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Hypersonic
In aerodynamics, a hypersonic speed is one that exceeds 5 times the speed of sound, often stated as starting at speeds of Mach 5 and above. The precise Mach number at which a craft can be said to be flying at hypersonic speed varies, since individual physical changes in the airflow (like molecular dissociation and ionization) occur at different speeds; these effects collectively become important around Mach 5-10. The hypersonic regime can also be alternatively defined as speeds where specific heat capacity changes with the temperature of the flow as kinetic energy of the moving object is converted into heat. Characteristics of flow While the definition of hypersonic flow can be quite vague and is generally debatable (especially due to the absence of discontinuity between supersonic and hypersonic flows), a hypersonic flow may be characterized by certain physical phenomena that can no longer be analytically discounted as in supersonic flow. The peculiarity in hypersonic flows ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmospheric Reentry
Atmospheric entry is the movement of an object from outer space into and through the gases of an atmosphere of a planet, dwarf planet, or natural satellite. There are two main types of atmospheric entry: ''uncontrolled entry'', such as the entry of astronomical objects, space debris, or bolides; and ''controlled entry'' (or ''reentry'') of a spacecraft capable of being navigated or following a predetermined course. Technologies and procedures allowing the controlled atmospheric ''entry, descent, and landing'' of spacecraft are collectively termed as ''EDL''. Objects entering an atmosphere experience atmospheric drag, which puts mechanical stress on the object, and aerodynamic heating—caused mostly by compression of the air in front of the object, but also by drag. These forces can cause loss of mass (ablation) or even complete disintegration of smaller objects, and objects with lower compressive strength can explode. Crewed space vehicles must be slowed to subsonic speeds be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-43A (Hyper - X) Mach 7 Computational Fluid Dynamic (CFD)
The NASA X-43 was an experimental aircraft, experimental Unmanned aerial vehicle, unmanned hypersonic aircraft with multiple planned scale (spatial), scale variations meant to test various aspects of hypersonic flight. It was part of the X-plane (aircraft), X-plane series and specifically of NASA's Hyper-X program. It set several flight airspeed record, airspeed records for jet aircraft. The X-43 is the fastest jet-powered aircraft on record at approximately Mach number, Mach 9.6.Thompson, Elvia, Keith Henry and Leslie Williams"Faster Than a Speeding Bullet: Guinness Recognizes NASA Scramjet."''NASA.'' Retrieved: August 1, 2011. A winged booster rocket with the X-43 placed on top, called a "stack", was drop launched from a Boeing B-52 Stratofortress. After the booster rocket (a modified first stage of the Pegasus (rocket), Pegasus rocket) brought the stack to the target speed and altitude, it was discarded, and the X-43 flew free using its own engine, a scramjet. The first p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerodynamics
Aerodynamics, from grc, ἀήρ ''aero'' (air) + grc, δυναμική (dynamics), is the study of the motion of air, particularly when affected by a solid object, such as an airplane wing. It involves topics covered in the field of fluid dynamics and its subfield of gas dynamics. The term ''aerodynamics'' is often used synonymously with gas dynamics, the difference being that "gas dynamics" applies to the study of the motion of all gases, and is not limited to air. The formal study of aerodynamics began in the modern sense in the eighteenth century, although observations of fundamental concepts such as aerodynamic drag were recorded much earlier. Most of the early efforts in aerodynamics were directed toward achieving Aircraft#Heavier than air – aerodynes, heavier-than-air flight, which was first demonstrated by Otto Lilienthal in 1891. Since then, the use of aerodynamics through mathematical analysis, empirical approximations, wind tunnel experimentation, and computer simu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spaceplane
A spaceplane is a vehicle that can fly and glide like an aircraft in Earth's atmosphere and maneuver like a spacecraft in outer space. To do so, spaceplanes must incorporate features of both aircraft and spacecraft. Orbital spaceplanes tend to be more similar to conventional spacecraft, while sub-orbital spaceplanes tend to be more similar to fixed-wing aircraft. All spaceplanes to date have been rocket-powered but then landed as unpowered gliders. Four types of spaceplanes have successfully launched to orbit, reentered Earth's atmosphere, and landed: the U.S. Space Shuttle, Russian Buran, U.S. X-37, and the Chinese CSSHQ. Another, Dream Chaser, is under development in the U.S. As of 2019 all past, current, and planned orbital vehicles launch vertically on a separate rocket. Orbital spaceflight takes place at high velocities, with orbital kinetic energies typically at least 50 times greater than suborbital trajectories. Consequently, heavy heat shielding is required ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mach Number
Mach number (M or Ma) (; ) is a dimensionless quantity in fluid dynamics representing the ratio of flow velocity past a boundary to the local speed of sound. It is named after the Moravian physicist and philosopher Ernst Mach. : \mathrm = \frac, where: : is the local Mach number, : is the local flow velocity with respect to the boundaries (either internal, such as an object immersed in the flow, or external, like a channel), and : is the speed of sound in the medium, which in air varies with the square root of the thermodynamic temperature. By definition, at Mach1, the local flow velocity is equal to the speed of sound. At Mach0.65, is 65% of the speed of sound (subsonic), and, at Mach1.35, is 35% faster than the speed of sound (supersonic). Pilots of high-altitude aerospace vehicles use flight Mach number to express a vehicle's true airspeed, but the flow field around a vehicle varies in three dimensions, with corresponding variations in local Mach number. The local spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding the National Advisory Committee for Aeronautics (NACA), to give the U.S. space development effort a distinctly civilian orientation, emphasizing peaceful applications in space science. NASA has since led most American space exploration, including Project Mercury, Project Gemini, the 1968-1972 Apollo Moon landing missions, the Skylab space station, and the Space Shuttle. NASA supports the International Space Station and oversees the development of the Orion spacecraft and the Space Launch System for the crewed lunar Artemis program, Commercial Crew spacecraft, and the planned Lunar Gateway space station. The agency is also responsible for the Launch Services Program, which provides oversight of launch operations and countdown management f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transonic
Transonic (or transsonic) flow is air flowing around an object at a speed that generates regions of both subsonic and supersonic airflow around that object. The exact range of speeds depends on the object's critical Mach number, but transonic flow is seen at flight speeds close to the speed of sound (343 m/s at sea level), typically between Mach 0.8 and 1.2. The issue of transonic speed (or transonic region) first appeared during World War II. Pilots found as they approached the sound barrier the airflow caused aircraft to become unsteady. Experts found that shock waves can cause large-scale separation downstream, increasing drag and adding asymmetry and unsteadiness to the flow around the vehicle. Research has been done into weakening shock waves in transonic flight through the use of anti-shock bodies and supercritical airfoils. Most modern jet powered aircraft are engineered to operate at transonic air speeds. Transonic airspeeds see a rapid increase in drag from a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dissociation (chemistry)
Dissociation in chemistry is a general process in which molecules (or ionic compounds such as salts, or complexes) separate or split into other things such as atoms, ions, or radicals, usually in a reversible manner. For instance, when an acid dissolves in water, a covalent bond between an electronegative atom and a hydrogen atom is broken by heterolytic fission, which gives a proton (H+) and a negative ion. Dissociation is the opposite of association or recombination. Dissociation constant For reversible dissociations in a chemical equilibrium :AB A + B the dissociation constant ''K''d is the ratio of dissociated to undissociated compound :K_d = \mathrm where the brackets denote the equilibrium concentrations of the species. Dissociation degree The dissociation degree \alpha is the fraction of original solute molecules that have dissociated. It is usually indicated by the Greek symbol α. More accurately, degree of dissociation refers to the amount of solute dissociated i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron (rocket)
Electron is a two-stage, partially recoverable orbital launch vehicle developed by Rocket Lab, an American aerospace company with a wholly owned New Zealand subsidiary. Electron was developed to service the commercial small satellite launch market. Its Rutherford engines are the first electric-pump-fed engine to power an orbital-class rocket. Electron is often flown with a kickstage or Rocket Lab's Photon spacecraft. Although the rocket was designed to be expendable, Rocket Lab has recovered the first stage twice and is working towards the capability of reusing the booster. The Flight 26 (F26) booster has featured the first helicopter catch recovery attempt. In December 2016, Electron completed flight qualification. The first rocket was launched on 25 May 2017 in a flight called "It's a Test", reaching space but not achieving orbit due to a glitch in communication equipment on the ground. During its second flight on 21 January 2018, Electron reached orbit and deployed three Cu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rocket Lab
Rocket Lab is a public American aerospace manufacturer and launch service provider, with a New Zealand subsidiary. The company operates lightweight Electron orbital rockets, which provide dedicated launches for small satellites. Rocket Lab also plans to build a larger Neutron rocket as early as 2024. Electron rockets have launched 26 times from either Rocket Lab's Launch Complex 1 in New Zealand or the Mid-Atlantic Regional Spaceport in the United States. Two attempts have been made at recovery of the Electron booster. As of 2022, Rocket Lab is developing the bigger Neutron reusable unibody rocket; Photon satellite buses; and Rutherford, Curie , HyperCurie, and Archimedes rocket engines. The company was founded in New Zealand in 2006. By 2009, the successful launch of Ātea-1 made Rocket Lab the first private company in the Southern Hemisphere to reach space. The company then established a headquarter in California in 2013 and developed the expendable Electron rocket. The f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SpaceX Starship
Starship is a Fully-reusable orbital launch vehicle, fully reusable, super heavy-lift launch vehicle under development by SpaceX, an American aerospace company. With more than twice the thrust of the Saturn V, it is designed to be the most powerful launch vehicle ever built and the first with total reusability. The Starship launch vehicle is made up of the SpaceX Starship#Super Heavy booster, Super Heavy first-stage booster and the SpaceX Starship#Starship spacecraft, Starship second stage. The second stage functions as a self-contained spacecraft for carrying crew or cargo once in orbit. Both stages are powered by Raptor engines that burn liquid oxygen and liquid methane propellants in a highly efficient, full-flow staged combustion power cycle. Both rocket stages are designed to be reused by landing vertically at the launch pad or at a separate platform. In its fully reusable configuration, Starship has a payload capacity of to low Earth orbit and is designed to be flown mul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SpaceX
Space Exploration Technologies Corp. (SpaceX) is an American spacecraft manufacturer, launcher, and a satellite communications corporation headquartered in Hawthorne, California. It was founded in 2002 by Elon Musk with the stated goal of reducing space transportation costs to enable the colonization of Mars. The company manufactures the Falcon 9, Falcon Heavy, and Starship launch vehicles, several rocket engines, Cargo Dragon and Crew Dragon spacecraft, and Starlink communications satellites. SpaceX is developing a satellite internet constellation named Starlink to provide commercial internet service. In January 2020, the Starlink constellation became the largest satellite constellation ever launched, and as of December 2022 comprises over 3,300 small satellites in orbit. The company is also developing Starship, a privately funded, fully reusable, super heavy-lift launch system for interplanetary and orbital spaceflight. It is intended to become SpaceX's primary orbi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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