Lunar Orbit

In astronomy, lunar orbit (also known as a Selenocentric orbit) refers to the orbit of an object around the Moon.

As used in the space program, this refers not to the orbit of the Moon about the Earth, but to orbits by various manned or unmanned spacecraft around the Moon. The altitude at apoapsis (point farthest from the surface) for a lunar orbit is known as apolune, apocynthion or aposelene, while the periapsis (point closest to the surface) is known as perilune, pericynthion or periselene.

Low Lunar orbit (LLO)—orbits below 100 kilometres (62 mi) altitude—are of particular interest in exploration of the moon, but suffer from gravitational perturbation effects that make most unstable, and leave only a few orbital inclinations possible for indefinite frozen orbits, useful for long-term stays in LLO.

Read more about Lunar OrbitUnmanned Spacecraft, Manned Spacecraft, Perturbation Effects

Other articles related to "orbit, lunar orbit, lunar, orbits, lunar orbits":

Low Energy Transfer - History
... in 1991 by the Japanese spacecraft Hiten, which was designed to swing by the moon but not to enter orbit ... subsatellite was released by Hiten on its first swing-by and successfully entered lunar orbit, but suffered a communications failure ... the main Hiten probe to itself enter lunar orbit ...
Saturn C-4
... in 1960 for a three-stage launch vehicle that could launch 99,000 kg (218,000 lb) to Low Earth Orbit and send 32,000 kg (70,000 lb) to the Moon via Trans-Lunar Injection ... It met the initial requirements for a Lunar orbit rendezvous and lunar landing mission ... of sending the 30,000 kg (67,000 lb) Apollo Command/Service Module into lunar orbit, but it would not have been able to carry the 15,000 kg (32,000 lb) Lunar Module as well ...
LK (spacecraft) - Lunniy Korabl Compared To Lunar Module
... was created to be more efficient and less bulky than the Lunar Module (LM) It had a different landing profile It was lighter at only 1/3 the weight of the LM Initially the LK was to have ... To leave lunar orbit and begin descent, the LK used the same braking stage, the Blok D, which put the LK-Soyuz stack into lunar orbit the LM used its landing stage engine (though ... This allowed the same Block to also serve as the ascent stage to return the LK to lunar orbit the LM's landing stage had a dedicated engine for landing For better performance, LK ...
Lunar Orbit - Perturbation Effects
... Gravitational anomalies slightly distorting the orbits of some Lunar Orbiters led to the discovery of mass concentrations (dubbed mascons), beneath the lunar ... These anomalies are significant enough to cause a lunar orbit to change significantly over the course of several days ... Lunar mascons make most low lunar orbits unstable" but there exist four 'frozen orbits' "where a spacecraft can stay in a low lunar orbit indefinitely." The ...
Altair (spacecraft) - Description - Engines
... to be able to descend from an equatorial or high-inclination lunar orbit to a polar landing site, along with bringing it and the Orion spacecraft into lunar orbit, as the Orion spacecraft's ... Altair were meant to serve as testbeds for methane rockets and Sabatier reactors after a permanent lunar base is established ...

Famous quotes containing the words orbit and/or lunar:

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    A bird half wakened in the lunar noon
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