NASA Logo, National Aeronautics and Space Administration
NASA Space Science Data Coordinated Archive Header

Laser Ranging Retroreflector

NSSDCA ID: 1971-063C-08

Mission Name: Apollo 15 Lunar Module /ALSEP
Principal Investigator:Dr. James E. Faller


The Laser Ranging Retroreflector Experiment (LRRR), part of the ALSEP package, was a corner reflector for laser ranging from earth. The ranging data obtained included information on lunar motion, lunar librations, and earth rotation. The LRRR experiment consisted of a folded panel structure incorporating 300 individual fused-silica optical corner reflectors, a simple alignment/leveling device, and an aim-handle mechanism. The Lunar Roving Vehicle (LRV) was used to carry the LRRR to the Hadley rill site. The LRRR became passive after deployment. A camera (60-mm lens) was used to photograph the experiment. The LRRR could be used indefinitely and provided data that, when used in conjunction with data from the Apollo 11 and 14 LRRR experiments, permited more refined distance measurements than were previously available. Now that smaller telescopes can be used, the experiment is providing greater quantities of more accurate data.

Alternate Names

  • Apollo15ALSEP/LaserRangingRetroreflector
  • Laser Ranging Retro-Reflector
  • S078

Funding Agency

  • NASA-Office of Space and Terrestrial Applications (United States)


  • Earth Science: Geophysics/Geodesy
  • Planetary Science: Celestial Mechanics

Additional Information

Questions and comments about this experiment can be directed to: Coordinated Request and User Support Office



NameRoleOriginal AffiliationE-mail
Dr. James E. FallerPrincipal InvestigatorUniversity of

Related Information

Lunar Ranging at McDonald Observatory

Lunar Ranging at McDonald Observatory

McDonald Laser Ranging Station (University of Texas)
Current Lunar Laser Ranging Data Sets

[] NASA Logo -