Flyby (spaceflight)#Natural flyby

{{Also|List of planetary flybys}}

Flyby maneuvers can be conducted with a planet, a natural satellite or a non-planetary object such as a small Solar System body.{{Cite news|url=http://www.spaceflightinsider.com/space-flight-history/our-spaceflight-heritage-ice-the-first-comet-flyby/|title=Our SpaceFlight Heritage: ICE—The first comet flyby|date=2018-09-12|work=SpaceFlight Insider|access-date=2018-11-04|language=en-US|archive-date=2021-12-18|archive-url=https://web.archive.org/web/20211218044204/https://www.spaceflightinsider.com/space-flight-history/our-spaceflight-heritage-ice-the-first-comet-flyby/|url-status=dead}}{{Cite web|url=https://cosmosmagazine.com/space/first-mission-to-mars-mariner-4-s-special-place-in-history|title=First mission to Mars: Mariner 4's special place in history|website=Cosmos|date=13 July 2017|language=en|access-date=2018-11-04|archive-date=2018-11-04|archive-url=https://web.archive.org/web/20181104211250/https://cosmosmagazine.com/space/first-mission-to-mars-mariner-4-s-special-place-in-history|url-status=dead}}

Planetary flybys have occurred with Mars or Earth for example:

• List of Earth flybys
• Mars flyby

An example of a comet flyby is when International Cometary Explorer (formerly ISEE-3) passed about {{convert|4800|mi}} from the nucleus of Comet Giacobini-Zinner in September 1985.{{Cite news|url=http://www.spaceflightinsider.com/space-flight-history/our-spaceflight-heritage-ice-the-first-comet-flyby/|title=Our SpaceFlight Heritage: ICE—The first comet flyby|date=2018-09-12|work=SpaceFlight Insider|access-date=2018-11-04|language=en-US|archive-date=2021-12-18|archive-url=https://web.archive.org/web/20211218044204/https://www.spaceflightinsider.com/space-flight-history/our-spaceflight-heritage-ice-the-first-comet-flyby/|url-status=dead}}

Another application of the flyby is of Earth's Moon, usually called a lunar flyby.{{Cite news|url=https://arstechnica.com/science/2018/09/spacex-says-its-bfr-will-fly-someone-around-the-moon-we-have-questions/|title=SpaceX says its BFR will fly someone around the Moon; we have questions|work=Ars Technica|access-date=2018-11-04|language=en-us}} The Apollo 13 spacecraft had an exploded oxygen tank, and therefore had to flyby around the Moon.{{cite web|work=Apollo Lunar Flight Journal|url=https://history.nasa.gov/afj/ap13fj/08day3-problem.html|title=Day 3: 'Houston, we've had a problem'|date=May 30, 2017|accessdate=August 18, 2019|last1=Woods|first1=W. David|last2=Kemppanen|first2=Johannes|last3=Turhanov|first3=Alexander|last4=Waugh|first4=Lennox J.}} The Artemis 2{{Cite web|url=https://www.esa.int/Our_Activities/Human_Spaceflight/Orion/Exploration_Mission_2|title=Exploration Mission 2|website=esa|language=en-GB|access-date=2019-01-02}} will include a lunar flyby.

File:PIA22316 MarCO InSight.jpg 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.{{cite book|pages=15–16|chapter=Chapter 3: EMPIRE and After|first=David S. F.|last=Portree|title=Humans to Mars: Fifty Years of Mission Planning, 1950 - 2000|series=NASA Monographs in Aerospace History Series|number=21|date=February 2001|publisher=National Aeronautics and Space Administration|chapter-url=https://history.nasa.gov/monograph21/Chapter%203_low.pdf|accessdate=July 18, 2014}} 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 a different 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.{{Cite magazine |url=https://www.wired.com/2012/10/origin-of-the-apollo-shaped-manned-mars-lander-1966/ |title=Origin of the Apollo-shaped Manned Mars Lander (1966) |date=25 October 2012 |magazine=WIRED |access-date=4 March 2018}}

Mariner 6 and Mariner 7 flyby of Mars in 1969 caused another breakthrough in knowledge about the planet.{{Cite web|url=https://www.acs.org/content/acs/en/education/whatischemistry/landmarks/mars-infrared-spectrometer.html|title=Infrared Spectrometer and the Exploration of Mars|website=American Chemical Society|language=en|access-date=2018-12-26}}{{Cite journal|last=Chdse|first=S. C.|date=1969-03-01|title=Infrared radiometer for the 1969 mariner mission to Mars|journal=Applied Optics|volume=8|issue=3|pages=639|doi=10.1364/AO.8.000639|issn=1559-128X|pmid=20072273|bibcode=1969ApOpt...8..639C}} The Mariner 6 & 7 infrared radiometer results from the flyby showed that the atmosphere of Mars was composed mostly of carbon dioxide (CO₂), and they were also able to detect trace amounts of water on the surface of Mars.{{Cite web|url=https://www.acs.org/content/acs/en/education/whatischemistry/landmarks/mars-infrared-spectrometer.html|title=Infrared Spectrometer and the Exploration of Mars|website=American Chemical Society|language=en|access-date=2018-12-26}}

Rosetta,[http://www.esa.int/SPECIALS/Rosetta/SEMWZ5CE8YE_0.html ESA - Rosetta successfully swings-by Mars], swung by around Mars at a distance of 250 km{{Cite web|url=http://news.bbc.co.uk/2/hi/6394141.stm|title=Space probe performs Mars fly-by|date=February 25, 2007|work=BBC News}} and performed a gravity assist. This is the closest flyby of Mars.

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).{{Cite web|url=http://www.planetary.org/blogs/emily-lakdawalla/2018/0501-marco-cubesats-to-mars.html|title=MarCO: CubeSats to Mars!|website=www.planetary.org|language=en|access-date=2018-11-26}} Both MarCOs reached Mars and successfully relayed data during the Entry, Descent, and Landing phase of Insight on November 26, 2018.{{Cite news|url=https://www.space.com/42541-mars-insight-lander-success.html|title=Touchdown on Mars! NASA's InSight Lands to Peer Inside the Red Planet|work=Space.com|access-date=2018-11-26}}

Meanwhile, Tianwen-1 Deployable Camera, imaged Tianwen-1 in on its transit to Mars, in September 2020 and made a flyby of Mars around 10 February, 2021 according to its trajectory thought for Mars, before entering the deep space or a solar orbit.

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.{{Cite web|url=https://www.msn.com/en-us/news/technology/new-horizons-spacecraft-completes-flyby-of-ultima-thule-the-most-distant-object-ever-visited/ar-BBRFdrp|title=MSN|website=MSN}} 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.{{Cite journal |arxiv = 1509.04660|doi = 10.1002/2015JE004880|title = Solar wind at 33 AU: Setting bounds on the Pluto interaction for New Horizons|journal = Journal of Geophysical Research: Planets|volume = 120|issue = 9|pages = 1497–1511|year = 2015|last1 = Bagenal|first1 = F.|last2 = Delamere|first2 = P. A.|last3 = Elliott|first3 = H. A.|last4 = Hill|first4 = M. E.|last5 = Lisse|first5 = C. M.|last6 = McComas|first6 = D. J.|last7 = McNutt Jr|first7 = R. L.|last8 = Richardson|first8 = J. D.|last9 = Smith|first9 = C. W.|last10 = Strobel|first10 = D. F.|bibcode = 2015JGRE..120.1497B|s2cid = 118518239}}{{Cite web|url=http://pluto.jhuapl.edu/Mission/Where-is-New-Horizons/index.php|title=New Horizons|website=pluto.jhuapl.edu|language=en|access-date=2018-10-26}}

File:New Horizons Pluto approach diagram.png during its flyby of Pluto]]

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File:Animation of Cassini trajectory around Saturn.gif }}{{·}}{{legend2|OrangeRed|Enceladus}}{{·}}{{legend2| Gold | Titan}}{{·}}{{legend2|Cyan| Iapetus}}]]

Cassini-Huygens (launched 1997), which orbited Saturn (from 2004–2017) performed flybys of many of Saturn's moons including Titan.{{Cite web|url=http://sci.esa.int/cassini-huygens/36019-titan-a-flyby-closest-approach/|title=Titan A Flyby Closest Approach|website=sci.esa.int|language=en-GB|access-date=2018-11-04}} Cassini-Huygen{{'}}s had its first flyby of Titan in October 2004.{{Cite web|url=http://sci.esa.int/cassini-huygens/36019-titan-a-flyby-closest-approach/|title=Titan A Flyby Closest Approach|website=sci.esa.int|language=en-GB|access-date=2018-11-04}} For further examples of Cassini flybys of Saturn's moons see Timeline of Cassini-Huygens.

Cassini conducted many flybys at various distances of the moons of Saturn.{{Cite web|url=https://solarsystem.nasa.gov/news/13019/titan-flyby-t-126-final-close-encounter-gateway-to-the-grand-finale/|title = Titan Flyby T-126: Final Close Encounter, Gateway to the Grand Finale}} It achieved 126 flybys of Titan, and its final close flyby was on April 22, 2017 prior to its retirement.{{Cite web|url=https://solarsystem.nasa.gov/news/13019/titan-flyby-t-126-final-close-encounter-gateway-to-the-grand-finale|title=Titan Flyby T-126: Final Close Encounter, Gateway to the Grand Finale|website=Solar System Exploration: NASA Science|access-date=2019-01-03}}

An animation of the Cassini spacecraft trajectory around Saturn over 10 years, during which it passed closely by many moons of Saturn, is at right.

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{{further|List of minor planets and comets visited by spacecraft#List of comets visited by spacecraft}}

File:PIA13602-16epoxi.gif mission)]]

International Cometary Explorer (ISEE-3) passed through the plasma tail of comet Giacobini-Zinner doing a flyby of the distance of {{convert|7800|km|mi|abbr=on}} of the nucleus on September 11, 1985.{{Cite report |url=http://ipnpr.jpl.nasa.gov/progress_report/42-87/87X.PDF |title=Halley Comet Missions |publisher=NASA |first1=C. |last1=Stelzried |first2=L. |last2=Efron |first3=J. |last3=Ellis |pages=241–242 |date=July–September 1986 |id=TDA Progress Report 42-87}}

In 2010, the Deep Impact spacecraft, on the EPOXI mission did a flyby of comet Hartley 2.{{Cite magazine|url=https://www.wired.com/2010/11/epoxi-comet-flyby/|title=New Super Close-Up Images From Comet Flyby|last=Grossman|first=Lisa|date=2010-11-04|magazine=Wired|access-date=2019-01-01|issn=1059-1028}}

File:PIA21597 - New Radar Images of Asteroid 2014 JO25 (cropped).gif

Flyby is also sometimes loosely used to describe when, for example, an asteroid approaches and coasts by the Earth.{{Cite news|url=https://www.space.com/41761-asteroid-2018-rc-flyby-closer-than-moon-webcast.html|title=Two Small Asteroids Are Buzzing Earth This Weekend. See One Live Tonight!|work=Space.com|access-date=2018-11-04}}{{Cite news|url=https://www.cnet.com/news/asteroid-discovered-after-it-makes-the-closest-flyby-of-the-year/|title=Asteroid seen after it makes the closest flyby of the year|date=2018-08-13|work=CNET|access-date=2018-11-04|language=en}}

This was also the term for when a comet did a flyby of Mars in 2014.{{Cite news|url=https://www.space.com/38225-comet-siding-spring-mars-meteor-shower.html|title=Comet's 2014 Mars Flyby Caused Most Intense Meteor Shower Ever Recorded|work=Space.com|access-date=2018-11-04}}

P/2016 BA14 was radar imaged at distance of {{convert|2.2|e6mi|km}} from Earth in 2016, during its flyby.{{Cite news|url=https://www.space.com/32398-flyby-comet-was-way-bigger-than-thought.html|title=Flyby Comet Was WAY Bigger Than Thought|work=Space.com|access-date=2018-11-07}} This enabled the size of the nucleus to be calculated to about {{convert|1|km|ft|order=flip}} in diameter.{{Cite news|url=https://www.space.com/32398-flyby-comet-was-way-bigger-than-thought.html|title=Flyby Comet Was WAY Bigger Than Thought|work=Space.com|access-date=2018-11-07}}

On December 16, 2018 the short period comet 46P/Wirtanen had its closest approach of Earth, coming within {{convert|7.1|e6mi|abbr=off|disp=or}} (one of its closest approaches to Earth).{{Cite web|url=https://www.usatoday.com/story/news/nation/2018/12/04/comet-46-p-wirtanen-zoom-across-night-sky-next-week/2205179002/|title = Brightest comet of the year will zoom near Earth this week|website = USA Today}}

• Aerobraking
• Aerogravity assist
• Apsis
• Deliberate crash landings on extraterrestrial bodies ('fly-in')
• Flight dynamics (spacecraft)
• List of asteroid close approaches to Earth
• Orbital spaceflight
• Space rendezvous

{{Reflist}}

• [https://airandspace.si.edu/exhibitions/exploring-the-planets/online/tools/probes.cfm Smithsonian Air and Space- Probes and Fly-by Spacecraft]
• [https://web.archive.org/web/20161227213923/http://astronautix.com/l/lunarflyby.html Lunar flybys]

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Category:Spaceflight concepts