Eumetsat has ordered a fleet of spacecraft for polar orbits.

Tim Furniss/LONDON

EUMETSAT, EUROPE'S weather-satellite organisation, has marked its tenth year of operations by authorising the development of a new $2.3 billion satellite system to send into polar orbits. The satellites will be used to improve weather forecasting and global-climate monitoring. The first launch of a Eumetsat Polar System (EPS) craft, the Meteorological Operational (METOP) 1, has been scheduled for 2002.

Eumetsat is also developing the Meteosat Second Generation (MSG) three-satellite geostationary orbit (GEO) fleet, the first of which will be launched in 2000.

Data continuity until 2012 is ensured with the commitment to the operation of a full complement of GEO and polar satellites by the 17-member West European state organisation which combines with other national agencies as part of the World Meteorological Organisation. In November 1995, Eumetsat took full operational control of the first-generation Meteosat 5 prime satellite and its back-up, the Meteosat 6, in geostationary orbit. It did so from its new control centre and headquarters in Darmstadt, Germany, opened in June 1995. The satellites were previously controlled by the European Space Agency.

The Eumetsat ground system also includes a primary ground station in Fucino, Italy, and data-uplink stations in Rome, Italy, Bracknell, in the UK, and Toulouse, France. The Meteosat 7, the final craft of the original fleet, the first of which was launched under the auspices of ESA in 1977, will be launched - as usual by an Arianespace Ariane - in 1997.

Imaging radiometers on these satellites - in orbit over the equator, showing views dominated by Africa - return a set of visible, infra-red and water-vapour images every 30min. Images and image sequences can be processed to provide data ranging from sea-surface temperatures to cloud motion winds.

These images can be accessed rapidly by a wide range of users, from airlines to schools, equipped with small terminals, using the Meteosat data-distribution service and data-retransmission system. The satellites' data-collection system is used to amass environmental data from automatic ground-, air- or sea-based weather stations.

Over 2,000 systems in 100 countries are installed for the direct reception of Meteosat images, including 300 high-performance primary data-user stations.

The Meteosat works in tandem with other GEO spacecraft, placed at different positions over the equator, providing global coverage. These craft are the USA's GOES West and GEOS East, Japan's Geostationary Meteorological Satellite, the GMS 5, and India's Insat communications satellite fleet, which also returns weather pictures from GEO.

The GOES K and L are scheduled for launches after 1999. The GMS 5 will be replaced by a new-generation multi-functional transport satellite in 2000, which will also serve as an air-traffic-control craft. The Insat 2E is scheduled for launch in 1997. Russia launched its first GEO satellite, GOMS/Elektro 1 in 1994, after many years of delays, but data from it are not widely available. The Elektro 2 is scheduled for a 1998 launch.

The Ariane-launched MSG spacecraft will be over twice as large as the original 720kg Meteosats and have over four times the capacity. The spin-stabilised Aerospatiale-built MSGs are based on the Meteosat design and weigh 1,700kg in orbit, operating on 5kW of power, and equipped with a 12-channel enhanced radiometer. This will provide 12 types of image every 15min, with a 1km-resolution visible wavelength image.

The increased radiometer capacity of the MSGs will enable the craft to be used to conduct a new Airmass Analysis Mission, providing temperature, humidity and ozone measurements. The ESA is responsible for the development of the first MSG, while Eumetsat maintains control over the launch and control of all three and the development of the MSG 2 and 3, which will be launched in 2002 and 2006, respectively.

The new EPS METOP polar spacecraft - manifested for Ariane 5 launches - are being developed by the ESA, but Eumetsat will have overall control of the programme. The EPS/METOP 2 and 3 will be launched in 2006 and 2010, respectively. The METOP 1 will be equipped with 11 instruments to provide measurements in a joint programme with the USA's NOAA spacecraft, in which the NOAA 14 and 12 are the prime satellites. The NOAAs K, L, M and N are scheduled for launches between 1997-2003.

Source: Flight International