Noun
(spaceflight) a trajectory that passes close to a planetary body in order to gain energy from its gravitational field
Source: WordNetgravity-assist
Those two missions were trail blazers (radiation environment, new moons, gravity-assist flybys) for the planners of the more complex Voyager 1 and Voyager 2 missions, launched five years later. Source: Internet
In December 1992, during Galileo' s second gravity-assist planetary flyby of Earth, another groundbreaking experiment was performed. Source: Internet