The Vegetation Canopy Lidar (VCL) is the first selected mission of the NASA Earth System Science Pathfinder (ESSP) program. The principal goal of the Vegetation Canopy Lidar is the characterization of the three-dimensional structure of the Earth through measurements of canopy vertical and horizontal structure and land surface topography. VCL is led by the University of Maryland, with collaboration from NASA's Goddard Space Flight Center (GSFC) Laboratory for Terrestrial Physics, and other academic and industrial contributors, including Orbital Sciences Corporation, Omitron, Inc, Swales Aerospace, Fibretek, Inc, Raytheon, and Universal Space Network.