Ball Aerospace & Technologies Corp. has delivered to NASA's Jet Propulsion Laboratory (JPL) key components for a laser ranging system designed to measure changes in Earth's oceans, groundwater and glaciers. The next generation of NASA's Gravity Recovery and Climate Experiment (GRACE) satellites, expected to launch in 2017, will use Ball's laser frequency stabilization reference flight units to take detailed measurements of Earth's gravity field during water investigations over land, ice and oceans. Developed under NASA's Instrument Incubator Program, the units constitute a subsystem of the Laser Ranging Interferometer, a secondary payload aboard the GRACE spacecraft. The next GRACE mission is expected to advance the state-of-the-art, proven technology . The current GRACE mission, launched in 2002, involves two identical spacecraft that fly about 137 miles apart in a polar orbit 310 miles above Earth. By using GPS and a microwave ranging system, GRACE maps Earth’s gravity field to yield crucial information about the distribution and flow of mass within the Earth and its surroundings. Gravity variations studied include changes due to surface and deep currents in the ocean, runoff and ground water storage on land masses, exchanges between ice sheets or glaciers and the ocean, and variations of mass within Earth. For more information, visit www.nasa.gov.