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Pressure-fed Engine
The pressure-fed engine is a class of rocket engine designs. A separate gas supply, usually helium, pressurizes the propellant tanks to force fuel and oxidizer to the combustion chamber. To maintain adequate flow, the tank pressures must exceed the combustion chamber pressure. Pressure fed engines have simple plumbing and have no need for complex and occasionally unreliable turbopumps. A typical startup procedure begins with opening a valve, often a one-shot pyrotechnic device, to allow the pressurizing gas to flow through check valves into the propellant tanks. Then the propellant valves in the engine itself are opened. If the fuel and oxidizer are hypergolic, they burn on contact; non-hypergolic fuels require an igniter. Multiple burns can be conducted by merely opening and closing the propellant valves as needed, if the pressurization system also has activating valves. They can be operated electrically, or by gas pressure controlled by smaller electrically operated valves. Care ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pressure Fed Rocket Cycle
Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and even by industry. Further, both spellings are often used ''within'' a particular industry or country. Industries in British English-speaking countries typically use the "gauge" spelling. is the pressure relative to the ambient pressure. Various units are used to express pressure. Some of these derive from a unit of force divided by a unit of area; the SI unit of pressure, the pascal (Pa), for example, is one newton per square metre (N/m2); similarly, the pound-force per square inch (psi) is the traditional unit of pressure in the imperial and U.S. customary systems. Pressure may also be expressed in terms of standard atmospheric pressure; the atmosphere (atm) is equal to this pressure, and the torr is defined as of this. Manometri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SpaceX Dragon 2
Dragon 2 is a class of partially reusable spacecraft developed and manufactured by American aerospace manufacturer SpaceX, primarily for flights to the International Space Station (ISS). SpaceX has also launched Private spaceflight, private missions such as Inspiration4 and Axiom Mission 1. There are two variants: Crew Dragon, a spacecraft capable of ferrying four crew, and Cargo Dragon, an updated replacement for the original SpaceX Dragon, Dragon 1. The spacecraft consists of a reuseable space capsule and an expendable trunk module. The spacecraft launches atop a Falcon 9 Block 5 rocket and the capsule returns to Earth via splashdown. Cargo Dragon space logistics, supplies cargo to the ISS under a Commercial Resupply Services#Commercial Resupply Services phase 2, Commercial Resupply Services-2 contract with NASA. The SpaceX CRS-21, first flight of Dragon 2 in a cargo configuration launched in December 2020. It shares this duty with Northrop Grumman Innovation Systems' Cygnus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OTRAG (rocket)
The OTRAG rocket was a modular satellite-delivery rocket developed by the OTRAG company in the 1970s and 80s. The OTRAG rocket was to become a rocket built up from several mass-produced units, intended to carry satellites with a weight of 1-10 tons or more into orbit. Mass production meant that the vehicle was projected to have been 10x cheaper than conventional vehicles of similar capability. Design Various OTRAG rockets could be built up from the company's CRPUs (Common Rocket Propulsion Unit). A sounding rocket would bundle four or more CRPUs in parallel, topped with the payload. An orbital launcher would use dozens to hundreds of CRPUs, depending on payload mass. The launcher would then stage by dropping outer CRPUs, leaving the interior ones to continue with payload. A CRPU was essentially a steel tube, 27 cm in diameter and 16 meters long, joined from a few shorter tubes. The CRPU was divided into three sections by aluminium bulkheads, with additional stiffening ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solid-fuel Rocket
A solid-propellant rocket or solid rocket is a rocket with a rocket engine that uses solid propellants ( fuel/oxidizer). The earliest rockets were solid-fuel rockets powered by gunpowder; they were used in warfare by the Arabs, Chinese, Persians, Mongols, and Indians as early as the 13th century. All rockets used some form of solid or powdered propellant up until the 20th century, when liquid-propellant rockets offered more efficient and controllable alternatives. Solid rockets are still used today in military armaments worldwide, model rockets, solid rocket boosters and on larger applications for their simplicity and reliability. Since solid-fuel rockets can remain in storage for an extended period without much propellant degradation and because they almost always launch reliably, they have been frequently used in military applications such as missiles. The lower performance of solid propellants (as compared to liquids) does not favor their use as primary propulsion in mode ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Launch Vehicle
A launch vehicle or carrier rocket is a rocket designed to carry a payload (spacecraft or satellites) from the Earth's surface to outer space. Most launch vehicles operate from a launch pad, launch pads, supported by a missile launch control center, launch control center and systems such as vehicle assembly and fueling. Launch vehicles are engineered with advanced aerodynamics and technologies, which contribute to large operating costs. An orbital spaceflight, orbital launch vehicle must lift its payload at least to the boundary of space, approximately and accelerate it to a horizontal velocity of at least . Suborbital spaceflight, Suborbital vehicles launch their payloads to lower velocity or are launched at elevation angles greater than horizontal. Practical orbital launch vehicles are multistage rockets which use chemical propellants such as Solid-propellant rocket, solid fuel, liquid hydrogen, kerosene, liquid oxygen, or Hypergolic propellants. Launch vehicles are cla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Big Dumb Booster
Big Dumb Booster (BDB) is a general class of launch vehicle based on the premise that it is cheaper to operate large rockets of simple design than it is to operate smaller, more complex ones regardless of the lower payload efficiency.Schnitt, Arthur (1998''Minimum Cost Design for Space Operations''./ref> As referred to by the Office of Technology Assessment: Even though the large minimum-cost design (MCD) booster is less efficient for all around operation, its total cost of operation is cheaper because it is easier to build, operate and maintain, with the benefit of high reliability because of reduced parts counts. History Concept work was led by proponents at Aerospace Corporation, TRW, and Aerojet General, beginning in the late 1950s. The typical approach included maraging steel ( HY-140) for structure, pressure-fed engines using / UDMH, later LOX /RP-1, with pintle injectors scaled up from TRW's Lunar Module Descent Engine (LMDE). The Sea Dragon was an extremely lar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Truax
Captain Robert C. Truax (USN) (September 3, 1917 – September 17, 2010) was an American rocket engineer in the United States Navy, and companies such as Aerojet and Truax Engineering, which he founded. Truax was a proponent of low-cost rocket engine and vehicle designs. Life As a teenager, Truax was inspired by Robert Goddard articles in ''Popular Mechanics'' magazine to build his own rockets while residing in Alameda, California. From 1936 to 1939, midshipman Truax tested liquid-fuel rocket motors and published a February 1939 report in Astronautics. In 1938, he showed a thrust chamber that he had constructed to the British Interplanetary Society and wrote technical reports published by the American Rocket Society. Following two years' sea duty, first on and then a destroyer, then-Lieutenant Commander Truax worked at the Engineering Experiment Station at Annapolis in the Bureau of Aeronautics Ship Installations Division under Commander C. A. Bolster. Truax headed the N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Dragon (rocket)
The Sea Dragon was a 1962 conceptualized design study for a two-stage sea-launched orbital super heavy-lift launch vehicle. The project was led by Robert Truax while working at Aerojet, one of a number of designs he created that were to be launched by floating the rocket in the ocean. Although there was some interest at both NASA and Todd Shipyards, the project was not implemented. With dimensions of long and in diameter, Sea Dragon would have been the largest rocket ever built. , among rockets that have been fully conceived but not built, it is by far the largest ever and, in terms of payload into low Earth orbit (LEO), equaled only by the Interplanetary Transport System concept (the predecessor to SpaceX Starship) in the latter's expendable configuration with both designed for 550 tonnes. Design Truax's basic idea was to produce a low-cost heavy launcher, a concept now called "big dumb booster." To lower the cost of operation, the rocket itself was launched from the ocean, r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Falcon 1
Falcon 1 was a small-lift launch vehicle that was operated from 2006 to 2009 by SpaceX, an American aerospace manufacturer. On 28 September 2008, Falcon 1 became the first privately-developed fully liquid-fueled launch vehicle to go into orbit around the Earth. The two-stage-to-orbit rocket used LOX/RP-1 for both stages, the first powered by a single Merlin engine and the second powered by a single Kestrel engine. It was designed by SpaceX from the ground up. The vehicle was launched a total of five times. After three failed launch attempts, Falcon 1 achieved orbit on its fourth attempt in September 2008 with a mass simulator as a payload. On 14 July 2009, Falcon 1 made its second and final flight, successfully delivering the Malaysian RazakSAT satellite to orbit on SpaceX's first commercial launch (fifth launch overall). Following this flight, the Falcon 1 was retired and succeeded by Falcon 9. SpaceX had announced an enhanced variant, the Falcon 1e, but development was st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kestrel (rocket Engine)
The SpaceX Kestrel was an LOX/RP-1 pressure-fed rocket engine. The Kestrel engine was developed in the 2000s by SpaceX for upper stage use on the Falcon 1 rocket. Kestrel is no longer being manufactured; the last flight of Falcon 1 was in 2009. Kestrel was built around the same pintle architecture as the SpaceX Merlin engine but does not have a turbopump and is fed only by tank pressure. Kestrel was ablatively cooled in the chamber and throat and radiatively cooled in the nozzle, which was fabricated from a high strength niobium alloy. As a metal, niobium is highly resistant to cracking compared to carbon-carbon. According to SpaceX, an impact from orbital debris or during stage separation might dent the metal but have no meaningful effect on engine performance. Helium pressurant efficiency is substantially increased via a titanium heat exchanger on the ablative/niobium boundary. Thrust vector control is provided by electro-mechanical actuators on the engine dome for pitc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delta II
Delta II was an expendable launch system, originally designed and built by McDonnell Douglas. Delta II was part of the Delta rocket family and entered service in 1989. Delta II vehicles included the Delta 6000, and the two later Delta 7000 variants ("Light" and "Heavy"). The rocket flew its final mission ICESat-2 on 15 September 2018, earning the launch vehicle a streak of 100 successful missions in a row, with the last failure being GPS IIR-1 in 1997. History In the early 1980s, all United States expendable launch vehicles were planned to be phased out in favor of the Space Shuttle, which would be responsible for all government and commercial launches. Production of Delta, Atlas-Centaur, and Titan 34D had ended. The ''Challenger'' disaster of 1986 and the subsequent halt of Shuttle operations changed this policy, and President Ronald Reagan announced in December 1986 that the Space Shuttle would no longer launch commercial payloads, and NASA would seek to purchase launches ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
