- Lissajous orbit
In

orbital mechanics , a**Lissajous orbit**is a quasi-periodic orbital trajectory that an object can follow around a collinearlibration point (Lagrangian point ) of a three-body system without requiring any propulsion. Lyapunov orbits around a libration point are curved paths that lie "entirely" in the plane of the two primary bodies. In contrast, Lissajous orbits include components in this plane and perpendicular to it, and follow aLissajous curve .Halo orbit s also include components perpendicular to the plane, but they are periodic, while Lissajous orbits are not.In practice, any orbit around a collinear libration point is dynamically unstable, meaning small departures from equilibrium grow exponentially over time. As a result, spacecraft in libration point orbits must use their propulsion systems to perform

orbital stationkeeping .Several missions have used Lissajous trajectories. ACE at Sun-Earth L

_{1}and WMAP at Sun-Earth L_{2}.**References*** http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=34699

* http://www.daviddarling.info/encyclopedia/L/Lissajous_orbit.html

* http://sci2.esa.int/interactive/media/flashes/5_5_1.htm**External links***

*Wikimedia Foundation.
2010.*

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**Lissajous**— may refer to* Jules Antoine Lissajous (1822 1880), French mathematician. * Lissajous curve (or Lissajous figure), a mathematical figure showing a type of harmonic motion. * Lissajous orbit, an orbital trajectory resembling a Lissajous curve … Wikipedia**Orbit**— This article is about orbits in celestial mechanics, due to gravity. For other uses, see Orbit (disambiguation). A satellite orbiting the Earth has a tangential velocity and an inward acceleration … Wikipedia**Orbit of the Moon**— Not to be confused with Lunar orbit in the sense of a selenocentric orbit, that is, an orbit around the Moon The Moon completes its orbit around the Earth in approximately 27.3 days (a sidereal month). The Earth and Moon orbit about their… … Wikipedia**Orbit equation**— In astrodynamics an orbit equation defines the path of orbiting body around central body relative to , without specifying position as a function of time. Under standard assumptions, a body moving under the influence of a force, directed to a… … Wikipedia**Orbit phasing**— In astrodynamics orbit phasing is the adjustment of the time position of spacecraft along its orbit, usually described as adjusting the orbiting spacecraft s true anomaly. This is predominantly used in satellite positioning, especially if the… … Wikipedia**Orbite de Lissajous**— autour du point de Lagrange 2. En mécanique spatiale, une orbite de Lissajous désigne une trajectoire orbitale quasi périodique qu un objet céleste parcourt sans propulsion autour d un point de Lagrange d un système à trois corps. Les orbites de… … Wikipédia en Français**Halo orbit**— A halo orbit is a periodic, three dimensional orbit near the L1, L2, or L3 Lagrange points in the three body problem of orbital mechanics. A spacecraft in a halo orbit does not technically orbit the Lagrange point itself (which is just an… … Wikipedia**Geocentric orbit**— Earth orbit redirects here. For the motion of the Earth around the Sun, see Earth s orbit. Earth orbiter redirects here. For the shuttle simulator, see Earth Orbiter 1. The following words may have more than one definition or other non Earth… … Wikipedia**Geostationary orbit**— Geostationary orbit.To an observer on the rotating Earth (fixed point on the Earth), the satellite appears stationary in the sky. A red satellite is also geostationary above its own point on Earth. Top Down View … Wikipedia**Molniya orbit**— For other uses, see Molniya (disambiguation). Figure 1: The Molniya orbit. Usually the period from perigee + 2 hours to perigee + 10 hours is used to transmit to the northern hemisphere Molniya orbit is a type of highly elliptical orbit with an… … Wikipedia