An anonymous reader quotes a report from Ars Technica: A new NASA mission, the first to hitch a ride on a commercial communications satellite, will examine Earth's upper atmosphere to see how the boundary between Earth and space changes over time. GOLD stands for Global-scale Observations of the Limb and Disk, and the mission will focus on the temperature and makeup of Earth's highest atmospheric layers. Along with another upcoming satellite, called ICON, GOLD will examine how weather on Earth -- and space weather caused by the sun -- affects those uppermost layers. GOLD, which will inspect the ultraviolet radiation that the upper atmosphere releases, will also be the first to take comprehensive records of that atmospheric layer's temperature. The satellite carrying GOLD will orbit 22,000 miles (35,400 kilometers) above Earth in a geostationary orbit, which means GOLD will stay fixed with respect to Earth's surface as the satellite orbits and the world turns. GOLD will pay particularly close attention to Earth's thermosphere, which is the gas that surrounds the Earth higher than 60 miles (97 km) up, and the layer called the ionosphere, which forms as radiation from the sun strips away electrons from particles to create charged ions. And although solar flares and other interactions on the sun do have a strong impact on those layers, scientists are learning that Earth's own weather has an impact on the layers, too.