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36-553: The company develops and manufactures spacecraft such as the Fregat rocket upper stages, satellites and interplanetary probes. It is a contractor for a number of military programs, such as the Oko early warning satellite , Prognoz and Araks programmes as well as the civilian program Kupon . One of the company's most notable projects was the participation in the failed Fobos-Grunt sample return mission . NPO Lavochkin has also developed

72-601: A petroleum benzine to a spark plug for ignition, with the engine putting out 300 pulsating explosions per minute. Paulet would go on to visit the German rocket association Verein für Raumschiffahrt (VfR) and on March 15, 1928, Valier applauded Paulet's liquid-propelled rocket design in the VfR publication Die Rakete , saying the engine had "amazing power". Paulet would soon be approached by Nazi Germany to help develop rocket technology, though he refused to assist and never shared

108-425: A so-called dissociating gas. "Cool" dinitrogen tetroxide is compressed and heated, causing it to dissociate into nitrogen dioxide at half the molecular weight. This hot nitrogen dioxide is expanded through a turbine, cooling it and lowering the pressure, and then cooled further in a heat sink, causing it to recombine into nitrogen tetroxide at the original molecular weight. It is then much easier to compress to start

144-493: A success rate of 97.3%—including two failures and one partial failure—the Fregat is among the most reliable upper stages worldwide. It has successfully deployed over 300 payloads into various orbits and is the only upper stage capable of placing payloads into three or more distinct orbits in a single launch. The Fregat upper stage is designed for injecting large payloads into a low, medium-height or high geosynchronous orbit. Fregat

180-559: Is a hypergolic propellant in combination with a hydrazine -based rocket fuel . One of the earliest uses of this combination was on the Titan family of rockets used originally as ICBMs and then as launch vehicles for many spacecraft. Used on the U.S. Gemini and Apollo spacecraft and also on the Space Shuttle , it continues to be used as station-keeping propellant on most geo-stationary satellites, and many deep-space probes. It

216-451: Is a versatile upper stage; in addition to orbital insertion, it can be used as an escape stage to send modern space probes into interplanetary trajectories (e.g. Venus Express and Mars Express ). Fregat stages are currently used as the fourth stage of some Soyuz launch vehicles. The stage can be restarted up to 7 times. NPO Lavochkin has built many interplanetary probes, and the Fregat stage follows their design traditions. The main part of

252-401: Is also the primary oxidizer for Russia's Proton rocket . When used as a propellant, dinitrogen tetroxide is usually referred to simply as nitrogen tetroxide and the abbreviation NTO is extensively used. Additionally, NTO is often used with the addition of a small percentage of nitric oxide , which inhibits stress-corrosion cracking of titanium alloys, and in this form, propellant-grade NTO

288-445: Is independent from lower stages, since it has its own guidance, navigation, attitude control, tracking, and telemetry systems. The Fregat uses storable propellants (UDMH/ NTO ) and can be restarted up to 7 times in flight – enabling it to carry out complex mission profiles. It can provide three-axis or spin stabilization of the spacecraft payload. The Arianespace -operated flight of a Fregat MT ended in failure on 22 August 2014 after

324-494: Is manufactured on a large scale via N 2 O 4 . This species reacts with water to give both nitrous acid and nitric acid : The coproduct HNO 2 upon heating disproportionates to NO and more nitric acid. When exposed to oxygen, NO is converted back into nitrogen dioxide: The resulting NO 2 and N 2 O 4 can be returned to the cycle to give the mixture of nitrous and nitric acids again. N 2 O 4 undergoes molecular autoionization to give [NO ] [NO 3 ], with

360-674: Is only subject to prior requests. Fregat Fregat ( Russian : Фрегат , lit.   ' frigate ') is an upper stage developed by NPO Lavochkin in the 1990s. It has been used in some Soyuz and Zenit launch vehicles, but is universal and can be used as a part of a medium and heavy class launch vehicles. Fregat became operational in February 2000. Its liquid propellant engine uses unsymmetrical dimethylhydrazine (UDMH) fuel and dinitrogen tetroxide ( N 2 O 4 , also called NTO or amyl) oxidizer. These hypergolic propellants ignite spontaneously upon contact. With

396-419: Is planar with an N-N bond distance of 1.78   Å and N-O distances of 1.19   Å. The N-N distance corresponds to a weak bond, since it is significantly longer than the average N-N single bond length of 1.45   Å. This exceptionally weak σ bond (amounting to overlapping of the sp hybrid orbitals of the two NO 2 units ) results from the simultaneous delocalization of the bonding electron pair across

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432-562: Is referred to as mixed oxides of nitrogen ( MON ). Most spacecraft now use MON instead of NTO; for example, the Space Shuttle reaction control system used MON3 (NTO containing 3% NO by weight). On 24 July 1975, NTO poisoning affected three U.S. astronauts on the final descent to Earth after the Apollo-Soyuz Test Project flight. This was due to a switch accidentally left in the wrong position, which allowed

468-545: Is the chemical compound N 2 O 4 . It is a useful reagent in chemical synthesis. It forms an equilibrium mixture with nitrogen dioxide . Its molar mass is 92.011 g/mol. Dinitrogen tetroxide is a powerful oxidizer that is hypergolic (spontaneously reacts) upon contact with various forms of hydrazine , which has made the pair a common bipropellant for rockets. Dinitrogen tetroxide could be regarded as two nitro groups (-NO 2 ) bonded together. It forms an equilibrium mixture with nitrogen dioxide . The molecule

504-435: Is then purified and condensed to form dinitrogen tetroxide. Nitrogen tetroxide is used as an oxidizing agent in one of the most important rocket propellant systems because it can be stored as a liquid at room temperature. Pedro Paulet , a Peruvian polymath , reported in 1927 that he had experimented in the 1890s with a rocket engine that used spring-loaded nozzles that periodically introduced vaporized nitrogen tetroxide and

540-556: The Elektro–L series of new-generation weather satellites, as well as the Navigator standardised satellite platform, which will serve as the basis for several future Russian satellites. The company was founded in 1937 as OKB-301 , a Soviet aircraft design bureau (OKB). The head designer was Vladimir P. Gorbunov  [ ru ] , supported by Mikhail Gudkov  [ ru ] and Semyon Lavochkin . In October 1945 Lavochkin

576-574: The Lunokhod program , Vega program , Phobos program , etc. The former OKB-301 became named NPO Lavochkin . In January 2012, officials of Lavochkin faced administrative punishment for not taking into account of designing the computer system after the crash of Russia's Mars moon spacecraft Fobos-Grunt . The S. A. Lavochkin NGO has its own museum. It was founded on June 25, 1965. Museum address: 24 Leningradskaya str., Khimki, Moscow region, 141400. The visit

612-414: The attitude control thrusters to fire after the cabin fresh air intake was opened, allowing NTO fumes to enter the cabin. One crew member lost consciousness during descent. Upon landing, the crew was hospitalized for five days for chemical-induced pneumonia and edema . The tendency of N 2 O 4 to reversibly break into NO 2 has led to research into its use in advanced power generation systems as

648-585: The Fregat-SB (including SBB) is 1,410 kg (3,110 lb) and the maximum propellant carrying capacity is 10,150 kg (22,380 lb). Fregat-SB was launched for the first time on 20 January 2011, when it lifted the Elektro-L weather satellite into geosynchronous orbit. Dinitrogen tetroxide Dinitrogen tetroxide , commonly referred to as nitrogen tetroxide ( NTO ), and occasionally (usually among ex-USSR/Russian rocket engineers) as amyl ,

684-509: The Guiana Space Centre ongoing ESA programme. In July 2017, a Russian-operated rideshare flight of a Fregat upper stage ended with 9 of 72 small satellites dead-on-orbit. The Russian-operated flight of a Fregat upper stage ended in failure after the vehicle deposited the upper stage, a Meteor MS-1 weather satellite , and 18 secondary cubesats back into Earth's atmosphere due to the first Fregat burn being ignited with

720-483: The Russian Spektr-R satellite into orbit in 2011, broke into multiple pieces on May 8, 2020 creating even more debris than normal. Fregat-M/Fregat-MT tanks have ball-shaped additions on the tops of the tanks. These additions increase the load capability of the propellant from 5,350 kilograms (11,790 lb) to 6,640 kilograms (14,640 lb), without causing any other changes to the physical dimensions of

756-568: The anhydrous transition metal nitrates have striking colours. This branch of chemistry was developed by Cliff Addison and Norman Logan at the University of Nottingham in the UK during the 1960s and 1970s when highly efficient desiccants and dry boxes started to become available. In even slightly basic solvents, N 2 O 4 adds to alkenes radically, giving mixtures of nitro compounds and nitrite esters . Pure or in entirely nonbasic solvents,

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792-414: The causes of the "anomaly" announced its definitive conclusions on 7 October 2014 following a meeting at Arianespace headquarters in Évry , near Paris . The failure occurred during the flight of the Fregat fourth stage. It occurred about 35 minutes after liftoff, at the beginning of the ballistic phase preceding the second ignition of this stage. The scenario that led to an error in the orbital injection of

828-474: The entire cycle again. Such dissociative gas Brayton cycles have the potential to considerably increase efficiencies of power conversion equipment. The high molecular weight and smaller volumetric expansion ratio of nitrogen dioxide compared to steam allows the turbines to be more compact. N 2 O 4 was the main component of the "nitrin" working fluid in the decommissioned Pamir-630D portable nuclear reactor which operated from 1985 to 1987. Nitric acid

864-490: The equilibrium towards nitrogen dioxide. Inevitably, some dinitrogen tetroxide is a component of smog containing nitrogen dioxide. Solid N 2 O 4 is white, and melts at −11.2 °C. Nitrogen tetroxide is made by the catalytic oxidation of ammonia (the Ostwald process ): steam is used as a diluent to reduce the combustion temperature. In the first step, the ammonia is oxidized into nitric oxide : Most of

900-412: The former nitrosonium ion being a strong oxidant. Various anhydrous transition metal nitrate complexes can be prepared from N 2 O 4 and base metal. where M = Cu , Zn , or Sn . If metal nitrates are prepared from N 2 O 4 in completely anhydrous conditions, a range of covalent metal nitrates can be formed with many transition metals. This is because there is a thermodynamic preference for

936-520: The formula for his propellant. In early 1944, research on the usability of dinitrogen tetroxide as an oxidizing agent for rocket fuel was conducted by German scientists, although the Germans only used it to a very limited extent as an additive for S-Stoff (fuming nitric acid). It became the storable oxidizer of choice for many rockets in both the United States and USSR by the late 1950s. It

972-494: The nitrate ion to bond covalently with such metals rather than form an ionic structure. Such compounds must be prepared in anhydrous conditions, since the nitrate ion is a much weaker ligand than water, and if water is present the simple nitrate of the hydrated metal ion will form. The anhydrous nitrates concerned are themselves covalent, and many, e.g. anhydrous copper nitrate , are volatile at room temperature. Anhydrous titanium nitrate sublimes in vacuum at only 40 °C. Many of

1008-458: The reaction of concentrated nitric acid and metallic copper. This synthesis is practical in a laboratory setting. Dinitrogen tetroxide can also be produced by heating metal nitrates. The oxidation of copper by nitric acid is a complex reaction forming various nitrogen oxides of varying stability which depends on the concentration of the nitric acid, presence of oxygen, and other factors. The unstable species further react to form nitrogen dioxide which

1044-464: The satellites was precisely reconstructed, as follows: The root cause of the failure of flight VS09 is therefore a shortcoming in the system thermal analysis performed during stage design, and not an operator error during stage assembly. Since 22 August 2014, Soyuz ST-B launch vehicles with Fregat-MT upper stages have performed three successful launches, six Galileo navigation satellites have been inserted into their target orbits in frame of Soyuz at

1080-524: The stage in the wrong orientation. The guidance computer on the Soyuz rocket's Fregat upper stage was mis-programmed, causing it to begin an unnecessary turn that left it in the wrong orientation for a critical engine burn required to enter orbit. The Fregats did not have enough impulse capability to de-orbit themselves after placing their payload into orbit and so several have remained in orbit as space debris . The Fregat-SB upper stage rocket used to launch

1116-425: The stage is six intersecting spheres placed on a single plane, four of which contain propellants. The remaining two contain the control equipment. The main engine is placed between the spheres, so Fregat is a tightly-packed stage with a diameter much larger than its height. A set of eight struts through the tanks provide an attachment point for the payload, and also transfer thrust loads to the launcher. The Fregat stage

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1152-546: The vehicle deposited two EU / ESA Galileo navigation satellites into the wrong orbit. The lift off at 12:27:11 UTC from the Sinnamary launch site near Kourou , French Guiana , appeared to go well. However, a failure was only apparent later when, after the second firing of the Fregat MT upper stage had taken place, the satellites were detected as being in the wrong orbit. The Independent Inquiry Board formed to analyze

1188-454: The vehicle. A version called Fregat-SB can be used with Zenit-2SB launch vehicle. This version is a variation of Fregat-M with a block of drop-off tanks ("SBB" or Сбрасываемый Блок Баков in Russian) which makes increased payload capability possible. The torus-shaped SBB weighs 360 kg (790 lb) and contains up to 3,050 kg (6,720 lb) of propellant. The total dry weight of

1224-409: The water is condensed out, and the gases are further cooled; the nitric oxide that was produced is oxidized to nitrogen dioxide, which is then dimerized into nitrogen tetroxide: and the remainder of the water is removed as nitric acid . The gas is essentially pure nitrogen dioxide, which is condensed into dinitrogen tetroxide in a brine-cooled liquefier. Dinitrogen tetroxide can also be made through

1260-399: The whole N 2 O 4 molecule, and the considerable electrostatic repulsion of the doubly occupied molecular orbitals of each NO 2 unit. Unlike NO 2 , N 2 O 4 is diamagnetic since it has no unpaired electrons. The liquid is also colorless but can appear as a brownish yellow liquid due to the presence of NO 2 according to the following equilibrium: Higher temperatures push

1296-517: Was promoted for the head designer of the design bureau. The bureau gained distinction for its family of piston-engined fighter aircraft during World War II, and later shifted to missile and jet fighter designs. Following the death of the head designer, the OKB-301 succumbed to the growing power of Vladimir Chelomey and became OKB-52 Branch No. 3 on 18 December 1962. Later, it turned to work on interplanetary probe designs for Luna sample return program,

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