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Cytherocentric Orbit
A Cytherocentric orbit is an orbit around the planet Venus. Venus has no moon, but several man-made objects orbit the planet. The name is analogous to the term geocentric orbit for an orbit around Earth and heliocentric orbit for an orbit around the Sun. The apsides of an Cytherocentric orbit are pericytherion, the pericenter (analogous to perigee), and the apocenter is named apocytherion (analogous to apogee). Etymology The ''Cythero'' prefix is derived from Kythira or "Cythera." In Greek mythology, Cythera was an island associated with the goddess Aphrodite, who is the equivalent of the Roman goddess Venus. Therefore, naming an orbit around Venus "cytherocentric" is a way of referencing Venus' association with this goddess. Satellites in Cytherocentric orbit Venera 9 was the first satellite to achieve Venus orbit in 20 October 1975. Akatsuki was the latest probe to achieve Venus orbit in 2015. Eight probes have achieved Venus orbit: * 4 Soviet Union probes, Venera 9, V ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animation Of Akatsuki Trajectory Around Venus
Animation is a filmmaking technique whereby image, still images are manipulated to create Motion picture, moving images. In traditional animation, images are drawn or painted by hand on cel, transparent celluloid sheets to be photographed and exhibited on film. Animation has been recognised as an artistic medium, specifically within the Entertainment#Industry, entertainment industry. Many animations are either traditional animations or computer animations made with computer-generated imagery (CGI). Stop motion animation, in particular claymation, has continued to exist alongside these other forms. Animation is contrasted with live action, although the two do not exist in isolation. Many moviemakers have produced Live-action animation, films that are a hybrid of the two. As CGI increasingly Photorealism, approximates photographic imagery, filmmakers can easily Compositing, composite 3D animations into their film rather than using practical effects for showy visual effects (VFX). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Venera 10
Venera 10 ( meaning ''Venus 10''), or 4V-1 No. 661, was a Soviet uncrewed space mission to Venus. It consisted of an orbiter and a lander. It was launched on June 14, 1975, 03:00:31 UTC and had a mass of 5033 kg (11096 lb). Orbiter When the mission launched, the Soviet Union only disclosed that the mission's objective was to explore Venus and the surrounding space. Western sources speculated that the spacecraft contained a lander. The orbiter entered Venus orbit on October 23, 1975. Its mission was to serve as a communications relay for the lander and to explore cloud layers and atmospheric parameters with several instruments and experiments: * 1.6–2.8 μm IR Spectrometer * 8–28 μm IR Radiometer * 352 nm UV Photometer * 2 Photopolarimeters (335–800 nm) * 300–800 nm Spectrometer * Lyman-α H/D Spectrometer * Bistatic radar mapping * CM, DM radio occultations * Triaxial Magnetometer * 345–380 nm UV Camera * 355–445 nm Camera * 6 E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delta-v
Delta-''v'' (also known as "change in velocity"), symbolized as and pronounced , as used in spacecraft flight dynamics, is a measure of the impulse per unit of spacecraft mass that is needed to perform a maneuver such as launching from or landing on a planet or moon, or an in-space orbital maneuver. It is a scalar that has the units of speed. As used in this context, it is not the same as the physical change in velocity of said spacecraft. A simple example might be the case of a conventional rocket-propelled spacecraft, which achieves thrust by burning fuel. Such a spacecraft's delta-''v'', then, would be the change in velocity that spacecraft can achieve by burning its entire fuel load. Delta-''v'' is produced by reaction engines, such as rocket engines, and is proportional to the thrust per unit mass and the burn time. It is used to determine the mass of propellant required for the given maneuver through the Tsiolkovsky rocket equation. For multiple maneuvers, delta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerobraking
Aerobraking is a spaceflight maneuver that reduces the high point of an elliptical orbit (apoapsis) by flying the vehicle through the atmosphere at the low point of the orbit (periapsis). The resulting drag slows the spacecraft. Aerobraking is used when a spacecraft requires a low orbit after arriving at a body with an atmosphere, as it requires less fuel than using propulsion to slow down. Method When an interplanetary vehicle arrives at its destination, it must reduce its velocity to achieve orbit or to land. To reach a low, near-circular orbit around a body with substantial gravity (as is required for many scientific studies), the required velocity changes can be on the order of kilometers per second. Using propulsion, the rocket equation dictates that a large fraction of the spacecraft mass must consist of fuel. This reduces the science payload and/or requires a large and expensive rocket. Provided the target body has an atmosphere, aerobraking can be used to reduce fuel re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spacecraft Attitude Control
Spacecraft attitude control is the process of controlling the orientation of a spacecraft (vehicle or satellite) with respect to an inertial frame of reference or another entity such as the celestial sphere, certain fields, and nearby objects, etc. Controlling vehicle attitude requires actuators to apply the torques needed to orient the vehicle to a desired attitude, and algorithms to command the actuators based on the current attitude and specification of a desired attitude. Before and during attitude control can be performed, spacecraft attitude determination must be performed, which requires sensors for absolute or relative measurement. The broader integrated field that studies the combination of sensors, actuators and algorithms is called ''guidance, navigation and control'', which also involves non-attitude concepts, such as position determination and navigation. Motivation A spacecraft's attitude must typically be stabilized and controlled for a variety of reasons. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elliptic Orbit
In astrodynamics or celestial mechanics, an elliptical orbit or eccentric orbit is an orbit with an eccentricity of less than 1; this includes the special case of a circular orbit, with eccentricity equal to 0. Some orbits have been referred to as "elongated orbits" if the eccentricity is "high" but that is not an explanatory term. For the simple two body problem, all orbits are ellipses. In a gravitational two-body problem, both bodies follow similar elliptical orbits with the same orbital period around their common barycenter. The relative position of one body with respect to the other also follows an elliptic orbit. Examples of elliptic orbits include Hohmann transfer orbits, Molniya orbits, and tundra orbits. Velocity Under standard assumptions, no other forces acting except two spherically symmetrical bodies (m_1) and (m_2), the orbital speed (v\,) of one body traveling along an elliptical orbit can be computed from the vis-viva equation as: :v = \sqrt where: * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ABC News (United States)
ABC News is the news division of the American television network ABC. Its flagship program is the daily evening newscast '' ABC World News Tonight with David Muir''; other programs include morning news-talk show '' Good Morning America'', ''Nightline'', '' 20/20'', and Sunday morning political affairs program '' This Week with George Stephanopoulos''. The network also includes daytime talk shows '' The View'', '' Live with Kelly and Mark'', and '' Tamron Hall''. In addition to the division's television programs, ABC News has radio and digital outlets, including ABC News Radio and ABC News Live, plus various podcasts hosted by ABC News personalities. History 20th-century origins ABC began in 1943 as the NBC Blue Network, a radio network that was spun off from NBC, as ordered by the Federal Communications Commission (FCC) in 1942. The reason for the order was to expand competition in radio broadcasting in the United States, specifically news and political broadcasting, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flyby (spaceflight)
A flyby () is a spaceflight operation in which a spacecraft passes in proximity to another body, usually a target of its space exploration mission and/or a source of a gravity assist (also called ''swing-by'') to impel it towards another target. Spacecraft which are specifically designed for this purpose are known as flyby spacecraft, although the term has also been used in regard to asteroid flybys of Earth for example. Important parameters are the time and distance of closest approach. Spacecraft flyby Flyby maneuvers can be conducted with a planet, a natural satellite or a non-planetary object such as a small Solar System body. Planetary flybys have occurred with Mars or Earth for example: * List of Earth flybys * Mars flyby An example of a comet flyby is when International Cometary Explorer (formerly ISEE-3) passed about from the nucleus of Comet Giacobini-Zinner in September 1985. Another application of the flyby is of Earth's Moon, usually called a lunar flyby. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Venus Express
''Venus Express'' (VEX) was the first Venus exploration mission of the European Space Agency (ESA). Launched in November 2005, it arrived at Venus in April 2006 and began continuously sending back science data from its polar orbit around Venus. Equipped with seven scientific instruments, the main objective of the mission was the long term observation of the Venusian atmosphere. The observation over such long periods of time had never been done in previous missions to Venus, and was key to a better understanding of the atmospheric dynamics. ESA concluded the mission in December 2014. History The mission was proposed in 2001 to reuse the design of the ''Mars Express'' mission. However, some mission characteristics led to design changes: primarily in the areas of thermal control, communications and electrical power. For example, since Mars is approximately twice as far from the Sun as Venus, the radiant heating of the spacecraft is four times greater for ''Venus Express'' than '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JAXA
The is the Japanese national air and space agency. Through the merger of three previously independent organizations, JAXA was formed on 1 October 2003. JAXA is responsible for research, technology development and launch of satellites into orbit, and is involved in many more advanced missions such as asteroid exploration and possible human exploration of the Moon. Its motto is ''One JAXA'' and its corporate slogan is ''Explore to Realize'' (formerly ''Reaching for the skies, exploring space''). History On 1 October 2003, three organizations were merged to form the new JAXA: Japan's Institute of Space and Astronautical Science (ISAS), the National Aerospace Laboratory of Japan (NAL), and National Space Development Agency of Japan (NASDA). JAXA was formed as an Independent Administrative Institution administered by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) and the Ministry of Internal Affairs and Communications (MIC). Before the mer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pioneer Venus 1
The ''Pioneer Venus Orbiter'', also known as ''Pioneer Venus 1'' or ''Pioneer 12'', was a mission to Venus conducted by NASA as part of the Pioneer Venus project. Launched in May 1978 atop an Atlas-Centaur rocket, the spacecraft was inserted into an elliptical orbit around Venus on December 4, 1978. It returned data from Venus until October 1992. The spacecraft conducted radar altimetry observations allowing the first global topographic map of the Venusian surface to be constructed. Spacecraft Manufactured by Hughes Aircraft Company, the ''Pioneer Venus Orbiter'' was based on the HS-507 bus. The spacecraft was a flat cylinder, in diameter and long. All instruments and spacecraft subsystems were mounted on the forward end of the cylinder, except the magnetometer, which was at the end of a boom. A solar array extended around the circumference of the cylinder. A despun dish antenna provided S and X band communication with Earth. A Star 24 solid rocket motor was integrated int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magellan (spacecraft)
The ''Magellan'' spacecraft was a robotic space probe launched by NASA on May 4, 1989. Its mission objectives were to map the surface of Venus by using synthetic-aperture radar and to measure the planetary gravitational field. The ''Magellan'' probe was the first interplanetary mission to be launched from the Space Shuttle, the first one to use the Inertial Upper Stage booster, and the first spacecraft to test aerobraking as a method for circularizing its orbit. ''Magellan'' was the fifth successful NASA mission to Venus, and it ended an eleven-year gap in U.S. interplanetary probe launches. History Beginning in the late 1970s, scientists advocated for a radar mapping mission to Venus. They first sought to construct a spacecraft named the '' Venus Orbiting Imaging Radar'' (VOIR), but it became clear that the mission would be beyond the budget constraints during the ensuing years. The VOIR mission was canceled in 1982. A simplified radar mission proposal was recommended ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
