|
Pogo Oscillation
Pogo oscillation is a self-excited vibration in liquid-propellant rocket engines caused by Rocket engine#Combustion instabilities, combustion instability. The unstable combustion results in variations of engine thrust, causing variations of acceleration on the vehicle's flexible structure, which in turn cause variations in propellant pressure and flow rate, closing the self-excitation cycle. The name is a metaphor comparing the Flight control surfaces#Longitudinal axis, longitudinal vibration to the bouncing of a pogo stick. Pogo oscillation places stress on the frame of the vehicle, which in severe cases can be dangerous. Origin NASA Associate Administrator for Manned Space Flight George Mueller (NASA), George Mueller explained Apollo 6's pogo oscillation to a congressional hearing: In general, pogo oscillation occurs when a surge in combustion chamber pressure increases back pressure against the fuel coming into the engine. This reduces fuel flow and thus chamber pressure. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vibration
Vibration () is a mechanical phenomenon whereby oscillations occur about an equilibrium point. Vibration may be deterministic if the oscillations can be characterised precisely (e.g. the periodic motion of a pendulum), or random if the oscillations can only be analysed statistically (e.g. the movement of a tire on a gravel road). Vibration can be desirable: for example, the motion of a tuning fork, the reed in a woodwind instrument or harmonica, a mobile phone, or the cone of a loudspeaker. In many cases, however, vibration is undesirable, wasting energy and creating unwanted sound. For example, the vibrational motions of engines, electric motor An electric motor is a machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a electromagnetic coil, wire winding to gene ...s, or any Machine, mechanical device in operation are typically unwanted. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Princeton University
Princeton University is a private university, private Ivy League research university in Princeton, New Jersey, United States. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial Colleges, fourth-oldest institution of higher education in the United States and one of the nine colonial colleges chartered before the American Revolution. The institution moved to Newark, New Jersey, Newark in 1747 and then to its Mercer County, New Jersey, Mercer County campus in Princeton nine years later. It officially became a university in 1896 and was subsequently renamed Princeton University. The university is governed by the Trustees of Princeton University and has an endowment of $37.7 billion, the largest List of colleges and universities in the United States by endowment, endowment per student in the United States. Princeton provides undergraduate education, undergraduate and graduate education, graduate instruction in the hu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RS-25
The RS-25, also known as the Space Shuttle Main Engine (SSME), is a liquid-fuel cryogenic rocket engine that was used on NASA's Space Shuttle and is used on the Space Launch System. Designed and manufactured in the United States by Rocketdyne (later Pratt & Whitney Rocketdyne and Aerojet Rocketdyne), the RS-25 burns cryogenic (very low temperature) liquid hydrogen and liquid oxygen propellants, with each engine producing thrust at liftoff. Although RS-25 heritage traces back to the 1960s, its concerted development began in the 1970s with the first flight, STS-1, on April 12, 1981. The RS-25 has undergone upgrades over its operational history to improve the engine's thrust, reliability, safety, and maintenance load. The engine produces a specific impulse (''I''sp) of 452 seconds (4.43 kN-sec/kg) in vacuum, or 366 seconds (3.59 kN-sec/kg) at sea level, has a mass of approximately , and is capable of throttling between 67% and 109% of its rated power level in one- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boris Chertok
Boris Yevseyevich Chertok (; – 14 December 2011) was a Russian engineer in the former Soviet space program, mainly working in control systems, and later found employment in Roscosmos. Major responsibility under his guidance was primarily based on computerized control system of the Russian missiles and rocketry system, and authored the four-volume book ''Rockets and People''– the definitive source of information about the history of the Soviet space program. From 1974, he was the deputy chief designer of the Korolev design bureau, the space aircraft designer bureau which he started working for in 1946. He retired in 1992. Personal life Born in Łódź (modern Poland), his family moved to Moscow when he was aged 3. Starting from 1930, he worked as an electrician in a metropolitan suburb. Since 1934, he was already designing military aircraft in Bolkhovitinov design bureau. In 1946, he entered the rocket-pioneering NII-88 as a head of control systems department, working al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luna E-1 No
Luna commonly refers to: * Earth's Moon, named "Luna" in Latin, Spanish and other languages * Luna (goddess), the ancient Roman personification of the Moon * Luna (name), including a list of people and characters with this given name and surname * Luna marble, the ancient Roman term for Carrara marble Luna may also refer to: Places Philippines * Luna, Apayao * Luna, Isabela * Luna, La Union * Luna, San Jose Romania * Luna, Negrești-Oaș town, Satu Mare County * Luna, Cluj * Luna de Jos, Dăbâca Commune, Cluj County * Luna de Sus, Florești, Cluj * Luna River United States * Luna, Arkansas * Luna, Missouri * Luna, Minnesota * Luna, New Mexico * Luna County, New Mexico * Luna Island, in Niagara Falls, New York * Luna Lake (Arizona), a natural body of water * Luna Pier, Michigan, a city Other places * Luna (Etruria), a city in ancient Etruria (now Italy) destroyed by the Arabs in 1016 * , tributary of Órbigo * Luna, Aragon, Spain * Luna, Rajasthan, India * Luna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
N1 (rocket)
The N1 (from , "Carrier Rocket"; Cyrillic: Н1) was a super heavy-lift launch vehicle intended to deliver payloads beyond low Earth orbit. The N1 was the Soviet counterpart to the US Saturn V and was intended to enable crewed travel to the Moon and beyond, with studies beginning as early as 1959. Its first stage, Block A, was the most powerful rocket stage ever flown for over 50 years, with the record standing until Starship's first integrated flight test. However, each of the four attempts to launch an N1 failed in flight, with the second attempt resulting in the vehicle crashing back onto its launch pad shortly after liftoff. Adverse characteristics of the large cluster of thirty engines and its complex fuel and oxidizer feeder systems were not revealed earlier in development because static test firings had not been conducted. The N1-L3 version was designed to compete with the United States Apollo program to land a person on the Moon, using a similar lunar orbit rendezvou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soviet Union
The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet Union, it dissolved in 1991. During its existence, it was the list of countries and dependencies by area, largest country by area, extending across Time in Russia, eleven time zones and sharing Geography of the Soviet Union#Borders and neighbors, borders with twelve countries, and the List of countries and dependencies by population, third-most populous country. An overall successor to the Russian Empire, it was nominally organized as a federal union of Republics of the Soviet Union, national republics, the largest and most populous of which was the Russian SFSR. In practice, Government of the Soviet Union, its government and Economy of the Soviet Union, economy were Soviet-type economic planning, highly centralized. As a one-party state go ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rocketdyne J-2
The J-2, commonly known as Rocketdyne J-2, was a liquid-fuel rocket, liquid-fuel cryogenic rocket engine used on NASA's Saturn IB and Saturn V launch vehicles. Built in the United States by Rocketdyne, the J-2 burned Cryogenic fuel, cryogenic liquid hydrogen (LH2) and liquid oxygen (LOX) propellants, with each engine producing of thrust in vacuum. The engine's preliminary design dates back to recommendations of the 1959 Silverstein Committee. Rocketdyne won approval to develop the J-2 in June 1960 and the first flight, AS-201, occurred on 26 February 1966. The J-2 underwent several minor upgrades over its operational history to improve the engine's performance, with two major upgrade programs, the de Laval nozzle-type J-2S and Aerospike engine, aerospike-type J-2T, which were cancelled after the conclusion of the Apollo program. The engine produced a specific impulse (''I''sp) of in a vacuum (or at sea level) and had a mass of approximately . Five J-2 engines were used on the Sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apollo 13
Apollo 13 (April 1117, 1970) was the seventh crewed mission in the Apollo program, Apollo space program and would have been the third Moon landing. The craft was launched from Kennedy Space Center on April 11, 1970, but the landing was aborted after an oxygen tank in the Apollo command and service module#Service module (SM), service module (SM) exploded two days into the mission, disabling its electrical and life-support system. The crew, supported by backup systems on the Apollo Lunar Module, lunar module (LM), instead looped around the Moon in a circumlunar trajectory and returned safely to Earth on April 17. The mission was commanded by Jim Lovell, with Jack Swigert as Apollo command and service module#Command module (CM), command module (CM) pilot and Fred Haise as Apollo Lunar Module, Lunar Module (LM) pilot. Swigert was a late replacement for Ken Mattingly, who was grounded after exposure to rubella. A routine stir of an oxygen tank ignited damaged wire insulation insid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S-II
The S-II (pronounced "S-two") was the second stage of the Saturn V rocket. It was built by North American Aviation. Using liquid hydrogen (LH2) and liquid oxygen (LOX) it had five J-2 engines in a quincunx pattern. The second stage accelerated the Saturn V through the upper atmosphere with of thrust. History The beginning of the S-II came in December 1959 when a committee recommended the design and construction of a high-thrust, liquid hydrogen fueled engine. The contract for this engine was given to Rocketdyne and it would be later called the J-2. At the same time the S-II stage design began to take shape. Initially it was to have four J-2 engines and be in length and in diameter. In 1961 the Marshall Space Flight Center began the process to find the contractor to build the stage. Out of the 30 aerospace companies invited to a conference where the initial requirements were laid out, only seven submitted proposals a month later. Three of these were eliminated after their p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apollo Abort Modes
Apollo abort modes were procedures by which the nominal launch of an Apollo spacecraft, either the Saturn IB or Saturn V rocket, could be terminated. The abort of the flight allowed for the rescue of the crew if the rocket failed catastrophically. Depending on how far the flight had progressed, different procedure or modes would be used. In the history of the Apollo Program, none of the abort modes were ever used on any of the fifteen crewed Apollo spacecraft flights. Houston's announcements of the current abort mode and the spacecraft commander's acknowledgements were among the few things said on the radio link during the first minutes of flight. If the rocket failed during the first phases of the flight, the Emergency Detection System (EDS) would automatically give the command to abort. The reason is that life-threatening situations can develop too fast for humans to discuss and react to. In the later, less violent phases of the ascent, the EDS was turned off and an abort woul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S-IC
The S-IC (pronounced S-one-C) was the first stage of the American Saturn V rocket. The S-IC stage was manufactured by the Boeing Company. Like the first stages of most rockets, more than 90% of the mass at launch was propellant, in this case RP-1 rocket fuel and liquid oxygen (LOX) oxidizer. It was tall and in diameter. The stage provided of thrust at sea level to get the rocket through the first of ascent. The stage had five F-1 engines in a quincunx arrangement. The center engine was fixed in position, while the four outer engines could be hydraulically gimballed to control the rocket. Manufacturing The Boeing Co. was awarded the contract to manufacture the S-IC on December 15, 1961. By this time the general design of the stage had been decided on by the engineers at the Marshall Space Flight Center (MSFC). The main place of manufacture was the Michoud Assembly Facility, New Orleans. Wind tunnel testing took place in Seattle and the machining of the tools needed to build ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
