1, The viewpoint is perpendicular to the orbital plane.

2, Because our Earth is in the orbital plane of both stars and the planet, each body is seen to eclipse the others at different times, producing noticeable drop offs in the amount of light seen.

3, The optimization performance index is to maximize the orbital plane change, and the optimal lift and bank control law are obtained.

4, Conversely, astrometry works best when a planetary system is "face-on" when seen from Earth, because then the star's movements in the orbital plane are most pronounced.

5, By considering the impact of perturbation, orbital characteristics are researched mainly from three aspects including precession of orbital plane, change of orbital inclination and rotation of apogee.

6, One temple two months prior to launch Shenzhou VIII, how to control the "Temple" after two months and "God eight" in the same orbital plane, the relationship to the rendezvous and docking success.

7, First, we know that the planets all orbit close to the earth's orbital plane, the ecliptic.

8, A useful ellipse equation in relation the trajectory of a station keeping point in an orbital plane is obtained.