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Gridded Ion Thruster
The gridded ion thruster is a common design for ion thrusters, a highly efficient low-thrust spacecraft propulsion method running on electrical power by using high-voltage grid electrodes to accelerate ions with electrostatic forces. History The ion engine was first demonstrated by German-born NASA scientist Ernst Stuhlinger, and developed in practical form by Harold R. Kaufman at NASA Lewis (now Glenn) Research Center from 1957 to the early 1960s. The use of ion propulsion systems were first demonstrated in space by the NASA Lewis " Space Electric Rocket Test" (SERT) I and II.J. S. Sovey, V. K. Rawlin, and M. J. Patterson, "Ion Propulsion Development Projects in U. S.: Space Electric Rocket Test 1 to Deep Space 1", ''Journal of Propulsion and Power, Vol. 17'', No. 3, May–June 2001, pp. 517-526. These thrusters used mercury as the reaction mass. The first was SERT-1, launched July 20, 1964, which successfully proved that the technology operated as predicted in space. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrostatic Ion Thruster-en
Electrostatics is a branch of physics that studies electric charges at rest ( static electricity). Since classical times, it has been known that some materials, such as amber, attract lightweight particles after rubbing. The Greek word for amber, (), was thus the source of the word 'electricity'. Electrostatic phenomena arise from the forces that electric charges exert on each other. Such forces are described by Coulomb's law. Even though electrostatically induced forces seem to be rather weak, some electrostatic forces are relatively large. The force between an electron and a proton, which together make up a hydrogen atom, is about 36 orders of magnitude stronger than the gravitational force acting between them. There are many examples of electrostatic phenomena, from those as simple as the attraction of plastic wrap to one's hand after it is removed from a package, to the apparently spontaneous explosion of grain silos, the damage of electronic components during manufact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specific Impulse
Specific impulse (usually abbreviated ) is a measure of how efficiently a reaction mass engine (a rocket using propellant or a jet engine using fuel) creates thrust. For engines whose reaction mass is only the fuel they carry, specific impulse is exactly proportional to the effective exhaust gas velocity. A propulsion system with a higher specific impulse uses the mass of the propellant more efficiently. In the case of a rocket, this means less propellant needed for a given delta-v, so that the vehicle attached to the engine can more efficiently gain altitude and velocity. In an atmospheric context, specific impulse can include the contribution to impulse provided by the mass of external air that is accelerated by the engine in some way, such as by an internal turbofan or heating by fuel combustion participation then thrust expansion or by external propeller. Jet engines breathe external air for both combustion and by-pass, and therefore have a much higher specific impulse than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron Gun
An electron gun (also called electron emitter) is an electrical component in some vacuum tubes that produces a narrow, collimated electron beam that has a precise kinetic energy. The largest use is in cathode-ray tubes (CRTs), used in nearly all television sets, computer displays and oscilloscopes that are not flat-panel displays. They are also used in field-emission displays (FEDs), which are essentially flat-panel displays made out of rows of extremely small cathode-ray tubes. They are also used in microwave linear beam vacuum tubes such as klystrons, inductive output tubes, travelling wave tubes, and gyrotrons, as well as in scientific instruments such as electron microscopes and particle accelerators. Electron guns may be classified by the type of electric field generation (DC or RF), by emission mechanism (thermionic, photocathode, cold emission, plasmas source), by focusing (pure electrostatic or with magnetic fields), or by the number of electrodes. Characteristics ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ThrustMe
ThrustMe is a deep tech company that designs miniaturized aerospace thrusters for small satellites, increasing the life of satellites and making them more affordable. The company builds gridded ion thrusters (NPT30) and cold gas thrusters (I2T5). History ThrustMe was founded in 2017 by Ane Aanesland and Dmytro Rafalskyi, who previously worked at the École Polytechnique and CNRS as researchers in plasma physics and electric propulsion. Initially, the startup was incubated in Agoranov. Also in 2017, ThrustMe raised 1.7 million euros for its development. In 2018, ThrustMe received €2.4 million from the European Commission to commercialise electric propulsion for nanosatellites. In 2019, Ane Aanesland received the CNRS innovation medal for her entrepreneurial activities. The same year, SpaceTy and ThrustMe maneuvered for the first time a satellite using iodine as propellant, with a cold-gas thruster. In 2021, ThrustMe, in partnership with SpaceTy, achieved the first in-orbi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Double Asteroid Redirection Test
Double Asteroid Redirection Test (DART) is a NASA space mission aimed at testing a method of planetary defense against near-Earth objects (NEOs). It was designed to assess how much a spacecraft impact deflects an asteroid through its transfer of momentum when hitting the asteroid head-on. The asteroid selected for the test poses no actual threat to Earth and was selected for the convenience of the test. The probe was launched from Earth on 24 November 2021, and on 26 September 2022 intentionally crashed into Dimorphos, the minor-planet moon of the asteroid Didymos. On 11 October, NASA declared DART a success, confirming it had shortened Dimorphos' orbital period around Didymos by about 32 minutes, surpassing the pre-defined success threshold of 73 seconds. DART is a joint project between NASA and the Johns Hopkins Applied Physics Laboratory (APL). The project was funded through NASA's Planetary Defense Coordination Office, managed by NASA's Planetary Missions Program Office a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hayabusa
was a robotic spacecraft developed by the Japan Aerospace Exploration Agency (JAXA) to return a sample of material from a small near-Earth asteroid named 25143 Itokawa to Earth for further analysis. ''Hayabusa'', formerly known as MUSES-C for Mu Space Engineering Spacecraft C, was launched on 9 May 2003 and rendezvoused with Itokawa in mid-September 2005. After arriving at Itokawa, ''Hayabusa'' studied the asteroid's shape, spin, topography, color, composition, density, and history. In November 2005, it landed on the asteroid and collected samples in the form of tiny grains of asteroidal material, which were returned to Earth aboard the spacecraft on 13 June 2010. The spacecraft also carried a detachable minilander, ''MINERVA'', which failed to reach the surface. Mission firsts Other spacecraft, notably ''Galileo'' and ''NEAR Shoemaker'' (both launched by NASA), had visited asteroids before, but the ''Hayabusa'' mission was the first attempt to return an asteroid samp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BepiColombo
BepiColombo is a joint mission of the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA) to the planet Mercury. The mission comprises two satellites launched together: the Mercury Planetary Orbiter (MPO) and ''Mio'' (Mercury Magnetospheric Orbiter, MMO). The mission will perform a comprehensive study of Mercury, including characterization of its magnetic field, magnetosphere, and both interior and surface structure. It was launched on an Ariane 5 rocket on 20 October 2018 at 01:45 UTC, with an arrival at Mercury planned for on 5 December 2025, after a flyby of Earth, two flybys of Venus, and six flybys of Mercury. The mission was approved in November 2009, after years in proposal and planning as part of the European Space Agency's Horizon 2000+ programme; it is the last mission of the programme to be launched. Names ''BepiColombo'' is named after Giuseppe "Bepi" Colombo (1920–1984), a scientist, mathematician and engineer at the University ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GOCE
''Goce'' is an opera composed by Kiril Makedonski (1925–1984), written by Venko Markovski and dedicated to Gotse Delchev. The work was commissioned to be the very first opera performed by the Macedonian National Opera Company. It premiered on May 24, 1954 and it is the first opera to be written in Macedonian. See also *Music of North Macedonia The Macedonian music refers to all forms of music associated with ethnic Macedonians. It share similarities with the music of neighbouring Balkan countries, yet it remains overall distinctive in its rhythm and sound. Folk music The ethnic Macedo ... References Operas Macedonian-language operas 1954 operas {{opera-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ARTEMIS
In ancient Greek mythology and religion, Artemis (; grc-gre, Ἄρτεμις) is the goddess of the hunt, the wilderness, wild animals, nature, vegetation, childbirth, care of children, and chastity. She was heavily identified with Selene, the Moon, and Hecate, another Moon goddess, and was thus regarded as one of the most prominent lunar deities in mythology, alongside the aforementioned two.Smiths.v. Artemis/ref> She would often roam the forests of Greece, attended by her large entourage, mostly made up of nymphs, some mortals, and hunters. The goddess Diana is her Roman equivalent. In Greek tradition, Artemis is the daughter of the sky god and king of gods Zeus and Leto, and the twin sister of Apollo. In most accounts, the twins are the products of an extramarital liaison. For this, Zeus' wife Hera forbade Leto from giving birth anywhere on land. Only the island of Delos gave refuge to Leto, allowing her to give birth to her children. Usually, Artemis i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
European Retrievable Carrier
The European Retrievable Carrier (EURECA) was an unmanned 4.5-tonne satellite with 15 experiments. It was a European Space Agency (ESA) mission and the acronym was derived from Archimedes' bathtub revelation " Eureka!". It was built by the German MBB-ERNO and had automatic material science cells as well as small telescopes for solar observation (including x-ray). It was launched 31 July 1992 by during STS-46, and placed into an orbit at an altitude of . EURECA was retrieved on 1 July 1993 by during STS-57 and returned to Earth. It was designed to fly five times with different experiments but the following flights were cancelled. EURECA is one of the few unmanned space vehicles that have been returned to the Earth unharmed. It has been on display at the Swiss Museum of Transport in Lucerne since 2000. Design EURECA was made of high-strength carbon-fiber struts and titanium nodal points joined together to form a framework of cubic elements. Thermal control on EURECA combine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
