Astronomy:Earth orbit rendezvous

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.[1] 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,[2] 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.[3] 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.[4] American in 1965 believed that this was the preferred approach adopted by the Soviet Union for achieving human lunar missions.[5]
Three decades later, it was planned to be used for Project Constellation, until that program's cancellation in October 2010.[6]
Gemini and Agena target vehicle
The Agena target vehicle (ATV) was used for testing Earth orbit rendezvous in the NASA Gemini Program. Gemini 6 and Gemini 7 rendezvoused in orbit in 1965, but without Agena. Next, Gemini 8 successfully docked with the Agena on March 16, 1966. The Agena-Gemini rendezvous also achieved other objectives in later Gemini launches, including docked orbital maneuvering (Gemini 10 and Gemini 11), inspection of the abandoned Gemini 8 ATV (Gemini 10) and space walks (Gemini 12).[7]
Apollo

In the end, NASA employed the Lunar Orbit Rendezvous for the Apollo Program: a Saturn V would simultaneously lift both the Apollo Command and Lunar Modules into low Earth orbit, and then the Saturn V third stage would fire again (Trans-lunar injection) to send both spacecraft to the Moon.[8]
Constellation
References
- ↑ "LOW EARTH ORBIT RENDEZVOUS STRATEGY FOR LUNAR MISSIONS" http://www.informs-sim.org/wsc06papers/158.pdf
- ↑ Launius, Roger D. (2019-06-25). Reaching for the Moon: A Short History of the Space Race. Yale University Press. doi:10.2307/j.ctvhrcxzx. ISBN 978-0-300-24516-5. http://www.jstor.org/stable/j.ctvhrcxzx.
- ↑ "Lunar Orbit Rendezvous and the Apollo Program" http://www.nasa.gov/centers/langley/news/factsheets/Rendezvous.html
- ↑ Holmes, Brainerd (October 1962). "Manned Space Flight". AIBS Bulletin (Oxford University Press) 12 (5): 56–9. doi:10.2307/1293010.
- ↑ Simons, Howard (March 28, 1965). "Historic Flight Prove Moon Race Is On". The Miami Herald.
- ↑ Connolly, John F. (October 2006). "Constellation Program Overview" http://www.nasa.gov/pdf/163092main_constellation_program_overview.pdf
- ↑ Sparrow, Giles (2007). Spaceflight : the complete story from Sputnik to shuttle -- and beyond. London: Dorling Kindersley. pp. 110. ISBN 9781405318181. OCLC 124970031.
- ↑ "Chariots for Apollo: A History of Manned Lunar Spacecraft". NASA. 1979. Archived from the original on 2004-11-18. https://web.archive.org/web/20041118232618/https://history.nasa.gov/SP-4205/ch3-2.html. Retrieved 2007-04-27.
