In an era where satellite observations of Earth are commonplace, it’s easy to forget that only a few decades ago, the amount of information available about the state of Earth’s environment was limited. Observations were infrequent, and data were sparsely located. The advent of the Geostationary Operational Environmental Satellites (GOES) marked a significant shift, providing continuous monitoring and revolutionizing weather forecasting.
As far back as the late 1950s, primitive numerical weather prediction models existed, capable of producing forecasts given a set of initial conditions. However, the data to provide those conditions were limited. For example, the weather balloon network in 1960 covered only about 10% of the troposphere and did not extend into the Southern Hemisphere, the tropics, or over the ocean. Forecasters relied on manual analysis of weather maps, cloud observations, and barometric pressure readings, often resulting in inaccurate forecasts beyond two days.
The introduction of geostationary observations was a game-changer. This approach allowed for continuous monitoring of the atmosphere over a particular region, leading to the development of NOAA’s GOES. Since 1975, these satellites have been pivotal in providing data for weather forecasting and environmental monitoring. The partnership between NOAA and NASA has advanced satellite observations, making GOES a sentinel in the sky for severe weather and environmental hazards.
GOES Heritage Missions: ATS and SMS
The heritage of GOES can be traced back to the Applications Technology Satellite (ATS) series, launched between 1966 and 1974. These missions explored new technologies for communications, meteorological, and navigation satellites. The ATS series tested the theory of gravity anchoring a satellite in a synchronous orbit, allowing it to remain stationary relative to Earth.
Although primarily testbeds, ATS satellites collected meteorological data and functioned as communications satellites. The inclusion of a spin-scan camera, developed by Verner Suomi and his team, allowed for clear visible photographs of Earth. This innovation led to new discoveries about storm origins, such as the development of the Fujita Scale for tornado intensity.
Following ATS, NASA and NOAA developed the Synchronous Meteorological Satellite (SMS) as an operational prototype for geosynchronous weather satellites. Launched in 1974, SMS satellites were the first designed to sense meteorological conditions in geostationary orbit. The Visible and Infrared Spin-Scan Radiometer (VISSR) became the workhorse instrument for these missions, providing high-quality day and night observations.
Generations of GOES: Evolution and Impact
First Generation: GOES 1-3
The GOES era began in October 1975 with the launch of GOES-1. The first three missions were spin-stabilized satellites, featuring the VISSR instrument for cloud and surface temperature observations. Early GOES missions provided crucial data about hurricanes, such as Tropical Storm Claudette and Hurricane David in 1979.
Second Generation: GOES 4-7
The second generation began in 1980 with GOES-4, introducing the VISSR Atmospheric Sounder (VAS) for temperature sounding capabilities. This allowed for more detailed tracking of storms, improving forecasts and enabling advanced warnings. GOES-7 added the capability of detecting distress signals, aiding in search and rescue operations.
Third Generation: GOES 8-12
In 1994, technological advances enabled significant improvements in GOES capabilities. The separation of the imager and sounder into distinct instruments allowed for more accurate forecasts. The third generation also introduced the Solar X-ray Imager (SXI) for monitoring solar storms.
Fourth Generation: GOES 13-15
By the mid-2000s, the fourth generation, known as the GOES-N series, enhanced mission capabilities with improved image navigation and registration. In 2011, GOES-13 monitored a record-breaking tornado outbreak, showcasing the satellite’s ability to provide critical real-time data.
The GOES-R Series: Advancements and Innovations
Launched in 2016, the GOES-R Series brought state-of-the-art instruments into orbit. The Advanced Baseline Imager (ABI) and the Geostationary Lightning Mapper provided unprecedented data for weather forecasting. These satellites offer minute-by-minute information, allowing for early warnings and improved monitoring of severe weather and environmental hazards.
The GOES-R Series also carries sophisticated solar imaging and space weather monitoring instruments. The final satellite, GOES-19, includes NOAA’s first compact coronagraph to detect coronal mass ejections, crucial for predicting space weather impacts on Earth.
Looking Ahead: GeoXO
NOAA, NASA, and industry partners are developing the next generation of geostationary satellites, GeoXO, to continue the GOES legacy. Scheduled for launch in the early 2030s, GeoXO will prioritize severe weather forecasting and environmental hazard monitoring, providing advanced capabilities well into the 2050s.
GeoXO aims to improve short-term forecasting and provide greater lead times for warnings, enhancing public safety and economic activity in the Western Hemisphere.
For 50 years, GOES satellites have provided continuous coverage of the Western Hemisphere, forming the backbone of short-term forecasts and warnings. Their data are essential for public safety, property protection, and efficient economic activity. As we look to the future, the legacy of GOES will continue to shape weather forecasting and environmental monitoring for decades to come.
Acknowledgment: The primary source for the information provided in the section on “GOES Heritage Missions” was Conway, Eric: Atmospheric Science at NASA: A History (2008), pp. 140-41.
Michelle Smith, NOAA Satellite and Information Service
