引力弹弓速度计算器
使用此引力弹弓速度计算器快速获得准确的计算结果。
Max Speed Change
18,483.77 m/s
Max Speed Change vs Planet Orbital Velocity
公式
## Gravity Assist (Slingshot) Effect A spacecraft flying past a planet can gain or lose speed by exchanging momentum with the planet. ### Maximum Speed Change **dv = 2 * v_planet * sin(theta/2)** - *v_planet* = planet's orbital velocity around the Sun - *theta* = total bending angle of the flyby trajectory The theoretical maximum (theta = 180 degrees) gives dv = 2 * v_planet.
计算示例
Jupiter flyby: v_planet = 13 070 m/s, bending angle = 90 degrees.
- 01dv = 2 * v_planet * sin(theta/2)
- 02dv = 2 * 13070 * sin(45 deg)
- 03dv = 26140 * 0.7071
- 04dv = 18 483 m/s = 18.48 km/s
常见问题
Does the planet lose energy in a gravity assist?
Yes, but by an immeasurably tiny amount. The planet's enormous mass makes its velocity change negligible.
Can gravity assists slow a spacecraft down?
Yes. By flying in front of the planet (against its orbital motion), the spacecraft transfers energy to the planet and slows down. This was used by Messenger at Venus.
Why is Jupiter the best planet for gravity assists?
Jupiter has the highest orbital velocity times the largest gravity well, offering the most speed change per flyby.