Images of real sequences of clouds moving across Europe have graced our daily TV weather forecasts for the past 23 years. Now, however, the satellites that delivered them are about to be replaced.
When the new satellites take over, which will be sometime in 2002, the images on our screens will be even clearer and sequences of cloud development will be smoother and more realistic. Meteosat Second Generation will take images at more wavelengths and at shorter intervals than its parents, making it particularly suitable for short-term forecasting of sudden troublesome weather phenomena, such as snow, thunderstorms and fog. TV weather bulletins will be able to advise us with considerable accuracy about wheather to take an umbrella or avoid a particular stretch of road because bad weather is expected later in the day!
MSG is a joint project between ESA and Eumetsat, the organisation set up in 1986 to establish, maintain and operate a European system of meteorological satellites. Three satellites are planned at present and a ground segment. ESA is responsible for designing and developing the first satellite, and for procuring the other two on behalf of Eumetsat. Eumetsat is responsible for defining the payload based on user needs, procuring the ground segment and launchers, and eventually operating the system.
At any one time, two satellites will be functional in geostationary orbit at 0 degrees longitude which is above equatorial west Africa: one will be operational, the other on stand-by. The first satellite, MSG-1 is due for launch on board an Ariane-4 launcher in early 2002. MSG-2 will follow on an Ariane-5 about 18 months later. MSG-3 will be built and put in storage until it is required to take over as MSG-1 nears the end of its life. Each satellite will have a nominal seven-year lifetime, and combined, they will ensure continuity of weather forecasting in Europe for at least 12 years.