(astrodynamics) A sun-synchronous orbit.

plural of heliosynchronous orbit

A satellite orbit around the Earth within the altitude range of 200 - 2000 km, in which a satellite can communicate with Earth with a small time lag and energy consumption. Abbreviation: LEO.

plural of low Earth orbit

(aerospace) An elliptical orbit used to transfer between two circular orbits of different radii in the same plane.

plural of Hohmann transfer orbit

(space flight) A lunar-resonant orbit about the Earth with a period of 1/2 that of the Moon's (P/2 is an orbit that is approximately a fortnight long)

(algebra) A theorem which states that for each element of a given set that a given group acts on, there is a natural bijection between the orbit of that element and the cosets of the stabilizer subgroup with respect to that element.

(of a black hole) Synonym of photon sphere

(informal, often humorous) The referent of it is dangerous or undesirable and should be eliminated.