Long-range tests of the equivalence principle

The equivalence principle can be tested using accurate tracking of the Moon , planets, and interplanetary spacecraft. Tests with solar system bodies pr obe the dependence of the equivalence principle on self-energy. Analysis of lunar laser ranges yields the difference in the ratio of the gravitational and inertial masses for the Earth and Moon of (-0.7 +/- 1.5) x 10(-13). In conjunction with laboratory tests of the equivalence principle and spacecr aft and VLBI tests of PPN gamma, one derives /beta - 1/ less than or equal to 0.0005. Planetary tests are feasible, in particular tests using Mars. Im provements in Doppler accuracies under development may allow tests with int erplanetary spacecraft.