Europe’s Meteorological Operational (Metop) satellite series showcases a history of close collaboration between the continent and the United States to monitor weather, climate and Earth’s atmosphere. Two of the satellites in the Metop series are expected to remain in service through 2027 and 2030, operated by the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), the European Space Agency (ESA) and other international partners.
They are among some 47,500 objects in space — active payloads, unspecified objects and debris — monitored by the U.S. Space Force at space-track.org.
EUMETSAT splits global coverage with the U.S. National Oceanic and Atmospheric Administration (NOAA). Metop-B and Metop-C provide what’s known as morning orbit service and NOAA the afternoon service through its series of Polar Operational Environmental Satellites. The two series of satellites operate in low Earth orbit at about 840 kilometers, circling the planet from polar region to polar region — in the case of Metop, every 100 minutes or so. They complement weather satellites — including EUMETSAT’s Meteosat family — that are always trained on the same region of Earth and operate in geostationary orbit high above the equator. Metop-A, first in its series, launched in 2006 and was deorbited in 2021.
Meteosat satellites, at 36,000 kilometers up, can monitor rapidly evolving events for real-time and short-term weather prediction, but they can’t see the poles or the opposite hemisphere. The three Metop satellites have helped fill the gap, making more detailed observations along their paths. All three are identical in design, about the size of a small bus at 4,000 kilograms and each carrying 11 instruments to monitor temperature, humidity, trace gases, ozone and other metrics. These instruments include an infrared atmospheric sounding interferometer, measuring infrared radiation emitted from Earth’s surface for data on humidity and temperature in the troposphere — the lowest layer of Earth’s atmosphere, where most weather occurs — and in the lower stratosphere.
Origins
For a quarter of a century, under a 1998 agreement with EUMETSAT, NOAA provided both morning and afternoon coverage to Europe — some of it using instruments developed on the continent. Now, the EUMETSAT Polar System (EPS), including the Metop satellites, comprises the European component of the Europe-U.S. Joint Polar System. Through this system, EUMETSAT and NOAA exchange data, instruments and operational services. The Meteosat program began in the 1970s. In 1995, EUMETSAT took over the operation of Meteosat satellites from the ESA.
Today, EUMETSAT consists of 30 member states. Other meteorological interests in Europe include the European Meteorological Network, the European Centre for Medium-Range Weather Forecasts and EUMETSAT member states’ national services.
Launch
Metop A and B: October 2006 and September 2012, on a Russian Soyuz/ST Fregat rocket from the Baikonur Cosmodrome in Kazakhstan.
Metop C: November 2018, on a Soyuz ST-B rocket from the European Space Port in Kourou, French Guiana.
Manufacturer
Astrium, a subsidiary of the Paris-based European Aeronautic Defence and Space Company (EADS), was the primary contractor. Later mergers folded Astrium and EADS into the Airbus Group. Major instruments were provided by CNES, the French space agency, and NOAA.
Orbit
Designed to operate on a polar orbit, Metop passes over the entire surface of Earth twice a day. A Metop satellite crosses the equator at 09:30 local time each day as part of its morning responsibility, while a NOAA satellite crosses at 14:30 local time in covering the afternoon orbit. Together, these two orbits maximize coverage for observations and provide the inputs needed for the computer models used in weather forecasting. Metop doesn’t pass precisely over the geographic poles but at a slight inclination. This means that during the 100 minutes required for Metop to complete an orbit Earth rotates about 25 degrees, so a different region is covered with each orbit. The instruments on board measure varying swaths during each pass, but all instruments achieve near complete global coverage within five days. Overlapping swaths provide enhanced capabilities. Data is provided to users within about two hours after it is recorded.
What’s next
Six satellites, series A and B with three spacecraft each, are planned for deployment through 2040, beginning with Metop Second Generation A1 (Metop-SG-A1) in late 2025. The prime contractor is Airbus in Toulouse, France. The SG-A and SG-B series will fly at the same low Earth altitude along the same morning orbit as the current Metop satellites. The spacecraft will carry three new instruments, two of which have never been flown on an operational satellite. Weather prediction at regional and global scales will benefit from the satellites’ enhanced capabilities for measuring temperature and humidity, polar atmospheric motion, precipitation, clouds, ocean wind, and soil moisture. Metop-SG A also carries the Copernicus Sentinel-5 spectrometer for measurements of trace gases, which will help improve air quality forecasts. Each of the new satellites has a projected service life of seven years. Metop-A, the first in the series, had a projected life of five years but continued supplying data for 15.