Astronaut and Lunar Module pilot Buzz Aldrin is pictured during the Apollo 11 extravehicular activity on the moon. He had just deployed the Early Apollo Scientific Experiments Package. In the foreground is the Passive Seismic Experiment Package; beyond it is the Laser Ranging Retro-Reflector (LR-3). In the left background is the black and white lunar surface television camera and in the far right background is the Lunar Module “Eagle.” Mission commander Neil Armstrong took this photograph with the 70mm lunar surface camera.
The LR-3 experiment has produced many important measurements that have improved our knowledge of changes of the Earth’s rotation and have been used to test Einstein’s Theory of Relativity. The LR-3, which consists of a series of corner-cube reflectors composed of a special type of mirror that always reflecting an incoming light beam back in the direction from which it came, is the only Apollo experiment that is still returning data from the moon.
Apollo 11 landed on the lunar surface 38 years ago today on July 20, 1969.
Image credit: NASA