A planetary flyby is the act of sending a
space probe
A space probe is an artificial satellite that travels through space to collect scientific data. A space probe may orbit Earth; approach the Moon; travel through interplanetary space; flyby, orbit, or land or fly on other planetary bodies; or ent ...
past a
planet
A planet is a large, rounded astronomical body that is neither a star nor its remnant. The best available theory of planet formation is the nebular hypothesis, which posits that an interstellar cloud collapses out of a nebula to create a you ...
or a
dwarf planet
A dwarf planet is a small planetary-mass object that is in direct orbit of the Sun, smaller than any of the eight classical planets but still a world in its own right. The prototypical dwarf planet is Pluto. The interest of dwarf planets to p ...
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
Mariner 2 (Mariner-Venus 1962), an American space probe to Venus, was the first robotic space probe to conduct a successful planetary encounter. The first successful spacecraft in the NASA Mariner program, it was a simplified version of the Bl ...
zoomed by the planet
Venus
Venus is the second planet from the Sun. It is sometimes called Earth's "sister" or "twin" planet as it is almost as large and has a similar composition. As an interior planet to Earth, Venus (like Mercury) appears in Earth's sky never fa ...
.
Planetary flybys are commonly used as
gravity assist
In orbital mechanics and aerospace engineering, a gravitational slingshot, gravity assist maneuver, or swing-by is the use of the relative movement (e.g. orbit around the Sun) and gravity of a planet or other astronomical object to alter the p ...
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 that was launched as a part of NASA's New Frontiers program. Engineered by the Johns Hopkins University Applied Physics Laboratory (APL) and the Southwest Research ...
), flybys are the primary objectives of a mission in of themselves.
A relatively recent example of a flyby spacecraft is ''
New Horizons
''New Horizons'' is an Interplanetary spaceflight, interplanetary space probe that was launched as a part of NASA's New Frontiers program. Engineered by the Johns Hopkins University Applied Physics Laboratory (APL) and the Southwest Research ...
,'' 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 mass more than two and a half times that of all the other planets in the Solar System combined, but ...
,
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 S ...
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
The Kuiper belt () is a circumstellar disc in the outer Solar System, extending from the orbit of Neptune at 30 astronomical units (AU) to approximately 50 AU from the Sun. It is similar to the asteroid belt, but is far larger—20 times ...
on an escape trajectory out of the Solar System.
List of planetary flybys
Gallery
Galileo trajectory Ida.svg, The Galileo flybys featured both purely gravitional assists and scientific experiments
See also
*
Mariner program
The Mariner program was conducted by the American space agency NASA to explore other planets. Between 1962 and late 1973, NASA's Jet Propulsion Laboratory (JPL) designed and built 10 robotic interplanetary probes named Mariner to explore the in ...
*
Mars program
The Mars program was a series of uncrewed spacecraft launched by the Soviet Union between 1960 and 1973. The spacecraft were intended to explore Mars, and included flyby probes, landers and orbiters.
Early Mars spacecraft were small, and launche ...
*
Pioneer program
*
Vega program
The Vega program (Cyrillic: ВеГа) was a series of Venus missions that also took advantage of the appearance of comet 1P/Halley in 1986. ''Vega 1'' and ''Vega 2'' were uncrewed spacecraft launched in a cooperative effort among the Soviet U ...
*
Venera
The Venera (, , which means "Venus" in Russian) program was the name given to a series of space probes developed by the Soviet Union between 1961 and 1984 to gather information about the planet Venus. Ten probes successfully landed on the s ...
*
Voyager program
The Voyager program is an American scientific program that employs two robotic interstellar probes, ''Voyager 1'' and ''Voyager 2''. They were launched in 1977 to take advantage of a favorable alignment of Jupiter and Saturn, to Flyby (spacef ...
*
Zond program
Zond (russian: Зонд, lit=probe) was the name given to two distinct series of Soviet robotic spacecraft launched between 1964 and 1970. The first series, based on the 3MV planetary probe, was intended to gather information about nearby plan ...
*
List of Earth flybys
List of Earth flybys is a list of cases where spacecraft incidentally performed Earth flybys, typically for a gravity assist to another body.
See also
* List of Solar System probes
* Gravity assist
* Planetary flyby
* Mars flyby
A Mars flyby ...
*
Mars flyby
A Mars flyby is a movement of spacecraft passing in the vicinity of the planet Mars, but not entering orbit or landing on it.
Page 15-16 in Chapter 3 of David S. F. Portree's ''Humans to Mars: Fifty Years of Mission Planning, 1950 - 2000,'' NASA ...
*
Timeline of the Space Race
This is a timeline of achievements in Soviet and United States spaceflight, spanning the Cold War era of nationalistic competition known as the Space Race.
This list is limited to first achievements by the USSR and USA which were important d ...
*
Timeline of Solar System exploration
This is a timeline of Solar System exploration ordered by date of spacecraft launch. It includes:
*All spacecraft that have left Earth orbit for the purposes of Solar System exploration (or were launched with that intention but failed), includ ...
Notes
References
{{reflist
Spaceflight
*