A NASA system, sponsored by its Office of Space Science, that maintains archives of images from its lunar and planetary missions, astronomical observations, and laboratory measurements. PDS also distributes the images to scientists and the public to ensure their long-term use and to stimulate advanced research. The system operates Regional Planetary Imaging Data Facilities (RPIF) at more than a dozen sites around the USA and in other nations. Each has a complete library of images that can be viewed by appointment, selected, and ordered.