Get Flyby Spaceflight essential facts below. View Videos or join the Flyby Spaceflight discussion. Add Flyby Spaceflight to your PopFlock.com topic list for future reference or share this resource on social media.
A flyby is a spaceflight operation in which a spacecraft passes in close proximity to another body, usually a target of its space exploration mission and/or a source of a gravity assist to impel it towards another target. 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. Important parameters are the time and distance of closest approach.
Another application of the flyby is of Earth's Moon, usually called a lunar flyby.
The Artemis 2 mission has a mission design that would include a lunar flyby.
Illustration of the MarCO 6U cubesat relay flyby probes and technology demonstrators for the Mars InSight lander; the flybys provided bent pipe communication support during the landing in 2018
In regards to Mars flybys, a related concept is a Mars flyby rendezvous, where a spacecraft does not enter orbit but rendezvous before or after a flyby of the planet with another spacecraft. Mars flyby rendezvous was evaluated at NASA's Manned Spacecraft Center in the 1960s. At that time NASA developed designs for a combination of a Mars lander, short-stay surface habitat, and ascent vehicle called a Mars Excursion Module (MEM); the ascent stage performed the rendezvous with another spacecraft that did a flyby of Mars without entering orbit or landing. Compared to MOR, a flyby rendezvous means one spacecraft does not have to orbit Mars, so the resources needed on a return journey to Earth are not taken in and out of Mars orbit for example. (See also Mars cycler)
Mariner IV flyby of Mars in July 1965 returned more accurate atmospheric data about Mars and much closer views of its surface then previously.
In 2018, the twin Mars Cube One performed a flyby to relay communication for InSight lander EDL (they were launched towards Mars with the cruise stage carrying the InSight lander). Both MarCOs reached Mars and successfully relayed data during the Entry, Descent, and Landing phase of Insight on November 26, 2018.
On the night of December 31, 2018 to the morning of January 1, 2019 New Horizons performed the most distant flyby to date, of the Kuiper belt object Arrokoth. New Horizons previously did a flyby of Pluto in July 2015, and that was at about 32.9 AU (astronomical units) from the Sun, while the New Year's Day 2019 flyby of the Kuiper object Arrokoth was at 43.6 AU. 
Diagram of the trajectory of New Horizons during its flyby of Pluto
In 2010, the Deep Impact spacecraft, on the EPOXI mission did a flyby of comet Hartley 2.
Flyby of comet Hartley 2 on Nov. 4, 2010 (EPOXI mission)
During an asteroid flyby of Earth, sometimes they are imaged by radar. Animation of , which had an Earth flyby in 2017
Flyby is also sometimes loosely used to describe when, for example, an asteroid approaches and coasts by the Earth.
This was also the term for when a comet did a flyby of Mars in 2014.
P/2016 BA14 was radar imaged at distance of 2.2 million miles (9 lunar distances) from Earth in 2016, during its flyby. This enabled the size of the nucleus to be calculated to about 1 km in diameter.
On December 16, 2018 the short period comet 46P/Wirtanen had its closest approach of Earth, coming within 7.1 million miles (one of its closest approaches to Earth).
^Bagenal, F.; Delamere, P. A.; Elliott, H. A.; Hill, M. E.; Lisse, C. M.; McComas, D. J.; McNutt Jr, R. L.; Richardson, J. D.; Smith, C. W.; Strobel, D. F. (2015). "Solar wind at 33 AU: Setting bounds on the Pluto interaction for New Horizons". Journal of Geophysical Research: Planets. 120 (9): 1497-1511. arXiv:1509.04660. doi:10.1002/2015JE004880.