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YF-75
The YF-75 is a liquid cryogenic rocket engine burning liquid hydrogen and liquid oxygen in a gas generator cycle. It is China's second generation of cryogenic propellant engine, after the YF-73, which it replaced. It is used in a dual engine mount in the H-18 third stage of the Long March 3A, Long March 3B and Long March 3C launch vehicles. Within the mount, each engine can gimbal individually to enable thrust vectoring control. The engine also heats hydrogen and helium to pressurize the stage tanks and can control the mixture ratio to optimize propellant consumption. Development Given the upward trend on geosynchronous communication satellite's mass and size, a program to develop an engine more powerful than the YF-73 was started by 1982. The proper development of the engine started in 1986 and leveraged the experience of the YF-73. It flew for the first time in 1994. By September 2013, it had accumulated 12 start up and 3,000 seconds of firing time without malfunction. By 2006 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
YF-75D
The YF-75D is a liquid-fuel rocket, liquid cryogenic rocket engine, cryogenic rocket engine burning liquid hydrogen and liquid oxygen in a closed Expander cycle (rocket), expander cycle. It is China's third generation of upper stage cryogenic fuel, cryogenic propellant engine, after the YF-73 and the YF-75. It is used in a dual engine mount in the H5-2 second stage of the Long March 5 launch vehicles. Within the mount, each engine can Gimbaled thrust, gimbal individually to enable thrust vectoring control. As its predecessor, the YF-75 it can adjust its O/F ratio, mixture ratio to optimize propellant consumption. But as an additional improvement, it can do multiple restarts, against the single one of its predecessor. The combustion chamber required a redesign to keep the power balance. Since the expander cycle uses the heat extracted from the cooling circuits to drive the turbines, the chamber had to be lengthened and the cooling passages redesigned. The engine uses a redesigned h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Long March 5
Long March 5 (LM-5; zh, s=长征五号 , p=Chángzhēng wǔ hào), or Changzheng 5 (CZ-5), and also by its nickname "''Pang-Wu''" (胖五, "''Fat-Five''"), is a Chinese heavy-lift launch vehicle developed by the China Academy of Launch Vehicle Technology (CALT). It is the first Chinese launch vehicle designed to use exclusively non-hypergolic liquid propellants. It is the fifth iteration of the Long March rocket family. There are currently two CZ-5 variants: CZ-5 and CZ-5B. The maximum payload capacities are approximately to low Earth orbit (for CZ-5B) and approximately to geostationary transfer orbit (for CZ-5). As of 2021, a 3-core human-rated variant, referred to as CZ-5G, designed for manned moon mission, is under development; this variant will be capable of launching a crewed spacecraft into lunar orbit. The Long March 5 roughly matches the capabilities of American NSSL heavy-lift launch vehicles such as the Delta IV Heavy. It is currently the most powerful member of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryogenic Rocket Engine
A cryogenic rocket engine is a rocket engine that uses a cryogenic fuel and oxidizer; that is, both its fuel and oxidizer are gases which have been liquefied and are stored at very low temperatures. These highly efficient engines were first flown on the US Atlas-Centaur and were one of the main factors of NASA's success in reaching the Moon by the Saturn V rocket. Rocket engines burning cryogenic propellants remain in use today on high performance upper stages and boosters. Upper stages are numerous. Boosters include ESA's Ariane 5, JAXA's H-II, and the United States Delta IV and Space Launch System. The United States, Russia, Japan, India, France and China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ... are the only countries that have operational cryogenic rocket engines ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
YF-73
The YF-73 was China's first successful cryogenic liquid hydrogen fuel and liquid oxygen oxidizer gimballed engine. It was used on the Long March 3 H8 third stage, running on the simple gas generator cycle and with a thrust of . It had four hinge mounted nozzles that gimbaled each on one axis to supply thrust vector control and was restart capable. It used cavitating flow venturis to regulate propellant flows. The gas generator also incorporated dual heat exchangers that heated hydrogen gas, and supplied helium from separate systems to pressurize the hydrogen and oxygen tanks. The engine was relatively underpowered for its task and the start up and restart procedures were unreliable. Thus, it was quickly replaced by the YF-75. History In October 1970 the Beijing Aerospace Propulsion Institute was tasked with developing a prototype rocket engine burning liquid hydrogen and liquid oxygen. They settled on a pump-fed gas generator design. The prototype was successfully fire tested f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Long March 3B
The Long March 3B (, ''Chang Zheng 3B''), also known as the CZ-3B and LM-3B, is a Chinese orbital launch vehicle. Introduced in 1996, it is launched from Launch Area 2 and 3 at the Xichang Satellite Launch Center in Sichuan. A three-stage rocket with four strap-on liquid rocket boosters, it is currently the second most powerful member of the Long March (rocket family), Long March rocket family after the Long March 5 and the heaviest of the Long March 3 rocket family, and is mainly used to place communications satellites into geosynchronous orbits. An enhanced version, the Long March 3B/E or G2, was introduced in 2007 to increase the rocket's geostationary transfer orbit (GTO) cargo capacity and lift heavier geosynchronous orbit (GEO) communications satellites. The Long March 3B also served as the basis for the medium-capacity Long March 3C, which was first launched in 2008. , the Long March 3B, 3B/E and 3B/G5 have conducted 82 successful launches, plus 2 failures and 2 partial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Long March 3A
The Long March 3A (), also known as the Chang Zheng 3A, CZ-3A and LM-3A, is a Chinese orbital carrier rocket design. It is a 3-stage rocket, and is usually used to place communications satellites and Beidou navigation satellites into geosynchronous transfer orbits. It has formed the basis of the Long March 3B, which is a heavier version with four liquid booster rockets. Launches Long March 3A rockets have been launched from Launch Areas 2 and 3 at the Xichang Satellite Launch Center. List of launches Technical data LM-3A is a 3-stage launch vehicle developed on the basis of LM-3 and LM-2C. Its third stage is powered by cryogenic propellants: liquid hydrogen and liquid oxygen Liquid oxygen—abbreviated LOx, LOX or Lox in the aerospace, submarine and gas industries—is the liquid form of molecular oxygen. It was used as the oxidizer in the first liquid-fueled rocket invented in 1926 by Robert H. Goddard, an applica .... It is dedicated for launching spacecraft into ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Long March 3C
The Long March 3C (), also known as the Changzheng 3C, CZ-3C and LM-3C, is a Chinese orbital launch vehicle. It is launched from Launch Complex 2 and 3 at the Xichang Satellite Launch Center (XSLC). A three-stage rocket with two strapon liquid rocket boosters, it is a member of the Long March 3 rocket family, and was derived from the Long March 3B. It was designed to fill a gap in payload capacities between the Long March 3A and 3B. Launch Statistics Launches It made its maiden flight on 25 April 2008, at 15:35 UTC. The payload for the first launch was the Tianlian I-01 data relay communications satellite. The second carried the Compass-G2 navigation satellite and was conducted on 14 April 2009. The third launch was made on 16 January 2010, with the Compass-G1 satellite. The fourth carrying the Compass-G3 navigation satellite was launched on 2 June 2010. On 1 October 2010, it successfully launched China's second lunar probe, Chang'e 2. An enhanced version, named Lon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and borders fourteen countries by land, the most of any country in the world, tied with Russia. Covering an area of approximately , it is the world's third largest country by total land area. The country consists of 22 provinces, five autonomous regions, four municipalities, and two Special Administrative Regions (Hong Kong and Macau). The national capital is Beijing, and the most populous city and financial center is Shanghai. Modern Chinese trace their origins to a cradle of civilization in the fertile basin of the Yellow River in the North China Plain. The semi-legendary Xia dynasty in the 21st century BCE and the well-attested Shang and Zhou dynasties developed a bureaucratic political system to serve hereditary monarchies, or dyna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Regenerative Cooling (rocket)
Regenerative cooling, in the context of rocket engine design, is a configuration in which some or all of the propellant is passed through tubes, channels, or in a jacket around the combustion chamber or nozzle to cool the engine. This is effective because the propellants are often cryogenic. The heated propellant is then fed into a special gas-generator or injected directly into the main combustion chamber. History In 1857 Carl Wilhelm Siemens introduced the concept of regenerative cooling. On 10 May 1898, James Dewar used regenerative cooling to become the first to statically liquefy hydrogen. The concept of regenerative cooling was also mentioned in 1903 in an article by Konstantin Tsiolkovsky. Robert Goddard built the first regeneratively cooled engine in 1923, but rejected the scheme as too complex. A regeneratively cooled engine was built by the Italian researcher, Gaetano Arturo Crocco in 1930. The first Soviet engines to employ the technique were Fridrikh Tsander's OR-2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rocket Engine
A rocket engine uses stored rocket propellants as the reaction mass for forming a high-speed propulsive jet of fluid, usually high-temperature gas. Rocket engines are reaction engines, producing thrust by ejecting mass rearward, in accordance with Newton's third law. Most rocket engines use the combustion of reactive chemicals to supply the necessary energy, but non-combusting forms such as cold gas thrusters and nuclear thermal rockets also exist. Vehicles propelled by rocket engines are commonly called rockets. Rocket vehicles carry their own oxidiser, unlike most combustion engines, so rocket engines can be used in a vacuum to propel spacecraft and ballistic missiles. Compared to other types of jet engine, rocket engines are the lightest and have the highest thrust, but are the least propellant-efficient (they have the lowest specific impulse). The ideal exhaust is hydrogen, the lightest of all elements, but chemical rockets produce a mix of heavier species, reducing the e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Revolutions Per Minute
Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or with the notation min−1) is a unit of rotational speed or rotational frequency for rotating machines. Standards ISO 80000-3:2019 defines a unit of rotation as the dimensionless unit equal to 1, which it refers to as a revolution, but does not define the revolution as a unit. It defines a unit of rotational frequency equal to s−1. The superseded standard ISO 80000-3:2006 did however state with reference to the unit name 'one', symbol '1', that "The special name revolution, symbol r, for this unit is widely used in specifications on rotating machines." The International System of Units (SI) does not recognize rpm as a unit, and defines the unit of frequency, Hz, as equal to s−1. :\begin 1~&\text &&=& 60~&\text \\ \frac~&\text &&=& 1~&\text \end A corresponding but distinct quantity for describing rotation is angular velocity, for which the SI unit is the ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrotechnic Initiator
In pyrotechnics, a pyrotechnic initiator (also initiator or igniter) is a device containing a pyrotechnic composition used primarily to ignite other, more difficult-to-ignite materials, such as thermites, gas generators, and solid-fuel rockets. The name is often used also for the compositions themselves. Pyrotechnic initiators are often controlled electrically (called electro-pyrotechnic initiators), e.g. using a heated bridgewire or a ''bridge resistor''. They are somewhat similar to blasting caps or other detonators, but they differ in that there is no intention to produce a shock wave. An example of such pyrotechnic initiator is an electric match. Composition The energetic material used, often called pyrogen, is usually a pyrotechnic composition made of a fuel and oxidizer, where the fuel produces a significant amount of hot particles that cause/promote the ignition of the desired material. Initiator compositions are similar to flash powders, but they differ in burning speed, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
