The Apache Point Observatory Lunar Laser-ranging Operation, or APOLLO, is a project at the Apache Point Observatory in New Mexico. It is an extension and advancement of the Lunar Laser Ranging Experiment, which uses retroreflectors on the Moon to track changes in lunar orbital distance and motion.

External Links

• http://science.nasa.gov/headlines/y2004/21jul_llr.htm?list736830
• http://physics.ucsd.edu/%7Etmurphy/apollo/apollo.html