文档介绍：航空航天术语：九道 文/周s 每个椭圆有两个焦点。
Kepler's laws were formulated in 1609-1619, which include:
1 ・ The planetary orbits are elliptical.
2・ The nearer the planet is to the Sun, the greater its velocity is.
3・ The square of a planets orbital period is proportional to the cube of its distance from the Sun.
太阳同步轨道 B
Sun Synchronous Orbit
开普勒定律
(SSO)
开普勒定律于1609-1619年提出，其主要内容如下: From 600 to 900 kilometers above the
Earth's surface.
1. 行星轨道是椭圆的。