Editing Space rendezvous (section)

== History ==
In its first human spaceflight program [[Vostok programme|Vostok]], the [[Soviet Union]] launched pairs of spacecraft from the same launch pad, one or two days apart ([[Vostok 3|Vostok 3 and 4]] in 1962, and [[Vostok 5|Vostok 5 and 6]] in 1963). In each case, the [[launch vehicle]]s' guidance systems inserted the two craft into nearly identical orbits; however, this was not nearly precise enough to achieve rendezvous, as the Vostok lacked maneuvering thrusters to adjust its orbit to match that of its twin. The initial separation distances were in the range of {{convert|5|to|6.5|km|mi|sp=us}}, and slowly diverged to thousands of kilometers (over a thousand miles) over the course of the missions.<ref name=Gatland>{{Cite book
  | last = Gatland
  | first = Kenneth
  | title = Manned Spacecraft, Second Revision
  | publisher = Macmillan Publishing Co., Inc.
  | date = 1976
  | location = New York
  | pages = 117–118
  | isbn = 0-02-542820-9}}</ref><ref>{{cite book
 |title= The Rocket Men: Vostok & Voskhod, The First Soviet Manned Spaceflights
 |last= Hall
 |first= Rex
 |author2= David J. Shayler
 |date= 2001
 |publisher= [[Springer Science+Business Media|Springer–Praxis Books]]
 |pages= 185–191
 |location= New York
 |isbn= 1-85233-391-X
 |url= https://books.google.com/books?id=zndYLKa26wAC
 |access-date= September 25, 2016
 |archive-date= April 2, 2020
 |archive-url= https://web.archive.org/web/20200402223717/https://books.google.com/books?id=zndYLKa26wAC
 |url-status= live
 }}</ref>

In early 1964 the Soviet Union were able to guide two unmanned satellites designated [[Polyot (satellite)|Polyot 1 and Polyot 2]] within 5km, and the crafts were able to establish radio communication.<ref>{{Cite web |title=The Historic Beginnings Of The Space Arms Race |url=https://www.spacewar.com/reports/The_Historic_Beginnings_Of_The_Space_Arms_Race_999.html |access-date=2024-11-21 |website=www.spacewar.com}}</ref><ref>{{Cite web |last=RBTH |last2=Novosti |first2=Yury Zaitsev, RIA |date=2008-11-01 |title=The historic beginnings of the space arms race |url=https://www.rbth.com/articles/2008/11/01/311008_space.html |access-date=2024-11-21 |website=Russia Beyond |language=en-US}}</ref><ref>{{Cite web |title=MilsatMagazine |url=http://www.milsatmagazine.com/story.php?number=701833149 |access-date=2024-11-21 |website=www.milsatmagazine.com}}</ref>

In 1963 [[Buzz Aldrin]] submitted his doctoral thesis titled, '' Line-Of-Sight Guidance Techniques For Manned Orbital Rendezvous.''<ref name=buzz>{{cite web |title=Orbital Rendezvous |author=Buzz Aldrin |url=http://buzzaldrin.com/space-vision/rocket_science/orbital-rendezvous/ |access-date=May 4, 2012 |archive-date=October 9, 2011 |archive-url=https://web.archive.org/web/20111009142726/http://buzzaldrin.com/space-vision/rocket_science/orbital-rendezvous/ |url-status=live }}</ref> As a NASA astronaut, Aldrin worked to "translate complex [[orbital mechanics]] into relatively simple flight plans for my colleagues."<ref name=waterkeeper>{{cite web |title=From Earth to Moon to Earth |author=Buzz Aldrin |url=http://www.waterkeeper.org/wp-content/uploads/2013/08/Fall-2005-Hawks-Doves.pdf |url-status=dead |archive-url=https://web.archive.org/web/20140527224845/http://www.waterkeeper.org/wp-content/uploads/2013/08/Fall-2005-Hawks-Doves.pdf |archive-date=May 27, 2014 |df=mdy-all }}</ref>

===First attempt failed===

NASA's first attempt at rendezvous was made on June 3, 1965, when US astronaut [[Jim McDivitt]] tried to maneuver his [[Gemini 4]] craft to meet its spent [[Titan II GLV|Titan II launch vehicle]]'s upper stage. McDivitt was unable to get close enough to achieve station-keeping, due to depth-perception problems, and stage propellant venting which kept moving it around.<ref name="mcdivittoh">Oral History Transcript / [http://www.jsc.nasa.gov/history/oral_histories/McDivittJA/mcdivittja.pdf James A. McDivitt] {{Webarchive|url=https://web.archive.org/web/20160304130319/http://www.jsc.nasa.gov/history/oral_histories/McDivittJA/mcdivittja.pdf |date=March 4, 2016 }} / Interviewed by Doug Ward / Elk Lake, Michigan – June 29, 1999</ref>
However, the Gemini 4 attempts at rendezvous were unsuccessful largely because [[NASA]] engineers had yet to learn the [[orbital mechanics]] involved in the process. Simply pointing the active vehicle's nose at the target and thrusting was unsuccessful. If the target is ahead in the orbit and the tracking vehicle increases speed, its altitude also increases, actually moving it away from the target. The higher altitude then increases orbital period due to [[Kepler's laws of planetary motion#Third law|Kepler's third law]], putting the tracker not only above, but also behind the target. The proper technique requires changing the tracking vehicle's orbit to allow the rendezvous target to either catch up or be caught up with, and then at the correct moment changing to the same orbit as the target with no relative motion between the vehicles (for example, putting the tracker into a lower orbit, which has a shorter orbital period allowing it to catch up, then executing a [[Hohmann transfer orbit|Hohmann transfer]] back to the original orbital height).<ref name="gemini-4-ea">{{Cite web |url=http://www.astronautix.com/flights/gemini4.htm |title=Gemini 4 |publisher=Encyclopedia Astronautica |url-status=dead |archive-url=https://web.archive.org/web/20101129073633/http://astronautix.com/flights/gemini4.htm |archive-date=November 29, 2010 |df=mdy-all }}</ref>

{{quote|As [[Project Gemini|GPO]] engineer André Meyer later remarked, "There is a good explanation for what went wrong with rendezvous." The crew, like everyone else at [[Manned Spacecraft Center|MSC]], "just didn't understand or reason out the [[orbital mechanics]] involved. As a result, we all got a whole lot smarter and really perfected rendezvous maneuvers, which [[Apollo program|Apollo]] now uses."|<ref name="gemini-4-ea" />}}

===First successful rendezvous===
[[File:Gemini 7 in orbit - GPN-2006-000035.jpg|right|thumb|Gemini 7 photographed from Gemini 6 in 1965]]
Rendezvous was first successfully accomplished by US astronaut [[Wally Schirra]] on December 15, 1965. Schirra maneuvered the [[Gemini 6A|Gemini 6]] spacecraft within {{convert|1|ft|cm}} of its sister craft [[Gemini 7]]. The spacecraft were not equipped to dock with each other, but maintained station-keeping for more than 20 minutes. Schirra later commented:<ref>{{cite web|url=http://www.hq.nasa.gov/office/pao/History/SP-4203/ch12-7.htm|title=On The Shoulders of Titans - Ch12-7|website=www.hq.nasa.gov|access-date=April 9, 2018|archive-date=April 3, 2020|archive-url=https://web.archive.org/web/20200403013722/http://www.hq.nasa.gov/office/pao/History/SP-4203/ch12-7.htm|url-status=live}}</ref>

{{quote|Somebody said ... when you come to within three miles (5 km), you've rendezvoused. If anybody thinks they've pulled a rendezvous off at three miles (5 km), have fun! This is when we started doing our work. I don't think rendezvous is over until you are stopped – completely stopped – with no relative motion between the two vehicles, at a range of approximately {{convert|120|ft|m}}. That's rendezvous! From there on, it's stationkeeping. That's when you can go back and play the game of driving a car or driving an airplane or pushing a skateboard – it's about that simple.}}

Schirra used another metaphor to describe the difference between the two nations' achievements:<ref name="agle199809">{{Cite magazine |last=Agle |first=D.C. |date=September 1998 |title=Flying the Gusmobile |url=https://www.airspacemag.com/flight-today/flying-the-gusmobile-218187/ |magazine=Air & Space |language=en |access-date=2018-12-15 |archive-date=April 3, 2020 |archive-url=https://web.archive.org/web/20200403013717/https://www.airspacemag.com/flight-today/flying-the-gusmobile-218187/ |url-status=live }}</ref>

{{quote|[The Russian "rendezvous"] was a passing glance—the equivalent of a male walking down a busy main street with plenty of traffic whizzing by and he spots a cute girl walking on the other side. He's going 'Hey wait' but she's gone. That's a passing glance, not a rendezvous.}}

===First docking===
{{More citations needed|section|date=August 2020}}
{{Main|Docking and berthing of spacecraft}}
[[File:S66-25781 PR.jpg|thumb|Gemini 8 Agena target vehicle]]
[[File:Gemini8Docking.gif|thumb|Gemini 8 docking with Agena vehicle]]

The first docking of two spacecraft was achieved on March 16, 1966 when [[Gemini 8]], under the command of [[Neil Armstrong]], rendezvoused and docked with an uncrewed [[Agena Target Vehicle]]. Gemini 6 was to have been the first docking mission, but had to be cancelled when that mission's Agena vehicle was destroyed during launch.<ref>{{cite web|url=http://nssdc.gsfc.nasa.gov/nmc/spacecraftDisplay.do?id=GEM|title=NASA - NSSDCA - Spacecraft - Details|website=nssdc.gsfc.nasa.gov|access-date=April 9, 2018|archive-date=April 3, 2020|archive-url=https://web.archive.org/web/20200403231734/https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=GEM|url-status=live}}</ref>

The Soviets carried out the first automated, uncrewed docking between [[Cosmos 186]] and [[Cosmos 188]] on October 30, 1967.<ref>[https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1967-105A NSSDC ID: 1967-105A] {{Webarchive|url=https://web.archive.org/web/20200413185438/https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1967-105A |date=April 13, 2020 }} NASA, NSSDC Master Catalog</ref>

The first Soviet cosmonaut to attempt a manual docking was [[Georgy Beregovoy]] who unsuccessfully tried to dock his [[Soyuz 3]] craft with the uncrewed [[Soyuz 2]] in October 1968. Automated systems brought the craft to within {{convert|200|m|ft|sp=us}}, while Beregovoy brought this closer with manual control.<ref>{{Cite web |title=Part 1 - Soyuz |url=https://historycollection.jsc.nasa.gov/history/shuttle-mir/references/documents/mirhh-part1.pdf |url-status=live |archive-url=https://web.archive.org/web/20221007084620/https://historycollection.jsc.nasa.gov/history/shuttle-mir/references/documents/mirhh-part1.pdf |archive-date=2022-10-07 |website=History Collection - Johnson Space Center - NASA |page=11}}</ref>

The first successful crewed docking<ref name="MAAS Collection">{{cite web | title=Model of a Soyuz-4-5 spacecraft | website=MAAS Collection | url=https://collection.maas.museum/object/157010 | access-date=Oct 22, 2021}}</ref> occurred on January 16, 1969 when [[Soyuz 4]] and [[Soyuz 5]] docked, collecting the two crew members of Soyuz 5, which had to perform an [[extravehicular activity]] to reach Soyuz 4.<ref name="NASA">{{cite web | title=NSSDCA - Spacecraft - Details | website=NASA | url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1969-004A | language=no | access-date=Oct 22, 2021}}</ref>

In March 1969 [[Apollo 9]] achieved the first internal transfer of crew members between two docked spacecraft.

The first rendezvous of two spacecraft from different countries took place in 1975, when an Apollo spacecraft docked with a Soyuz spacecraft as part of the [[Apollo–Soyuz]] mission.<ref>{{cite encyclopedia|url=https://books.google.com/books?id=K751AwAAQBAJ&pg=PT747|title=Encyclopedia of United States National Security|isbn=978-0-7619-2927-7|publisher=[[SAGE Publications]]|editor-first=Richard J.|editor-last=Samuels|editor-link=Richard J. Samuels|edition=1st|date=December 21, 2005|page=669|quote=Most observers felt that the U.S. moon landing ended the space race with a decisive American victory. […] The formal end of the space race occurred with the 1975 joint Apollo–Soyuz mission, in which U.S. and Soviet spacecraft docked, or joined, in orbit while their crews visited one another's craft and performed joint scientific experiments.|access-date=September 20, 2020|archive-date=July 26, 2020|archive-url=https://web.archive.org/web/20200726071509/https://books.google.com/books?id=K751AwAAQBAJ&pg=PT747|url-status=live}}</ref>

The first multiple space docking took place when both [[Soyuz 26]] and [[Soyuz 27]] were docked to the [[Salyut 6]] space station during January 1978.{{citation needed|date=December 2011}}