Starting Feb. 11, 2000, NASA and the National Imagery and Mapping Agency – later renamed NGA – used a modified radar system onboard Space Shuttle Endeavour to acquire elevation data for over 80 percent of the Earth’s land mass. NIMA used this topographic data from the 11-day Shuttle Radar Topography Mission (SRTM) for multiple applications, from developing navigation tools and supporting military operations, to geological and environmental purposes. At the time, SRTM helped generate the most complete high-resolution digital topographic database on Earth.