The Smithsonian Astrophysical Observatory (SAO) and the Centre National d’Études Spatiales (CNES): contributions to the international laser ranging network

The Smithsonian Astrophysical Observatory (SAO) and the Centre National d’Études Spatiales (CNES) worked closelytogether in the early years of the space program to deploy satellite laser ranging (SLR) systems at overseas sites to enhance
global coverage to support specific missions. The data were routinely made available for use by the science community for programs in geodesy, gravity field, atmospheric physics, and ultimately for oceanography and geodynamics. SAO and CNES
organized campaigns for international participation and loaned each other equipment to enhance the network. SAO and CNES provided technical expertise and advice to a number of other groups as they planned and deployed SLR systems. In this paper,
we will discuss the history and the role of the two institutions in the building of the international SLR network.