Tutorial: Basic Orbiting (Math)/zh-cn
在基础轨道飞行指南篇中,你了解了轨道飞行的概念以及基本的轨道稳定调整,还拿到了一个轨道列表,可以籍此了解某飞行轨道参数的。现在,假如你的轨道并不在这个表里该怎么办?假如你需要一个特定周期的轨道呢?下面这些公式会在这些场合起作用。
Orbital Speed
The relation between orbital speed and acceleration is given by the formula:
where a is the acceleration due to gravity, v is the horizontal speed, and r is the radius of orbit.
Of course, gravity varies depending on your distance from the planet, so we also need the following formula to determine a based on your altitude:
where g is the acceleration due to gravity at sea level (9.807 m/s2), R is the radius of Kerbin (600 km), and h is the altitude of your orbit.
Note: Since the radius of your orbit r is equal to the radius of Kerbin R plus your altitude h, we can substitute R + h for r.
Now we have two expressions for a, so we set them on opposite sides of an equation and simplify:
Finally, substituting known values for g and R,
Orbital Period
From the basic mechanics formula:
We know v from the above, and d is simply the circumference of a circle with a radius equal to your orbital altitude plus the radius of Kerbin: