比轨道能量计算器
使用此比轨道能量计算器快速获得准确的计算结果。
m
kg
Specific Orbital Energy
-29,432,232 J/kg
Specific Orbital Energy vs Semi-Major Axis
公式
## Specific Orbital Energy **epsilon = -G M / (2a)** - Negative energy = bound (elliptical) orbit - Zero = parabolic escape - Positive = hyperbolic trajectory This quantity is constant along the entire Keplerian orbit.
计算示例
ISS orbit with semi-major axis a = 6 771 km around Earth.
- 01epsilon = -G M / (2a)
- 02G M = 3.986e14
- 032a = 1.354e7
- 04epsilon = -3.986e14 / 1.354e7 ≈ -29.4 MJ/kg
常见问题
Why is bound orbit energy negative?
The gravitational potential energy (negative) exceeds the kinetic energy, so the total is negative and the body cannot escape.
How does energy relate to orbit shape?
Energy depends only on the semi-major axis, not eccentricity. A circle and an elongated ellipse with the same a have the same energy.
What happens at exactly zero energy?
The orbit is parabolic, corresponding to escape velocity at every point.