halo orbit

== English == === Etymology === First used by NASA mission specialist Robert W. Farquhar in 1966 for calculated orbits around the Earth–Moon L2 point which required the use of thrusters to be made periodic. === Noun === halo orbit (plural halo orbits) (orbital mechanics) A periodic, three-dimensional orbit about any one of the Lagrange points L1, L2 or L3 of a two-body gravitational system. 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, Tsinghua University Press, Springer, Lecture Notes in Electrical Engineering 187, page 395, If the ratio of the amplitude in x-direction to γ 1 {\displaystyle \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. Hypernym: orbit Hyponyms: near-rectilinear halo orbit, quasi-halo orbit, quasi-periodic halo orbit ==== Translations ==== === See also === Lissajous orbit Lyapunov orbit === Further reading === Three-body problem on Wikipedia.Wikipedia Lagrange point on Wikipedia.Wikipedia