Liquid rocket propellant

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The highest specific impulse chemical rockets use liquid propellants (liquid-propellant rockets). They can consist of a single chemical (a monopropellant) or a mix of two chemicals, called bipropellants. Bipropellants can further be divided into two categories; hypergolic propellants, which ignite when the fuel and oxidizer make contact, and non-hypergolic propellants which require an ignition source. [1]

Contents

About 170 different propellants made of liquid fuel have been tested, excluding minor changes to a specific propellant such as propellant additives, corrosion inhibitors, or stabilizers. In the U.S. alone at least 25 different propellant combinations have been flown. [2]

Many factors go into choosing a propellant for a liquid-propellant rocket engine. The primary factors include ease of operation, cost, hazards/environment and performance.[ citation needed ]

History

Development in early 20th century

Robert H. Goddard on March 16, 1926, holding the launching frame of the first liquid-fueled rocket Goddard and Rocket.jpg
Robert H. Goddard on March 16, 1926, holding the launching frame of the first liquid-fueled rocket

Konstantin Tsiolkovsky proposed the use of liquid propellants in 1903, in his article Exploration of Outer Space by Means of Rocket Devices. [3] [4]

On March 16, 1926, Robert H. Goddard used liquid oxygen (LOX) and gasoline as propellants for his first partially successful liquid-propellant rocket launch. Both propellants are readily available, cheap and highly energetic. Oxygen is a moderate cryogen as air will not liquefy against a liquid oxygen tank, so it is possible to store LOX briefly in a rocket without excessive insulation. [ clarification needed ]

In Germany, engineers and scientists began building and testing liquid propulsion rockets in the late 1920s. [5] According to Max Valier, two liquid-propellant Opel RAK rockets were launched in Rüsselsheim on April 10 and April 12, 1929. [6]

World War II era

Germany had very active rocket development before and during World War II, both for the strategic V-2 rocket and other missiles. The V-2 used an alcohol/LOX liquid-propellant engine, with hydrogen peroxide to drive the fuel pumps. [7] :9 The alcohol was mixed with water for engine cooling. Both Germany and the United States developed reusable liquid-propellant rocket engines that used a storeable liquid oxidizer with much greater density than LOX and a liquid fuel that ignited spontaneously on contact with the high density oxidizer.[ citation needed ]

The major manufacturer of German rocket engines for military use, the HWK firm, [8] manufactured the RLM-numbered 109-500-designation series of rocket engine systems, and either used hydrogen peroxide as a monopropellant for Starthilfe rocket-propulsive assisted takeoff needs; [9] or as a form of thrust for MCLOS-guided air-sea glide bombs; [10] and used in a bipropellant combination of the same oxidizer with a fuel mixture of hydrazine hydrate and methyl alcohol for rocket engine systems intended for manned combat aircraft propulsion purposes. [11]

The U.S. engine designs were fueled with the bipropellant combination of nitric acid as the oxidizer; and aniline as the fuel. Both engines were used to power aircraft, the Me 163 Komet interceptor in the case of the Walter 509-series German engine designs, and RATO units from both nations (as with the Starthilfe system for the Luftwaffe) to assist take-off of aircraft, which comprised the primary purpose for the case of the U.S. liquid-fueled rocket engine technology - much of it coming from the mind of U.S. Navy officer Robert Truax. [12]

1950s and 1960s

During the 1950s and 1960s there was a great burst of activity by propellant chemists to find high-energy liquid and solid propellants better suited to the military. Large strategic missiles need to sit in land-based or submarine-based silos for many years, able to launch at a moment's notice. Propellants requiring continuous refrigeration, which cause their rockets to grow ever-thicker blankets of ice, were not practical. As the military was willing to handle and use hazardous materials, a great number of dangerous chemicals were brewed up in large batches, most of which wound up being deemed unsuitable for operational systems.[ citation needed ] In the case of nitric acid, the acid itself (HNO
3
) was unstable, and corroded most metals, making it difficult to store. The addition of a modest amount of nitrogen tetroxide, N
2
O
4
, turned the mixture red and kept it from changing composition, but left the problem that nitric acid corrodes containers it is placed in, releasing gases that can build up pressure in the process. The breakthrough was the addition of a little hydrogen fluoride (HF), which forms a self-sealing metal fluoride on the interior of tank walls that Inhibited Red Fuming Nitric Acid. This made "IRFNA" storeable.

Propellant combinations based on IRFNA or pure N
2
O
4
as oxidizer and kerosene or hypergolic (self igniting) aniline, hydrazine or unsymmetrical dimethylhydrazine (UDMH) as fuel were then adopted in the United States and the Soviet Union for use in strategic and tactical missiles. The self-igniting storeable liquid bi-propellants have somewhat lower specific impulse than LOX/kerosene but have higher density so a greater mass of propellant can be placed in the same sized tanks. Gasoline was replaced by different hydrocarbon fuels, [7] for example RP-1   a highly refined grade of kerosene. This combination is quite practical for rockets that need not be stored.

Kerosene

The V-2 rockets developed by Nazi Germany used LOX and ethyl alcohol. One of the main advantages of alcohol was its water content, which provided cooling in larger rocket engines. Petroleum-based fuels offered more power than alcohol, but standard gasoline and kerosene left too much soot and combustion by-products that could clog engine plumbing. In addition, they lacked the cooling properties of ethyl alcohol.

During the early 1950s, the chemical industry in the US was assigned the task of formulating an improved petroleum-based rocket propellant which would not leave residue behind and also ensure that the engines would remain cool. The result was RP-1, the specifications of which were finalized by 1954. A highly refined form of jet fuel, RP-1 burned much more cleanly than conventional petroleum fuels and also posed less of a danger to ground personnel from explosive vapours. It became the propellant for most of the early American rockets and ballistic missiles such as the Atlas, Titan I, and Thor. The Soviets quickly adopted RP-1 for their R-7 missile, but the majority of Soviet launch vehicles ultimately used storable hypergolic propellants. As of 2017, it is used in the first stages of many orbital launchers.

Hydrogen

Many early rocket theorists believed that hydrogen would be a marvelous propellant, since it gives the highest specific impulse. It is also considered the cleanest when oxidized with oxygen because the only by-product is water. Steam reforming of natural gas is the most common method of producing commercial bulk hydrogen at about 95% of the world production [13] [14] of 500 billion m3 in 1998. [15] At high temperatures (700–1100 °C) and in the presence of a metal-based catalyst (nickel), steam reacts with methane to yield carbon monoxide and hydrogen.

Hydrogen is very bulky compared to other fuels; it is typically stored as a cryogenic liquid, a technique mastered in the early 1950s as part of the hydrogen bomb development program at Los Alamos. Liquid hydrogen can be stored and transported without boil-off, by using helium as a cooling refrigerant, since helium has an even lower boiling point than hydrogen. Hydrogen is lost via venting to the atmosphere only after it is loaded onto a launch vehicle, where there is no refrigeration. [16]

In the late 1950s and early 1960s it was adopted for hydrogen-fuelled stages such as Centaur and Saturn upper stages.[ citation needed ] Hydrogen has low density even as a liquid, requiring large tanks and pumps; maintaining the necessary extreme cold requires tank insulation. This extra weight reduces the mass fraction of the stage or requires extraordinary measures such as pressure stabilization of the tanks to reduce weight. (Pressure stabilized tanks support most of the loads with internal pressure rather than with solid structures, employing primarily the tensile strength of the tank material.[ citation needed ])

The Soviet rocket programme, in part due to a lack of technical capability, did not use liquid hydrogen as a propellant until the Energia core stage in the 1980s.[ citation needed ]

Upper stage use

The liquid-rocket engine bipropellant liquid oxygen and hydrogen offers the highest specific impulse for conventional rockets. This extra performance largely offsets the disadvantage of low density, which requires larger fuel tanks. However, a small increase in specific impulse in an upper stage application can give a significant increase in payload-to-orbit mass. [17]

Comparison to kerosene

Launch pad fires due to spilled kerosene are more damaging than hydrogen fires, for two main reasons:

Kerosene fires unavoidably cause extensive heat damage that requires time-consuming repairs and rebuilding. This is most frequently experienced by test stand crews involved with firings of large, unproven rocket engines.

Hydrogen-fuelled engines require special design, such as running propellant lines horizontally, so that no "traps" form in the lines, which would cause pipe ruptures due to boiling in confined spaces. (The same caution applies to other cryogens such as liquid oxygen and liquid natural gas (LNG).) Liquid hydrogen fuel has an excellent safety record and performance that is well above all other practical chemical rocket propellants.

Lithium and fluorine

The highest-specific-impulse chemistry ever test-fired in a rocket engine was lithium and fluorine, with hydrogen added to improve the exhaust thermodynamics (all propellants had to be kept in their own tanks, making this a tripropellant). The combination delivered 542 s specific impulse in vacuum, equivalent to an exhaust velocity of 5320 m/s. The impracticality of this chemistry highlights why exotic propellants are not actually used: to make all three components liquids, the hydrogen must be kept below −252 °C (just 21 K), and the lithium must be kept above 180 °C (453 K). Lithium and fluorine are both extremely corrosive. Lithium ignites on contact with air, and fluorine ignites most fuels on contact, including hydrogen. Fluorine and the hydrogen fluoride (HF) in the exhaust are very toxic, which makes working around the launch pad difficult, damages the environment, and makes getting a launch license more difficult. Both lithium and fluorine are expensive compared to most rocket propellants. This combination has therefore never flown. [18]

During the 1950s, the Department of Defense proposed lithium/fluorine as ballistic-missile propellants. A 1954 accident at a chemical works that released a cloud of fluorine into the atmosphere convinced them to use LOX/RP-1 instead.[ citation needed ]

Methane

Using liquid methane and liquid oxygen as propellants is sometimes called methalox propulsion. [19] Liquid methane has a lower specific impulse than liquid hydrogen, but is easier to store due to its higher boiling point and density, as well as its lack of hydrogen embrittlement. It also leaves less residue in the engines compared to kerosene, which is beneficial for reusability. [20] [21] In addition, it is expected that its production on Mars will be possible via the Sabatier reaction. In NASA's Mars Design Reference Mission 5.0 documents (between 2009 and 2012), liquid methane/LOX (methalox) was the chosen propellant mixture for the lander module.

Due to the advantages methane fuel offers, some private space launch providers aimed to develop methane-based launch systems during the 2010s and 2020s. The competition between countries was dubbed the Methalox Race to Orbit, with the LandSpace's Zhuque-2 methalox rocket becoming the first to reach orbit. [22] [23] [24]

As of January 2024, two methane-fueled rockets have reached orbit. Several others are in development and two orbital launch attempts failed:

SpaceX developed the Raptor engine for its Starship super-heavy-lift launch vehicle. [28] It has been used in test flights since 2019. SpaceX had previously used only RP-1/LOX in their engines.

Blue Origin developed the BE-4 LOX/LNG engine for their New Glenn and the United Launch Alliance Vulcan Centaur. The BE-4 provides 2,400 kN (550,000 lbf) of thrust. Two flight engines had been delivered to ULA by mid 2023.

In July 2014, Firefly Space Systems announced plans to use methane fuel for their small satellite launch vehicle, Firefly Alpha with an aerospike engine design. [29]

ESA is developing a 980kN methalox Prometheus rocket engine which was test fired in 2023. [30]

Monopropellants

High-test peroxide
High test peroxide is concentrated Hydrogen peroxide, with around 2% to 30% water. It decomposes to steam and oxygen when passed over a catalyst. This was historically used for reaction control systems, due to being easily storable. It is often used to drive Turbopumps, being used on the V2 rocket, and modern Soyuz.
Hydrazine
decomposes energetically to nitrogen, hydrogen, and ammonia (2N2H4 → N2+H2+2NH3) and is the most widely used in space vehicles. (Non-oxidized ammonia decomposition is endothermic and would decrease performance).
Nitrous oxide
decomposes to nitrogen and oxygen.
Steam
when externally heated gives a reasonably modest Isp of up to 190 seconds, depending on material corrosion and thermal limits.

Present use

As of June 2024, liquid fuel combinations in common use:

Kerosene (RP-1) / liquid oxygen (LOX)
Used for the lower stages of the Soyuz-2 boosters, the first stage of Atlas V, and both stages of Electron, Falcon 9, Falcon Heavy, and Firefly Alpha.
Liquid hydrogen (LH) / LOX
Used in the stages of the Space Launch System, New Shepard, H-IIB, GSLV and Centaur.
Liquid methane (LNG) / LOX
Used in both stages of Zhuque-2, Starship (doing nearly orbital test flights), and the first stage of the Vulcan Centaur.
Unsymmetrical dimethylhydrazine (UDMH) or monomethylhydrazine (MMH) / dinitrogen tetroxide (NTO or N
2
O
4
)
Used in three first stages of the Russian Proton booster, Indian Vikas engine for PSLV and GSLV rockets, most Chinese boosters, a number of military, orbital and deep space rockets, as this fuel combination is hypergolic and storable for long periods at reasonable temperatures and pressures.
Hydrazine (N
2
H
4
)
Used in deep space missions because it is storable and hypergolic, and can be used as a monopropellant with a catalyst.
Aerozine-50 (50/50 hydrazine and UDMH)
Used in deep space missions because it is storable and hypergolic, and can be used as a monopropellant with a catalyst.

Table

To approximate Isp at other chamber pressures[ clarification needed ]
Absolute pressure kPa ; atm (psi)Multiply by
6,895 kPa; 68.05 atm (1,000 psi)1.00
6,205 kPa; 61.24 atm (900 psi)0.99
5,516 kPa; 54.44 atm (800 psi)0.98
4,826 kPa; 47.63 atm (700 psi)0.97
4,137 kPa; 40.83 atm (600 psi)0.95
3,447 kPa; 34.02 atm (500 psi)0.93
2,758 kPa; 27.22 atm (400 psi)0.91
2,068 kPa; 20.41 atm (300 psi)0.88

The table uses data from the JANNAF thermochemical tables (Joint Army-Navy-NASA-Air Force (JANNAF) Interagency Propulsion Committee) throughout, with best-possible specific impulse calculated by Rocketdyne under the assumptions of adiabatic combustion, isentropic expansion, one-dimensional expansion and shifting equilibrium. [31] Some units have been converted to metric, but pressures have not.

Definitions

Ve
Average exhaust velocity, m/s. The same measure as specific impulse in different units, numerically equal to specific impulse in N·s/kg.
r
Mixture ratio: mass oxidizer / mass fuel
Tc
Chamber temperature, °C
d
Bulk density of fuel and oxidizer, g/cm3
C*
Characteristic velocity, m/s. Equal to chamber pressure multiplied by throat area, divided by mass flow rate. Used to check experimental rocket's combustion efficiency.

Bipropellants

OxidizerFuelCommentOptimal expansion from 68.05 atm to[ citation needed ]
1 atm0 atm, vacuum
(nozzle area ratio 40:1)
VerTcdC*VerTcdC*
LOX H
2
Hydrolox. Common.38164.1327400.29241644624.8329780.322386
H
2
:Be 49:51
44980.8725580.23283352950.9125890.242850
CH
4
(methane)
Methalox . Many engines under development in the 2010s.30343.2132600.82185736153.4532900.831838
C2H6 30062.8933200.90184035843.1033510.911825
C2H4 30532.3834860.88187536352.5935210.891855
RP-1 (kerosene)Kerolox. Common.29412.5834031.03179935102.7734281.031783
N2H4 30650.9231321.07189234600.9831461.071878
B5H9 31242.1238340.92189537582.1638630.921894
B2H6 33511.9634890.74204140162.0635630.752039
CH4:H2 92.6:7.431263.3632450.71192037193.6332870.721897
GOX GH2 Gaseous form39973.292576255044853.9228622519
F2 H2 40367.9436890.46255646979.7439850.522530
H2:Li 65.2:34.042560.9618300.192680
H2:Li 60.7:39.350501.0819740.212656
CH4 34144.5339181.03206840754.7439331.042064
C2H6 33353.6839141.09201939873.7839231.102014
MMH 34132.3940741.24206340712.4740911.241987
N2H4 35802.3244611.31221942152.3744681.312122
NH3 35313.3243371.12219441433.3543411.122193
B5H9 35025.1450501.23214741915.5850831.252140
OF2 H2 40145.9233110.39254246797.3735870.442499
CH4 34854.9441571.06216041315.5842071.092139
C2H6 35113.8745391.13217641373.8645381.132176
RP-1 34243.8744361.28213240213.8544321.282130
MMH 34272.2840751.24211940672.5841331.262106
N2H4 33811.5137691.26208740081.6538141.272081
MMH:N2H4:H2O 50.5:29.8:19.732861.7537261.24202539081.9237691.252018
B2H6 36533.9544791.01224443673.9844861.022167
B5H9 35394.1648251.20216342394.3048441.212161
F2:O2 30:70 H2 38714.8029540.32245345205.7031950.362417
RP-1 31033.0136651.09190836973.3036921.101889
F2:O2 70:30 RP-1 33773.8443611.20210639553.8443611.202104
F2:O2 87.8:12.2 MMH 35252.8244541.24219141482.8344531.232186
OxidizerFuelCommentVerTcdC*VerTcdC*
N2F4 CH4 31276.4437051.15191736926.5137071.151915
C2H4 30353.6737411.13184436123.7137431.141843
MMH 31633.3538191.32192837303.3938231.321926
N2H4 32833.2242141.38205938273.2542161.382058
NH3 32044.5840621.22202037234.5840621.222021
B5H9 32597.7647911.34199738988.3148031.351992
ClF5 MMH 29622.8235771.40183734882.8335791.401837
N2H4 30692.6638941.47193535802.7139051.471934
MMH:N2H4 86:1429712.7835751.41184434982.8135791.411844
MMH:N2H4:N2H5NO3 55:26:1929892.4637171.46186435002.4937221.461863
ClF3 MMH:N2H4:N2H5NO355:26:19Hypergolic27892.9734071.42173932743.0134131.421739
N2H4 Hypergolic28852.8136501.49182433562.8936661.501822
N2O4 MMH Hypergolic, common28272.1731221.19174533472.3731251.201724
MMH:Be 76.6:29.431060.9931931.17185837201.1034511.241849
MMH:Al 63:2728910.8532941.271785
MMH:Al 58:4234600.8734501.311771
N2H4 Hypergolic, common28621.3629921.21178133691.4229931.221770
N2H4:UDMH 50:50Hypergolic, common28311.9830951.12174733492.1530961.201731
N2H4:Be 80:2032090.5130381.201918
N2H4:Be 76.6:23.438490.6032301.221913
B5H9 29273.1836781.11178235133.2637061.111781
NO:N2O4 25:75 MMH 28392.2831531.17175333602.5031581.181732
N2H4:Be 76.6:23.428721.4330231.19178733811.5130261.201775
IRFNA IIIa UDMH:DETA 60:40Hypergolic26383.2628481.30162731233.4128391.311617
MMH Hypergolic26902.5928491.27166531782.7128411.281655
UDMH Hypergolic26683.1328741.26164831573.3128641.271634
IRFNA IV HDA UDMH:DETA 60:40Hypergolic26893.0629031.32165631873.2529511.331641
MMH Hypergolic27422.4329531.29169632422.5829471.311680
UDMH Hypergolic27192.9529831.28167632203.1229771.291662
H2O2 MMH 27903.4627201.24172633013.6927071.241714
N2H4 28102.0526511.24175133082.1226451.251744
N2H4:Be 74.5:25.532890.4829151.21194339540.5730981.241940
B5H9 30162.2026671.02182836422.0925971.011817
OxidizerFuelCommentVerTcdC*VerTcdC*

Definitions of some of the mixtures:

IRFNA IIIa
83.4% HNO3, 14% NO2, 2% H2O, 0.6% HF
IRFNA IV HDA
54.3% HNO3, 44% NO2, 1% H2O, 0.7% HF
RP-1
See MIL-P-25576C, basically kerosene (approximately C
10
H
18
)
MMH monomethylhydrazine
CH
3
NHNH
2

Has not all data for CO/O2, purposed for NASA for Martian-based rockets, only a specific impulse about 250 s.

r
Mixture ratio: mass oxidizer / mass fuel
Ve
Average exhaust velocity, m/s. The same measure as specific impulse in different units, numerically equal to specific impulse in N·s/kg.
C*
Characteristic velocity, m/s. Equal to chamber pressure multiplied by throat area, divided by mass flow rate. Used to check experimental rocket's combustion efficiency.
Tc
Chamber temperature, °C
d
Bulk density of fuel and oxidizer, g/cm3

Monopropellants

PropellantCommentOptimal expansion from
68.05 atm to 1 atm[ citation needed ]
Expansion from
68.05 atm to vacuum (0 atm)
(Areanozzle = 40:1)[ citation needed ]
VeTcdC*VeTcdC*
Ammonium dinitramide (LMP-103S) [32] [33] PRISMA mission (2010–2015)
5 S/Cs launched 2016 [34]
16081.2416081.24
Hydrazine [33] Common8831.018831.01
Hydrogen peroxide Common161012701.451040186012701.451040
Hydroxylammonium nitrate (AF-M315E) [33] 18931.4618931.46
Nitromethane
PropellantCommentVeTcdC*VeTcdC*

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Nitrous oxide fuel blend propellants are a class of liquid rocket propellants that were intended in the early 2010s to be able to replace hydrazine as the standard storable rocket propellent in some applications.

<span class="mw-page-title-main">Rocket propellant</span> Chemical or mixture used in a rocket engine

Rocket propellant is used as reaction mass ejected from a rocket engine to produce thrust. The energy required can either come from the propellants themselves, as with a chemical rocket, or from an external source, as with ion engines.

<span class="mw-page-title-main">SpaceX rocket engines</span> Rocket engines developed by SpaceX

Since the founding of SpaceX in 2002, the company has developed four families of rocket engines — Merlin, Kestrel, Draco and SuperDraco — and since 2016 developed the Raptor methane rocket engine and after 2020, a line of methalox thrusters.

<span class="mw-page-title-main">Liquid apogee engine</span>

A liquid apogee engine (LAE), or apogee engine, refers to a type of chemical rocket engine typically used as the main engine in a spacecraft.

<span class="mw-page-title-main">SpaceX Raptor</span> SpaceX family of liquid-fuel rocket engines

Raptor is a family of rocket engines developed and manufactured by SpaceX. It is the third rocket engine in history designed with a full-flow staged combustion (FFSC) fuel cycle, and the first such engine to power a vehicle in flight. The engine is powered by cryogenic liquid methane and liquid oxygen, a mixture known as methalox.

References

  1. Larson, W.J.; Wertz, J.R. (1992). Space Mission Analysis and Design. Boston: Kluver Academic Publishers.
  2. Sutton, G. P. (2003). "History of liquid propellant rocket engines in the united states". Journal of Propulsion and Power. 19 (6): 978–1007. doi:10.2514/2.6942.
  3. Tsiolkovsky, Konstantin E. (1903), "The Exploration of Cosmic Space by Means of Reaction Devices (Исследование мировых пространств реактивными приборами)", The Science Review (in Russian) (5), archived from the original on 19 October 2008, retrieved 22 September 2008
  4. Zumerchik, John, ed. (2001). Macmillan encyclopedia of energy . New York: Macmillan Reference USA. ISBN   0028650212. OCLC   44774933.
  5. MJ Neufeld. "The Rocketry and Spaceflight Fad in Germany, 1923-1933" (PDF).
  6. Valier, Max. Raketenfahrt (in German). pp. 209–232. doi:10.1515/9783486761955-006. ISBN   978-3-486-76195-5.
  7. 1 2 Clark, John Drury (23 May 2018). Ignition!: An Informal History of Liquid Rocket Propellants. Rutgers University Press. p. 302. ISBN   978-0-8135-9918-2.
  8. British site on the HWK firm
  9. Walter site-page on the Starthilfe system
  10. Wlater site-page on the Henschel air-sea glide bomb
  11. List of 109-509 series Walter rocket motors
  12. Braun, Wernher von (Estate of); Ordway III; Frederick I (1985) [1975]. Space Travel: A History. & David Dooling, Jr. New York: Harper & Row. pp. 83, 101. ISBN   0-06-181898-4.
  13. Ogden, J.M. (1999). "Prospects for building a hydrogen energy infrastructure". Annual Review of Energy and the Environment . 24: 227–279. doi:10.1146/annurev.energy.24.1.227.
  14. Hydrogen production: Natural gas reforming (Report). U.S. Department of Energy . Retrieved 6 April 2017.
  15. Rostrup-Nielsen, Jens R.; Rostrup-Nielsen, Thomas (23 March 2007). Large-scale Hydrogen Production (PDF) (Report). Haldor Topsøe. p. 3. Archived from the original (PDF) on 8 February 2016. Retrieved 16 July 2023. The total hydrogen market in 1998 was 390×109 Nm³/y + 110×109 Nm³/y co-production.
  16. Rhodes, Richard (1995). Dark Sun: The making of the hydrogen bomb. New York, NY: Simon & Schuster. pp. 483–504. ISBN   978-0-684-82414-7.
  17. Sutton, E.P.; Biblarz, O. (2010). Rocket Propulsion Elements (8th ed.). New York: Wiley. ISBN   9780470080245 via Internet Archive.
  18. Zurawski, Robert (June 1986). "Current Evaluation of the Tripropellant Concept" (PDF).
  19. "Intuitive Machines: How this Houston startup is making space history". Fast Company.
  20. "SpaceX propulsion chief elevates crowd in Santa Barbara". Pacific Business Times. 2014-02-19. Retrieved 2014-02-22.
  21. Belluscio, Alejandro G. (2014-03-07). "SpaceX advances drive for Mars rocket via Raptor power". NASAspaceflight.com. Retrieved 2014-03-07.
  22. Beil, Adrian (12 July 2023). "LandSpace claims win in the methane race to orbit via second ZhuQue-2 launch". NASASpaceFlight . Retrieved 16 July 2023.
  23. "China beats rivals to successfully launch first methane-liquid rocket". Reuters. 12 July 2023.
  24. I. Morales Volosín, Juan (12 July 2023). "Second Flight | ZhuQue-2". Everyday Astronaut.
  25. Bell, Adrian (12 July 2023). "LandSpace claims win in the methane race to orbit via second ZhuQue-2 launch". NASASpaceFlight.com . Retrieved 12 July 2023.
  26. Josh Dinner (2024-01-08). "ULA's Vulcan rocket launches private US moon lander, 1st since Apollo, and human remains in debut flight". Space.com. Retrieved 2024-01-08.
  27. "Starship's Third Flight Test". SpaceX. Retrieved 2024-05-07.
  28. Todd, David (2012-11-20). "Musk goes for methane-burning reusable rockets as step to colonise Mars". FlightGlobal/Blogs Hyperbola. Archived from the original on 2012-11-28. Retrieved 2012-11-22. "We are going to do methane." Musk announced as he described his future plans for reusable launch vehicles including those designed to take astronauts to Mars within 15 years.
  29. "Firefly α". Firefly Space Systems. Archived from the original on 6 October 2014. Retrieved 5 October 2014.
  30. Themis, Prometheus complete first hot-fire tests in France
  31. Huzel, D. K.; Huang, D. H. (1971), NASA SP-125, "Modern Engineering for Design of Liquid-Propellant Rocket Engines", (2nd ed.), NASA
  32. Anflo, K.; Moore, S.; King, P. Expanding the ADN-based Monopropellant Thruster Family. 23rd Annual AIAA/USU Conference on Small Satellites. SSC09-II-4.
  33. 1 2 3 Shchetkovskiy, Anatoliy; McKechnie, Tim; Mustaikis, Steven (13 August 2012). Advanced Monopropellants Combustion Chambers and Monolithic Catalyst for Small Satellite Propulsion (PDF). 15th Annual Space and Missile Defense Conference. Huntsville, AL. Retrieved 14 December 2017.
  34. Dingertz, Wilhelm (10 October 2017). HPGP® - High Performance Green Propulsion (PDF). ECAPS: Polish - Swedish Space Industry Meeting. Retrieved 14 December 2017.