko refused to work on such a design, Korolev eventually "gave up" and decided to enlist the help of
Nikolai KuznetsovKuznetsov was a Soviet design bureau for aircraft engines, led by Nikolai Dmitriyevich Kuznetsov.It first became notable for the monstrous NK-12 turboprop engine that powered the Tupolev Tu-95 bomber in 1952...
, the OKB-276
jet engineA jet engine is a reaction engine that discharges a fast moving jet of fluid to generate thrust in accordance with Newton's laws of motion. This broad definition of jet engines includes turbojets, turbofans, rockets, ramjets, pulse jets and pump-jets...
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-15's 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 augmentationAir-augmented rockets use the supersonic exhaust of some kind of rocket engine to further compress air collected by ram effect during flight to use as additional working mass, leading to greater effective thrust for any given amount of fuel than either the rocket or a ramjet...
, 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 engineThe aerospike engine is a type of rocket engine that maintains its aerodynamic efficiency across a wide range of altitudes through the use of an aerospike nozzle. It is a member of the class of altitude compensating nozzle engines. A vehicle with an aerospike engine uses 25–30% less fuel at low...
system; more conventional aerospike engines were also studied.
Meanwhile, Chelomei's OKB-52 proposed an alternate mission with much lower risk. Instead of a manned landing, Chelomei proposed a series of circumlunar missions which he felt would be able to beat the US. He also proposed a new booster for the mission, clustering three of his existing UR-200 designs (known as the
SS-11SS-11 may refer to:* SS-11 Sego - Soviet intercontinental ballistic missile UR-100* SS.11 - French anti-tank missile...
in the west) to produce a single larger booster, the UR-500. However, these plans were dropped when Glushko offered Chelomei the RD-270, which allowed the construction of a much simpler "monoblock" design, also known as the UR-500. He also proposed adapting an existing spacecraft design for the circumlunar mission, the single-cosmonaut LK-1. Chelomei felt that improvements in early UR-500/LK-1 missions would allow the spacecraft to be adapted for two cosmonauts.
The Soviet military, specifically the Strategic Missile Forces, was reluctant to support what was essentially a politically-motivated project with little military utility. However, both Korolev and Chelomei pushed for a lunar mission. For some time, between 1961 and 1964, Chelomei's less aggressive proposal was accepted, and development of his UR-500 and the LK-1 were given a high priority.
Space race
When
GeminiProject Gemini was the second human spaceflight program of NASA, the civilian space agency of the United States government. Project Gemini operated between Projects Mercury and Apollo, with 10 manned flights occurring in 1965 and 1966...
missions put the US in the lead in space development, Korolev pressured
Nikita KhrushchevNikita Sergeyevich Khrushchev led the Soviet Union during the Cold War. He served as First Secretary of the Communist Party of the Soviet Union from 1953 to 1964, and as Chairman of the Council of Ministers, or Premier, from 1958 to 1964...
into making a lunar landing before the US. Since there were a number of unknowns in the Earth orbit rendezvous profile that could not be tested in time, a
direct ascentDirect ascent was a proposed method for a mission to the Moon. In the United States, direct ascent proposed using the enormous Nova rocket or Saturn C-8 to loft a spacecraft directly to the Moon, where it would land tail-first and then launch off the Moon back to Earth...
profile similar to Apollo was selected. This required much larger boosters.
Korolev proposed a larger N1, combined with a new lunar package known as the
L3The Soyuz 7K-L3 LOK was designed to launch men from Earth to circle the moon and developed in parallel to the 7K-L1. The LOK -Lunniy Orbitalny Korabl would carry two cosmonauts into orbit around the Moon, acting as "mother" spacecraft for the LK Lander, which would land one member of the crew to...
. The L3 combined the lunar engines, an adapted
Soyuz spacecraftSoyuz ; English: Union) is a series of spacecraft designed for the Soviet space program by the Korolyov Design Bureau. The Soyuz succeeded the Voskhod spacecraft and was originally built as part of the Soviet Manned Lunar program...
(the
LOKThe Soyuz 7K-L3 LOK was designed to launch men from Earth to circle the moon and developed in parallel to the 7K-L1. The LOK -Lunniy Orbitalny Korabl would carry two cosmonauts into orbit around the Moon, acting as "mother" spacecraft for the LK Lander, which would land one member of the crew to...
) and the new
LK lunar landerThe LK was a Soviet lunar lander and counterpart of the American Lunar Module . The LK was to have landed a single Soviet citizen on the Moon before the Americans, winning the Moon race...
in a single package. Chelomei responded with a clustered UR-500-derived vehicle, topped with the L1 spacecraft already under development, and a lander of their own design. Korolev's proposal was selected as the winner in August 1964, while Chelomei was told to continue with his circumlunar UR-500/L1 work.
When Khrushchev was overthrown later in 1964, infighting between the two teams started anew. In October 1965 the Soviet government ordered a compromise; the circumlunar mission would be launched on Chelomei's UR-500 using Korolev's Soyuz spacecraft in place of their own Zond design, aiming for a launch in 1967, the 50th anniversary of the Bolshevik Revolution. Korolev, meanwhile, would continue with his original N1-L3 proposal. Korolev had clearly won the argument, but work on the L1 continued anyway, as the Zond.
Korolev died in 1966 due to complications after minor surgery, and the work was taken over by his deputy,
Vasily MishinVasily Pavlovich Mishin was a Soviet engineer and a prominent rocketry pioneer....
. Mishin did not have Korolev's political astuteness or power, a problem that helped lead to the eventual downfall of the N1, and of the lunar mission as a whole.
Description
The N1 was a very large rocket, standing 105 metres tall (345 feet)—among the world's largest launch vehicles, second only to the
Saturn VThe Saturn V was a multistage liquid-fuel expendable rocket used by NASA's Apollo and Skylab programs from 1967 until 1973. In total NASA launched thirteen Saturn V rockets with no loss of payload. It remains the largest and most powerful launch vehicle ever brought to operational status from a...
in height, mass and payload. 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 2788 metric tons (6.1 million lb). The lower three stages were shaped to produce a single truncated cone just over 10 m wide at the base, while the L3 section was cylindrical at about 4.4 m wide. 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 cycleThe staged combustion cycle is a thermodynamic cycle of bipropellant rocket engines. Some of the propellant is burned in a pre-burner and the resulting hot gas is used to power the engine's turbines and pumps...
engines. The control system was primarily based on differential throttling of the engines, the outer ring for pitch and yaw, the inner six on gimballing mounts for roll. The Block A also included four grid fins, which were later used on Soviet
air-to-air missileAn air-to-air missile is a guided missile fired from an aircraft for the purpose of destroying another aircraft. AAMs are typically powered by one or more rocket motors, usually solid fuelled but sometimes liquid fuelled...
designs. In total, the Block A produced of thrust. This exceeded the thrust of the Saturn V.
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, mounted 4 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-33NK-33 and NK-43 were rocket engines designed and built in the late 1960s and early 1970s by the Kuznetsov Design Bureau. They were intended for the ill-fated Soviet N-1 rocket moon shot. The NK-33 engine achieves the highest thrust-to-weight ratio of any Earth-launchable rocket engine, whilst...
, 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 VThe Saturn V was a multistage liquid-fuel expendable rocket used by NASA's Apollo and Skylab programs from 1967 until 1973. In total NASA launched thirteen Saturn V rockets with no loss of payload. It remains the largest and most powerful launch vehicle ever brought to operational status from a...
, the N1 is slightly shorter, more slender overall, but much wider at the base. Generally the N1 produced much more thrust than the Saturn V. However, as it used only
keroseneKerosene, sometimes spelled kerosine in scientific and industrial usage, also known as paraffin, is a combustible hydrocarbon liquid. The name is derived from Greek keros...
fuel in all three of its stages, it had somewhat lesser overall performance than the Saturn; the N1 stack could place about 95 tons of payload into
Low Earth orbitA low Earth orbit is generally defined as an orbit within the locus extending from the Earth’s surface up to an altitude of 2,000 km...
, whereas the Saturn V could orbit about 130 tons. The US's earlier work with
liquid hydrogenLiquid hydrogen is the liquid state of the element hydrogen. Hydrogen is found naturally in the molecular H
2 form....
propellant gave them the confidence to use this higher energy fuel on the Saturn upper stages, which significantly reduced the upper stages' take-off weight and led to a higher
payload fractionIn aerospace engineering, payload fraction is a common term used to characterize the efficiency of a particular design. Payload fraction is calculated by dividing the weight of the payload by the weight of the otherwise empty aircraft when fully fueled...
.
Problems
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. It is interesting to speculate whether or not the cost of developing the Saturn V's
F-1 engineThe F-1 is a rocket engine developed by Rocketdyne and used in the Saturn V. Five F-1 engines were used in the S-IC first stage of each Saturn V, which served as the main launch vehicle in the Apollo program...
is more or less than the cost of working out the problems in a cluster engine like the N1. The Saturn V had its share of plumbing-related development issues while feeding only 5 F-1 engines, so N1's 30-engine cluster was arguably a recipe for disaster. On the other hand getting the F-1 to work was extremely difficult due to issues with combustion instability.
Also, 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. As a result, the complex and destructive vibrational modes (which ripped apart propellant lines and turbines) as well as exhaust plume fluid dynamic problems (causing vehicle roll, vacuum cavitation, and other problems) 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 1st 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 stationA space station is an artificial structure designed for humans to live in outer space. To date, only low earth orbital stations have been implemented, otherwise known as orbital stations...
comparable to the US
SkylabSkylab was the United States' first space station, and the second space station visited by a human crew. It was also the only space station NASA launched alone...
. The program was terminated in 1974 when Mishin was replaced, ironically, by Glushko. Two N1F's were being readied for launch at the time, but these plans were cancelled.
The program was followed by the "Vulkan" concept for a huge Proton-like hypergolic-fueled vehicle, and then in 1976 by the commencement of the
EnergiaEnergia was a Soviet rocket that was designed by NPO Energia to serve as a heavy-lift expendable launch system as well as a booster for the Buran Space Shuttle. It had the capacity to place about 88 metric tons in Low Earth orbit....
/Buran program.
Remains
The two flight-ready N1Fs 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
glasnostwas the policy of maximal publicity, openness, and transparency in the activities of all government institutions in the Soviet Union, together with freedom of information, introduced by Mikhail Gorbachev in the second half of 1980s....
, when the remaining hardware was seen publicly on display.
More interestingly, the advanced engines for the N1F escaped destruction. Although the spacecraft as a whole was unreliable, the
NK-33NK-33 and NK-43 were rocket engines designed and built in the late 1960s and early 1970s by the Kuznetsov Design Bureau. They were intended for the ill-fated Soviet N-1 rocket moon shot. The NK-33 engine achieves the highest thrust-to-weight ratio of any Earth-launchable rocket engine, whilst...
and NK-43 engines are considered rugged and reliable when used as a standalone unit. About 150 engines survived, and in the mid-1990s,
RussiaRussia , officially known as both Russia and the Russian Federation , is a country in northern Eurasia . It is a semi-presidential republic, comprising 83 federal subjects...
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-1The J-I was a solid rocket expendable launch vehicle from Japan. It flew only once, in 1996, in a partial configuration, to launch the demonstrator Hyflex. The vehicle never flew in the final orbital capability configuration, which should have launched the OICETS satellite ....
and J-2. The US company Kistler Aerospace continues to work on incorporating these engines into a new rocket design, with which Kistler seeks to eventually offer commercial launch services. In
RussiaRussia , officially known as both Russia and the Russian Federation , is a country in northern Eurasia . It is a semi-presidential republic, comprising 83 federal subjects...
, N1 engines were not used again until 2004, when the remaining 70 or so engines were incorporated into a new rocket design. , the project has been frozen due to the lack of funding. However, the current design of Orbital Science's Taurus II launch vehicle includes two NK-33s as the first stage engines.
Launch history
- February 21 1969: Due to unexpected high-frequency oscillations in the gas generator, one of the pipes broke apart and a fire started. This fire reached the engine control system which at the 68.7 s of flight sent the command to shut down the engines. The rocket exploded at 12,200 m altitude, 69 seconds after liftoff. The emergency rescue system 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: At liftoff a loose bolt was ingested into a fuel pump, which failed. After detecting the inoperative fuel pump, the automatic engine control shut off 29 of 30 engines, which caused the rocket to stall. The rocket exploded 23 seconds after shutting off the engines, destroying the rocket and launch tower in the biggest explosion in the history of rocketry.. 2,600 tons of fuel had the power of the small nuclear bomb. 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.
- June 27 1971: Vehicle serial number 6L experienced an uncontrolled roll immediately after liftoff beyond the capability of the control system to compensate; the vehicle was destroyed 51 seconds after liftoff at 1 km altitude. This vehicle had dummy upper stages without the rescue system. The next, last vehicle had 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 was also reworked, increasing the number of sensors from 700 to 13,000.
- November 23 1972: Vehicle serial number 7L the engines ran for 106.93 seconds after which Pogo oscillation
Pogo oscillation is a potentially dangerous type of self-excited oscillation caused by combustion instability in liquid fuel rocket engines. This oscillation results in variations of thrust from the engines, generally caused by variations in fuel flow rate, and placing stress on the frame of the...
of the first stage caused engine cutoff at 40 km altitude; a programmed shutdown of some of the engines to prevent over-stressing of the structure led to an explosion of the oxygen pump on the engine number 4. The vehicle disintegrated.
Confusion on designation
The overall rocket system actually bore the designation N1-L3: N1 was the booster, while the L3 was mounted on top for the trip to lunar orbit and, it was hoped, lunar landing. There is a great deal of confusion among Russian online sources as to whether it is N1-L3 (Russian: Н1-Л3) or N1-LZ (Russian: Н1-ЛЗ) because of the similarity of the
CyrillicThe Cyrillic script writing system isan alphabet developed in the First Bulgarian Empire, and used in the Slavic national languages of Russian, Bulgarian, Belarusian, Rusyn, Serbian, Macedonian, and Ukrainian, and in the non-Slavic languages of Moldovan, Kazakh, Uzbek, Kyrgyz, Tajik, Tuvan, and...
letter
ZeZe is a letter of the Cyrillic alphabet, representing the consonant . It's easily confusable with the figure three and the Russian letter Э, which represents the vowel when it does not follow a soft consonant....
for "Z" and the number "3". Sometimes both forms will be used within the same Russian website (or even the same article). However, English sources refer only to N1-L3, and it seems clear it is a number because there were lunar projects with code names from L1 to L5.
See also
- Comparison of heavy lift launch systems
When comparing launch systems, those capable of lifting the most mass to orbit use Heavy Lift Launch Vehicles. The phrase "heavy lift" has often been applied to vehicles like Saturn V, Titan IV, Ariane 5, Proton, and Delta IV-Heavy...
- Soviet Moonshot
The Soviet Union competed with the United States to be the first to land a man on the Moon in the 1960s. The Soviet Moonshot program ultimately consisted of two separate manned programs: a lunar flyby program using a UR-500K / L1 combination, and a lunar landing program using a N1 / L3 combination...
External links