This collection of radiation budget, cloud, aerosol, and tropospheric data from the Langley Research Center of the National Aeronautics and Space Administration (NASA) contains recent and archival data sets. The data are free, but users must register and log in for access. Downloads from the NASA Water Vapor Project, the Clouds and Earth's Radiant Energy System (CERES) Pathfinder, and the Airborne Multi-angle Imaging SpectroRadiometer (AirMISR) are among the offerings (Java, HTML, FTP). The site also features pages on software, Langley Center activities, news, and a FAQ page.