A planetary flyby is the act of sending a

space probe Uncrewed spacecraft or robotic spacecraft are spacecraft without people on board. Uncrewed spacecraft may have varying levels of autonomy from human input, such as remote control, or remote guidance. They may also be autonomous, in which th ...

past a

planet A planet is a large, Hydrostatic equilibrium, rounded Astronomical object, astronomical body that is generally required to be in orbit around a star, stellar remnant, or brown dwarf, and is not one itself. The Solar System has eight planets b ...

or a

dwarf planet A dwarf planet is a small planetary-mass object that is in direct orbit around the Sun, massive enough to be hydrostatic equilibrium, gravitationally rounded, but insufficient to achieve clearing the neighbourhood, orbital dominance like the ...

close enough to record scientific data. This is a subset of the overall concept of a flyby in spaceflight. The first flyby of another planet with a functioning spacecraft took place on December 14, 1962, when Mariner 2 zoomed by the planet

Venus Venus is the second planet from the Sun. It is often called Earth's "twin" or "sister" planet for having almost the same size and mass, and the closest orbit to Earth's. While both are rocky planets, Venus has an atmosphere much thicker ...

. Planetary flybys are commonly used as

gravity assist A gravity assist, gravity assist maneuver, swing-by, or generally a gravitational slingshot in orbital mechanics, is a type of spaceflight flyby (spaceflight), flyby which makes use of the relative movement (e.g. orbit around the Sun) and gra ...

maneuvers to "slingshot" a space probe toward its primary target without expending fuel, but in some cases (such as with

New Horizons ''New Horizons'' is an Interplanetary spaceflight, interplanetary space probe launched as a part of NASA's New Frontiers program. Engineered by the Johns Hopkins University Applied Physics Laboratory (APL) and the Southwest Research Institut ...

), flybys are the primary objectives of a mission in of themselves. Flybys modify the direction of the probe and adds to its heliocentric velocity. A relatively recent example of a flyby spacecraft is ''

,'' which performed flyby maneuvers of

Jupiter Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a Jupiter mass, mass more than 2.5 times that of all the other planets in the Solar System combined a ...

Pluto Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of Trans-Neptunian object, bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the Su ...

and its moons in the 21st century. The flyby of Jupiter, used as a gravity assist, allowed the craft to reach Pluto at high velocity without the complications of slowing down, after which it proceeded further into the Kuiper Belt on an escape trajectory out of the Solar System.

List of planetary flybys

Gallery

Galileo trajectory Ida.svg, The Galileo flybys featured both purely gravitational assists and scientific experiments.

Notes

References

{{reflist Spaceflight *

List of planetary flybys

Gallery

See also

Notes

References