Patent ID: 7744036

Claim:
An orbit design method for placing a spacecraft in an orbit comprising: identifying a celestial system comprising a first body and a second body in a cosmic space where both bodies turn around a barycenter, the barycenter being a center of masses of the two bodies, both bodies in a circular orbit, and a spacecraft equipped with a propulsion mechanism residing on a first line connecting the two bodies, around an equilibrium point near the second body; and implementing a coordinate system with respect to the celestial system such that the first line connecting the first and second celestial bodies is made a fixed axis, a second axis perpendicular to the fixed axis is included on a revolution plane of the two bodies, and a second line perpendicular to the revolution plane is made a third axis, with a plane spanned by both the fixed and third axes being made a first plane, where the spacecraft is located close to a Lagrange point on the fixed axis, where a gravity from the two bodies is balanced with a centrifugal force resulting from a revolution motion, wherein the propulsion mechanism of the spacecraft is continuously activated during orbit such that a propulsion force vector having a specified fixed magnitude is allowed to rotate at a specified fixed angular velocity so as to make the orbit of the spacecraft projected onto a second plane depict a non-Keplerian and circular halo orbit in a form of a closed small-radius circuit maintaining a passive stability location characteristic associated with a Lissajous orbit, the second plane being a plane perpendicular to any arbitrary line on the first plane spanned by both the fixed axis and the third axis.