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Astronomy

Gravity Assist for Outer Planet Missions

Quick fact

The Voyager 2 spacecraft, launched in 1977, used gravity assists from Jupiter, Saturn, Uranus, and Neptune to visit all four giant outer planets—essentially hitching a ride on each planet's motion to change its path and speed, making the 'Grand Tour' possible without a Saturn-V class rocket.

Why this is interesting

You pour rocket fuel into your tank to fly to Jupiter, but what if you could get a boost from Jupiter itself—without using a drop of fuel?