The location at a lunar base of an additional laser ranging retroreflector package and a tracking becon would result in increased ranging accuracy through augmentation of the data rate and for more uniform coverage through the lunar cycle. However, an even more attractive approach would be to place a combination of small microwave and optical transponders on the moon. This could improve the lunar ranging accuracy by nearly two orders of magnitude and also simplify the measurements.The K‐band microwave transponders would be operated at the lunar base and at two remote sites to permit much improved lunar libation and tidal displacement measurements. When simultaneous measurements to the three transponders are made from an observatory on the Earth, the range errors due to the uncertainties in the tropospheric and ionospheric propagation corrections will be the same to roughly 1%, and thus will nearly cancel out in the libration and tide measurements. A two‐wavelength laser transponder also would be operated at the lunar base so that accurate tropospheric propagation corrections can be made. This would make possible major improvements in measurements of the lunar orbit and of the Earth’s rotation, as well as in tests of general relativity.