gravidéviation

CONT: Planetary swing-by maneuver [can be defined as] the encounter between a moving spacecraft and a moving planet or moon, affecting the spacecraft's motion like an elastic collision (in which no energy is lost to heat). Depending on the details of the encounter, the spacecraft can gain or lose appreciable amounts of energy, and appreciable changes in the direction of its motion can result. Swing-by maneuvers with the Moon have been used to reach the L1 Lagrangian point; fly-by maneuvers with he planets have played an essential role in space missions exploring the solar system. Lunar fly-by is similar and is also used.
OBS: Plural is ""swing-bys"", ""swingbys"" or ""swing bys"".