World Library  
Flag as Inappropriate
Email this Article

Circumlunar trajectory

Article Id: WHEBN0023448451
Reproduction Date:

Title: Circumlunar trajectory  
Author: World Heritage Encyclopedia
Language: English
Subject: Free return trajectory, Exploration Mission 1, Space Launch System, Apollo program, Orion (spacecraft)
Collection:
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Circumlunar trajectory

The trajectory followed by Apollo 13
Sketch of a circumlunar free return trajectory (not to scale).

A circumlunar trajectory, trans-lunar trajectory or lunar free return is a type of free return trajectory which takes a spacecraft from Earth, around the far side of the Moon, and back to Earth using only gravity once the initial trajectory is set.

Background

The first spacecraft to fly a circumlunar trajectory was Luna 3. Circumlunar trajectories were also used by Apollo missions prior to lunar orbit insertion,[1] to provide a free return to Earth in the event of a propulsion system malfunction on the way to the Moon. This was used on Apollo 13, when an oxygen tank rupture necessitated return to Earth without firing the Service Module engine, although a number of course corrections using the Lunar Module descent engine were required to maintain this trajectory.[2]

A number of manned missions were also proposed to intentionally conduct circumlunar flybys, including the Soviet Soyuz 7K-L1 or Zond programme, and several US proposals, including Gemini-Centaur and an early Apollo proposal.[3]

See also

References

  1. ^ "The launch and mission trajectory". Apollo 13 Mission Report. Spaceflight Now. Retrieved 2009-06-30. 
  2. ^ Turnhill, Reginald. "Apollo 13 on Free Return Trajectory". Spaceflight Now. Retrieved 2009-06-30. 
  3. ^ Wade, Mark. "Manned Circumlunar". Encyclopedia Astronautica. Retrieved 2009-06-30. 



This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.