Flyby (spaceflight)

A flyby (/ˈflaɪbaɪ/) is a spaceflight operation in which a spacecraft passes in proximity to another body, usually a target of its space exploration mission and/or a source of a gravity assist (also called swing-by) to impel it towards another target.^[1] Spacecraft which are specifically designed for this purpose are known as flyby spacecraft, although the term has also been used in regard to asteroid flybys of Earth for example.^[2][3] Important parameters are the time and distance of closest approach.^[4]