The Global-scale Observations of the Limb and Disk (GOLD) mission was launched by NASA on January 25, 2018, as a hosted payload aboard SES-14, a commercial communications satellite. This is the first NASA science mission to fly an instrument as a commercially hosted payload.

GOLD will investigate the dynamic interface between space and Earth’s uppermost atmosphere, with a focus on the influence of the ionosphere and thermosphere on each other. These regions respond both to space weather above, and the lower atmosphere below.

GOLD scans the entirety of the Earth’s disk every half hour.Hurricanes and other events in the lower atmosphere create waves that can travel up to this interface to space, changing wind patterns and causing disruptions. Above this region, flurries of energized particles and solar storms carry electric and magnetic fields and have the potential to disrupt Earth’s space environment. In addition to low-Earth orbiting satellites, the International Space Station t communication signals, like radio waves and signals that make our GPS systems work, also travel through this region, and sudden changes can distort them or even cut them off completely.

The data collected with a 30-minute cadence, much higher than any previous mission, will be used to improve forecasting models of the space weather events that can impact life on Earth, as well as satellites and astronauts in space. GOLD is the first mission that can provide observations fast enough to monitor the details of regular, hour-by-hour changes in space weather—not just its overarching climate.

The 80-pound GOLD instrument is an imaging spectrograph, measuring far ultraviolet light and creating full-disk ultraviolet images of Earth from its geostationary vantage point above the Western Hemisphere. The images will help produce the first maps of the upper atmosphere’s changing temperature and composition all over the Americas.