‘s weather-satellite organization approved the design of a Meteosat Third Generation (MTG) system to be launched starting in 2015 and to include two identical satellite platforms carrying separate suites of instruments.

Tentatively budgeted at 2.5 billion euros ($3.75 billion), MTG will include construction of six satellites four imaging spacecraft to be launched in sets of two, with one serving as backup to the other; and two satellites equipped with infrared and near-infrared sounding instruments that would be launched some eight years apart.

Meeting Oct. 9- , the council of the 22-nation Eumetsat placed the MTG process squarely in the path of the European Space Agency (ESA), whose governments are scheduled to vote on their share of MTG at a Nov. 25- 26 meeting of ESA governments.

As was the case with the first two Meteosat generations, MTG’s first spacecraft will be designed by ESA, which will finance 70 percent of the construction and launch of the first imager and first sounder satellites. Eumetsat governments said they would finance the remaining 30 percent of the first spacecraft.

Eumetsat is leaving it up to ESA to determine the precise cost of the MTG prototype spacecraft, but ESA has estimated that the total cost could approach 1 billion euros, with ESA paying 700 million euros of that.

If these figures hold once the satellite construction and ground-segment contracts are signed, that would put the MTG bill to Eumetsat at about 1.8 billion euros, which is close to what the agency is paying for the Meteosat Second Generation system now in orbit.

Four second-generation Meteosats are being built, each with a seven-year operational life in geostationary orbit. The fourth will be launched late enough to continue in operation until 2015 to serve as a backup for the first MTG imaging satellite.

The MTG spacecraft will be designed to last eight years, and will represent a break from the earlier Meteosat design, which has featured spin-stabilized platforms that rotate slowly in orbit to maintain their position.

The MTG satellites will be three-axis stabilized, and will be small enough to be launched by the European version of Russia’s Soyuz rocket, to be operated from Europe’s Guiana Space Center spaceport starting in 2010.

The operational MTG system will feature two satellites with complementary payloads, another difference from earlier Meteosat generations that partly reflects Eumetsat’s expanding role in environmental monitoring in addition to classic weather forecasting.

The MTG sounder satellites will include an ultraviolet, visible and near-infrared sounder that will be part of ESA’s Sentinel program of spaceborne sensors to be launched as part of a broad Earth observation program called Kopernikus.

It remains unclear whether ESA will structure the MTG contracting-bid competition to favor the selection of a single company to build all six satellites, and thereby reduce per-satellite costs.

The first imaging MTG satellite would be launched in late 2015, assuming ESA and Eumetsat move quickly enough to permit a contract to be signed in 2011. This contract date assumes that ESA, at its meeting in November, approves a so- called Phase B MTG program that would hone the design and lead to a contract proposal. The second imaging satellite would be launched in 2020, the third in 2024 and the fourth and final model in 2028, providing uninterrupted MTG service for a 20-year period.

Each satellite would be designed to last eight years in geostationary orbit and could carry a principle imaging instrument, a lightning imager, a data collection system and a sear-and-rescue payload to continue today’s Cospas-Sarsat service.

The first MTG sounding satellite would be launched in 2018, with the second launched in 2026.

Eumetsat announced Oct. 10 that the council instructed Eumetsat Director- General Lars Prahm and ESA to search for ways to “further present cost-saving options” for MTG.