Kostenloser Gravity Assist Speed Rechner
Schätzen Sie den speed change aus a planetary gravity assist (slingshot). Kostenloser space exploration Rechner.
Max Speed Change
18,483.77 m/s
Max Speed Change vs Planet Orbital Velocity
Formel
## 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.
Lösungsbeispiel
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
Häufig Gestellte Fragen
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.