Editing Earth orbit rendezvous (section)

{{short description|Method for conducting round trip human flights to the Moon}}
[[File:Gemini 6 7.jpg|thumb|200px|[[Gemini 7]] as seen from [[Gemini 6]] during their rendezvous in Earth orbit in 1965 (NASA)]]
'''Earth orbit rendezvous''' ('''EOR''') is a method for conducting round trip human flights to the Moon, involving the use of [[space rendezvous]] to assemble, and possibly fuel, components of a translunar vehicle in [[low Earth orbit]].<ref>"LOW EARTH ORBIT RENDEZVOUS STRATEGY FOR LUNAR MISSIONS" http://www.informs-sim.org/wsc06papers/158.pdf</ref> It was considered as an alternative to direct ascent but ultimately rejected in favor of [[lunar orbit rendezvous]] (LOR) for [[NASA]]'s [[Apollo program]] of the 1960s and 1970s,<ref>{{Cite book |last=Launius |first=Roger D. |url=http://www.jstor.org/stable/j.ctvhrcxzx |title=Reaching for the Moon: A Short History of the Space Race |date=2019-06-25 |publisher=Yale University Press |isbn=978-0-300-24516-5 |doi=10.2307/j.ctvhrcxzx|jstor=j.ctvhrcxzx }}</ref> mainly because LOR does not require a spacecraft big enough to both make the return trip from Earth orbit to splash down in the ocean and a soft landing on the lunar surface.<ref>"Lunar Orbit Rendezvous and the Apollo Program" http://www.nasa.gov/centers/langley/news/factsheets/Rendezvous.html {{Webarchive|url=https://web.archive.org/web/20130406180052/http://www.nasa.gov/centers/langley/news/factsheets/Rendezvous.html |date=2013-04-06 }}</ref> The two main proposed methodologies were: the in-space assembly of fueled spacecraft modules via docking techniques; and the in-space refueling of fully assembled spacecraft.<ref>{{Cite journal |last=Holmes |first=Brainerd |date=October 1962 |title=Manned Space Flight |journal=[[AIBS Bulletin]] |publisher=[[Oxford University Press]] |volume=12 |issue=5 |pages=56–9 |doi=10.2307/1293010|jstor=1293010 }}</ref> This was the preferred approach adopted by the Soviet Union for achieving human lunar missions.<ref>{{Cite news |last=Simons |first=Howard |date=March 28, 1965 |title=Historic Flight Prove Moon Race Is On |work=[[The Miami Herald]]}}</ref>

Three decades later, it was planned to be used for [[Project Constellation]], until that program's [[Barack Obama space policy speech at Kennedy Space Center|cancellation in October 2010]].<ref>Connolly, John F. (October 2006). "Constellation Program Overview" http://www.nasa.gov/pdf/163092main_constellation_program_overview.pdf {{Webarchive|url=https://web.archive.org/web/20070710060512/http://www.nasa.gov/pdf/163092main_constellation_program_overview.pdf |date=2007-07-10 }}</ref>