Lunar cycler near Earth - Artist view
author: Walter B. Myers/Novapix
reference: e-exl04-00002
Image Size 300 DPI: 33 * 25 cm
A lunar cycler rounds the south pole of the Earth near perigee--its closest approach to the Earth--while a trailing future generation space shuttle prepares for a rendezvous.
Once a lunar cycler has been propelled into its elliptical Earth/Moon orbit, it would require relatively little fuel over the ensuing years to maintain its orbit.
One thing to note about a lunar cycler is that while it does continually orbit between the Earth and Moon, it is not a tug, i.e., the cycler does not add any momentum to a docking space shuttle nor to any other craft that connects to it. Any ship that docks with the cycler must itself supply the initial energy required to reach an orbit matching the cycler's. What the cycler offers is a permanent transfer point for personnel and supplies and better accommodations for the weeklong journey to the Moon.