Since its launch on October 16, 1975, the geostationary weather satellite GOES (Global Observing System) has become an essential component of National Weather Service operations. Its sensors continuously monitor the atmosphere for important atmospheric “triggers” that can produce tornadoes, flash floods, hail storms and hurricanes. GOES satellites have instruments that can detect and observe both Earth-emitted and reflected radiation, from which atmospheric temperature, winds, moisture and cloud cover can be derived. The newest generation, GOES-8 and GOES-9, have instruments that can also detect and observe the Sun’s radiation, allowing NOAA forecasters to warn of potentially hazardous solar activity that could affect space and ground-based assets.

The GOES series of satellites are a joint NOAA/NASA program. NOAA provides funding, requirements and mission operation, NASA designs and builds the spacecraft, and the instruments, and launches each satellite into orbit. Once the GOES satellites are in geostationary orbit and have completed their on-orbit checkout, NOAA’s Satellite Operation Control Center at Suitland, Maryland, takes command and control of the system. NOAA’s NESDIS (National Environmental Satellite, Data and Information Services Division) is responsible for satellite monitoring and data receipt and for product generation and distribution.

In its day, GOES-1 gave meteorologists their first near-real time look at atmospheric conditions from a fixed position. The satellite used a spin-stabilized Visible/Infrared Spin-Scan Radiometer to provide day and night images of the surface, clouds and cloud heights. GOES-2 to GOES-9 added a variety of other sensors, including a Spectral Radiance Meter for the measurement of the Earth’s brightness, a Sounder for vertical atmospheric temperature and moisture profiles, and the Space Environment In-Situ Suite (SEISS) instrument package.

GOES-12 and -13 introduced the Solar X-Ray Imager (SXI), an instrument that gives the NWS real-time imagery of solar flares and sunspots, allowing them to issue warnings before the solar radiation could harm space-borne and ground-based assets. The next satellite in the GOES-R series will feature this same capability, as well as the Advanced Baseline Imager and Extreme Ultraviolet and X-ray Irradiance Sensor.

The GOES-T satellite, which will provide western North America coverage, is being launched today by United Launch Alliance (ULA) using its heritage Atlas and Delta launch vehicles. ULA’s track record of launching every GOES-series satellite that has ever been launched dates back to the first GOES-A launch in 1975, which was mounted on a Delta rocket.