halo orbit

Etymology
First used by NASA mission specialist in 1966 for calculated orbits around the Earth-Moon L2 point which required the use of thrusters to be made periodic.

Noun

 * 1)  A periodic, three-dimensional orbit about any one of the Lagrange points L1, L2 or L3 of a two-body gravitational system.
 * 2) * 2013, Yuhui Zhao, Shoucun Hu, Xiyun Hou, Lin Liu, Chapter 39: On Nominal Formation Flying Orbit with a Small Solar System Body, Rongjun Shen, Weiping Qian (editors), Proceedings of the 26th Conference of Spacecraft TT&C Technology in China,, Springer, Lecture Notes in Electrical Engineering 187, page 395,
 * If the ratio of the amplitude in x-direction to $$\gamma_1$$ keeps unchanged (=0.155), the periods of halo orbits are almost the same (about 190 days). As a result of the stability of CRTBP and the dynamics of halo orbit formation, nominal halo orbits do not exist if the ratio is too large or too small.
 * If the ratio of the amplitude in x-direction to $$\gamma_1$$ keeps unchanged (=0.155), the periods of halo orbits are almost the same (about 190 days). As a result of the stability of CRTBP and the dynamics of halo orbit formation, nominal halo orbits do not exist if the ratio is too large or too small.

Translations

 * French: orbite de halo
 * German: Halo-Orbit
 * Italian: orbita halo