Science and Technology Wimax

A consortium led by Thales Alenia Space of France will enter into negotiations for a 1.3bn-euro (£1.2bn) contract to build Europe's next weather satellites.

The TAS group was selected after a competitive process run by the European Space Agency (Esa).

The Meteosat Third Generation (MTG) system will comprise six satellites, with the first spacecraft likely to be ready for launch in 2016.

MTG is expected to bring a step change in weather forecasting capability.

The programme should guarantee European access to space-acquired meteorological data until at least the late 2030s.

"These spacecraft should improve dramatically the quality of meteorological data, and I'm convinced we will see the difference in the weather forecasts," said Dr Volker Liebig, the head of Earth observation at Esa.

MTG is a joint undertaking between Esa and Eumetsat, the international agency charged with looking after Europe's Meteosats.

In the new programme, Esa will oversee the research and development phase of MTG.This will include two prototype Meteosats: an imaging spacecraft to picture weather systems and a sounding spacecraft (one which can return information about different layers in the atmosphere).

Eumetsat will operate these prototype platforms once they are launched and pay for the production models that follow. It is envisaged the satellites will be launched at intervals of a few years.

The new spacecraft will be quite unlike their forebears. The second generation satellites (MSG), for example, are spin-stabilised and build up their images as they rotate across the field of view.

The MTG spacecraft will look more like standard telecommunications platforms. They will sit and stare at the Earth.

Their image data will have a much higher resolution (capturing details as small as 500m) and will come down in a fraction of the time - in as little as 2.5 minutes.

"The users asked for a higher spatial resolution and even a better signal to noise ratio, and for that we've had to increase the time the satellite is able to observe the Earth," Rolf Stuhlmann, MTG programme scientist at Eumetsat, told.

"So, the first and the second generation were spin-stabilised satellites - they return around their axes and the instrument on the satellite is only able to look at the Earth 5% of the time. All the other time, it is looking into space.

"To increase the time the instrument is capable of looking at the Earth, we've had to go for the first time to a three-axis stabilised satellite."The new spacecraft will carry many innovations that should translate into more accurate and more detailed weather forecasts.

One key development is an Infrared Sounding Instrument that has been pioneered on Europe's Metop polar-orbiting Earth-observation spacecraft but which will now be flown in a geostationary orbit by MTG.

The instrument will be able to detect layers of moisture in the atmosphere long before they have developed into weather systems."If you see clouds, you know you have water vapour; it's very easy to see," explained Ernst Koenemann, director of programme development at Eumetsat. "But even in blue skies you still have water vapour, and this vapour will eventually develop into weather systems.

"With the infrared sounder, we will see this vapour, and by doing that we will be able to predict much better if and how the systems will develop."

The sounding instrument should also give improved warning of extreme precipitation events, such as the one in December that saw about 25cm of rain fall in just 24 hours on Cockermouth in north-west England.

In addition, the sounding spacecraft will have an enhanced capability to study atmospheric chemistry - to track the behaviour of trace gases such as ozone, nitrogen dioxide and sulphur dioxide.

Another new MTG instrument of major note is the Lightning Imager, which should provide much better information on the state of electrification in storms. This is expected to have immense benefits for the aviation sector, allowing it to route planes more safely.

The Meteosat series stretches back to 1977. Currently, two platforms - Meteosat-8 and Meteosat-9 - provide the space data on which daily weather forecasts for Europe depend.

Esa member states committed just under a billion euros to the MTG programme at a ministerial meeting in late 2008. The details of the Eumetsat contribution, which will amount to more than 2.4bn euros, are expected to be finalised later this year.

Eumetsat will hold a special council meeting shortly to discuss the scope of its role in the project.

It has taken much longer than expected to sort out the industrial contract. France and Germany wanted to lead MTG and both committed 34% of the requested Esa funds.

Space agency officials have had to ensure the workshare in the contract rewards the commitment of the two nations, as demanded under Esa rules.

The Thales consortium includes OHB System from Bremen which will ensure Germany plays its part; although Germany had hoped a consortium led by EADS Astrium from Friedrichshafen would win through to direct the MTG project.

"Technically, it was very complicated," Dr Liebig told. "The offers were 18,000 pages each. If we don't count Galileo [Esa's satellite-navigation project], it is the biggest contract in the agency. There were a lot of questions and it took many months to answer them."

Reynald Seznec, president and CEO of TAS, commented: "Esa and Eumetsat have chosen Thales Alenia Space, in partnership with OHB of Germany, to develop the third generation of Meteosat weather satellites, thanks to the technical excellence and competitiveness of our proposal.

"We are very proud of being chosen to meet the challenge of building the most ambitious geostationary satellites ever developed in Europe."

Esa will now negotiate a final price with TAS, with the aim of completing the deal in June.

If the talks are not concluded satisfactorily, Esa reserves the right to open discussions with Astrium.