Lunar orbit

For the orbit of the Moon around the Earth, see Orbit of the Moon.
Orion capsule of Artemis 1 above the Moon in December 2022.

In astronomy and spaceflight, a lunar orbit (also known as a selenocentric orbit) is an orbit by an object around Earth's Moon. In general these orbits are not circular. When farthest from the Moon (at apoapsis) a spacecraft is said to be at apolune, apocynthion, or aposelene. When closest to the Moon (at periapsis) it is said to be at perilune, pericynthion, or periselene. These derive from names or epithets of the moon goddess.

Lunar orbit insertion (LOI) is an orbit insertion maneuver used to achieve lunar orbit.[1]

Low lunar orbit (LLO) is an orbit below 100 km (62 mi) altitude. These have a period of about 2 hours.[2] They are of particular interest in the exploration of the Moon, but suffer from gravitational perturbations that make most unstable, and leave only a few orbital trajectories possible for indefinite frozen orbits. These would be useful for long-term stays in LLO.[2]

  1. ^ Woods, W.D. (2008). "Entering lunar orbit: the LOI manoeuvre". How Apollo Flew to the Moon. Space Exploration. Springer Praxis Books. pp. 189–210. doi:10.1007/978-0-387-74066-9_8. ISBN 978-0-387-71675-6.
  2. ^ a b Cite error: The named reference nasa20061106 was invoked but never defined (see the help page).