The Geostationary Operational Environmental Satellite (GOES) program is a key element in United States National Weather Service (NWS) operations. GOES weather imagery and quantitative sounding data are a continuous and reliable stream of environmental information used to support weather forecasting, severe storm tracking , and meteorological research . Evolutionary improvements in the geostationary satellite system since 1974 (i.e., since the first Synchronous Meteorological Satellite , SMS-1) have been responsible for making the current GOES system the basic element for U.S. weather monitoring and forecasting. Spacecraft and ground-based systems work together to accomplish the GOES mission.

The United States has three in operation.

• GOES-9 is on loan to Japan over the mid Pacific as part of a multinational agreement since the Japanese satellite GMS-5 reached the end of its life and the failed launch of the replacement satellite MTSAT-1.
• GOES-10 is GOES-West over the eastern Pacific Ocean.
• GOES-12 is designated GOES-East, over the Amazon River and provides most of the U.S. weather information.

GOES-12 visible light image.

GOES-12 water vapor image.

Designed to operate in geostationary orbit, 35,790 km (22,240 statute miles) above the earth, thereby remaining stationary (with respect to a point on the ground), the advanced GOES I–M spacecraft continuously view the continental United States, neighboring environs of the Pacific and Atlantic Oceans, and Central and South America. The three-axis, body-stabilized spacecraft design enables the sensors to "stare" at the earth and thus more frequently image clouds, monitor earth's surface temperature and water vapor fields , and sound the atmosphere for its vertical thermal and vapor structures. Thus the evolution of atmospheric phenomena can be followed, ensuring real-time coverage of short-lived dynamic events, especially severe local storms and tropical cyclones—two meteorological events that directly affect public safety, protection of property, and ultimately, economic health and development. The importance of this capability has recently been exemplified during hurricanes Hugo (1989) and Andrew (1992).

The GOES I–M series of spacecraft are the principal observational platforms for covering such dynamic weather events and the near-earth space environment for the 1990s and into the 21st century. These advanced spacecraft enhance the capability of the GOES system to continuously observe and measure meteorological phenomena in real time, providing the meteorological community and the atmospheric scientist greatly improved observational and measurement data of the Western Hemisphere. In addition to short-term weather forecasting and space environmental monitoring, these enhanced operational services also improve support for atmospheric science research, numerical weather prediction models , and environmental sensor design and development.

The main mission is carried out by the primary payload instruments, the Imager and the Sounder. The Imager is a multichannel instrument that senses radiant energy and reflected solar energy from the earth's surface and atmosphere. The Sounder provides data for vertical atmospheric temperature and moisture profiles , surface and cloud top temperature, and ozone distribution.

Other instruments on board the spacecraft are the ground-based meteorological platform data collection and relay, and the space environment monitor. The latter consists of a magnetometer, an X-ray sensor, a high energy proton and alpha detector, and an energetic particles sensor, all used for in-situ surveying of the near-earth space environment.

Invertible GOES logo designed for Space Systems/Loral by Scott Kim

In addition, the GOES satellites carry ELT and EPIRB receivers, which are used for search-and-rescue purposes by the U.S. Air Force Rescue Coordination Center

GOES spacecraft have been manufactured by Boeing (GOES-D through -H and N–Q) and Space Systems/Loral (A–C, I–M). The procurement, design and manufacturing of GOES is overseen by NASA, while all operations of the satellites once in orbit are done by NOAA. Twelve contracts for advanced architecture studies for GOES-R were announced in October 2003.

Once a GOES satellite is launched successfully, it is redesignated with a number. GOES-A to GOES-F became GOES-1 to GOES-6, GOES-G was a failure, GOES-H to GOES-M became GOES-7 to GOES-12, the rest have not yet been launched.

Note: original entry taken from "GOES I–M Databook" foreword

See also

• remote sensing
• MTSAT , Japanese weather satellite program