The National Oceanic and Atmospheric Administration’s (NOAA) GOES series of geostationary weather satellites has been a backbone of short-term forecasting in the United States since the late 1970s. The GOES satellites circle in a geosynchronous orbit, hovering about 35,800 km above Earth’s surface and continuously monitoring the same region on its face. They gather information about thunderstorms, blizzards, tropical storms and hurricanes, volcanic ash eruptions and other severe weather events. The real-time data collected by GOES, in combination with Doppler radars and automated surface observing systems, is disseminated to NOAA’s National Weather Service meteorologists and used to warn people of hazardous conditions.

With the exception of a few months in the 1990s, GOES satellites have been active and operating continuously ever since, offering a constant stream of important weather-related information. The GOES-East satellite, located at 75° West longitude, provides primary coverage over North America, while the GOES-West spacecraft, located at 135° West longitude, covers most of the Atlantic and Pacific. The main mission of each operational GOES satellite is carried out by the primary instruments, the Imager and the Sounder. The Imager detects reflected solar energy in the visible and infrared spectrum to measure atmospheric temperature, moisture, cloud top and surface temperatures, and ozone distribution. The Sounder is a 19-channel radiometer that senses emitted thermal energy and reflected solar energy to calculate vertical atmospheric temperature and moisture profiles.

In addition to the Imager and Sounder, GOES satellites carry an array of secondary instruments that perform important functions. The most important secondary instruments are the Geostationary Lightning Mapper (GLM) and the Enhanced Visible and Infrared Imager for Severe Thunderstorms (EVS). The GLM and EVS are critical to NOAA’s National Weather Service meteorologists at local forecast offices, national centers, and volcano observatories in their efforts to warn the public of potentially hazardous weather. GOES satellites also support the NOAA Search and Rescue Satellite (S&RSAT) system by relaying distress signals transmitted in the UHF frequency band to rescuers on Earth and at sea.

The GOES program has evolved and grown with new advancements and innovations since the first spacecraft, GOES-1, was launched in 1975. The GOES program is a collaboration between NOAA and NASA, with NOAA providing funding, requirements and operations of the system in orbit. NASA, under contract to NOAA, is responsible for procurement, design and development of the satellites, the spacecraft, and their sensors; and launch services.

The current GOES-R series of satellites, currently in operation at GOES-M and GOES-U, feature the GOES-R Sounder and Enhanced Visible and Infrared Satellite Imager (EVS). The next generation GOES U satellite will debut the Naval Research Laboratory’s Compact Coronagraph (CCOR) instrument to monitor dangerous space weather phenomena such as coronal mass ejections that could impact astronauts and other orbiting objects.

The Aerospace Corporation supports the GOES program across a broad range of activities and milestones, including supporting the NASA-led effort to develop CCOR for the upcoming GOES-U satellite, which will be launched in 2024. The CCOR instrument will provide operators with the first-ever ability to monitor dangerous space weather conditions that can adversely affect Earth and space assets.