Since its first successful demonstration in 1964, the precision of Satellite Laser Ranging (SLR) has improved by three orders of magnitude, i.e., from a few meters to a few mm. Each technological improvement has been rapidly followed by a new scientific capability. To date, centimeter accuracy SLR measurements to the passive LAGEOS satellites by a ground-based network of approximately 40 stations have; (1) helped to define a Terrestrial Reference Frame accurate to a centimeter globally; (2) measured the motions of tectonic plates and detected regional crustal deformations near the plate boundaries; (3) helped define the terrestrial gravity field; and (4) monitored variations in the Earth's gravity field, the orientation of the Earth's spin axis, and its rate of rotation and related them to angular momentum exchanges and/or large mass redistribution within the land, ocean, atmosphere system. By providing few centimeter precision orbits measurement to altimetric satellites such as ERS-1 and 2 and TOPEX/POSEIDON, SLR has enabled precise measurements of global ocean, circulation, wave heights, ice topography, and even mean sea level rises on the order to two mm/yr. In addition to providing useful test of general relativity, centimeter accuracy SLR measurements to five retroreflector packages placed on the lunar surface by US and Soviet landers have helped to define the planetary reference frame, provided ultraprecise lunar ephemerides, defined the lunar librations, and constrained models of the Moon's internal structure.