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N° 8–1993: European weather satellite moves closer to United States

24 February 1993

A new era of international cooperation in the sharing of weather data was marked today when a European weather satellite completed a move to 75 degrees west longitude at 22,500 miles (36,000 km) above the equator. The satellite now provides weather images spanning both East and West Coasts of the United States, Central and South America.

Meteosat-3 was launched in 1988 and served as Europe's operational satellite until June 1989. It was developed by the European Space Agency (ESA) and operated by ESA on behalf of the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT). The announcement of its move was made at a joint news conference by these agencies and the National Oceanic and Atmospheric Administration, which operates the United States' geostationary weather satellites known as GOES satellites.

The United States normally operates two meteorological satellites in geostationary orbit, one each over the East and West Coasts. However, it has had only one since the failure of GOES-6 in 1989.
A planned replacement satellite was lost due to a launch vehicle failure in 1986.
The remaining operational satellite, GOES-7, was repositioned midway over the United States. The next GOES launch is projected for April 1994 with a second GOES launch one year later. Meanwhile, if GOES-7 should fail, it is technically possible for Meteosat-3 to move farther west and provide continuing coverage of the United States, Central and South America.

Meteosat-3 originally operated at 0 degrees longitude over the equator. It was manoeuvred to a position of 50 degrees west over the equator in August 1991 to supplement NOAA's GOES system. It began the journey to its new location of 75 degrees west longitude 27 January, moving approximately one degree per day in support of the Extended Atlantic Data Coverage mission.

At 75 degrees west, Meteosat-3 is no longer within the field of view of the Meteosat station located near Darmstadt, Germany. To be able to continue the operations from ESA's European Space Operations Center (ESOC) it was necessary to build a Meteosat Relay station in Wallops, Virginia. The station, implemented by European industry under ESA management, is connected with ESOC's control center through a trans-Atlantic satellite link. Images from Meteosat-3 are available free of charge and will be used by weather forecasters in both the northern and southern American continents and will also be available to European weather services using already established communications links involving Meteosat 4.

There is a tradition of cooperation among operators of geostationary satellites. In 1978, a U.S. GOES satellite was positioned over the Indian Ocean at the request of the World Meteorological Organisation, and operated by the European Space Agency from a ground station in Spain. In 1985, NOAA aided Europe by repositioning a GOES satellite farther east over the Atlantic during the loss of the Data Collection System on Meteosat-2.

Note to Editors :
Prints of the first image taken on 19 February 1993 by Meteosat-3 from its new location at 75 degrees West, together with some explanations of the meteorological situation that day, are available from ESA Public Relations at one of the addresses figuring on the first page of this press release.