DARMSTADT, Germany — Europe’s meteorological satellite organization, Eumetsat, will need to overcome Portugal’s complicated objection to a next-generation satellite system by March at the latest to avoid serious program interruption, Eumetsat officials said Dec. 8.

Trapped by its own rules, which forbid new core-program investments from proceeding without 100 percent approval of its 26 member states, Eumetsat is unable to approve the full Meteosat Third Generation (MTG) satellite system because of Portugal’s refusal to permit work to start even if Portugal will not be asked to pay for it.

Eumetsat’s share of the MTG program will cost an estimated 2.4 billion euros ($3.2 billion). The organization has firm commitments for about 86 percent of that sum, and go-ahead authorization for 98.8 percent of the total.

That leaves Portugal’s 1.2 percent stake. At a Eumetsat council meeting Nov. 30-Dec. 1, Portugal said that with the country’s current credit crisis, it could not immediately subscribe to MTG despite the fact that no Eumetsat member government objects to it.

In interviews at Eumetsat headquarters here, Eumetsat officials said they were optimistic that Portugal would find a way to approve the investment well before the MTG cash runs out early in 2011.

They conceded that Eumetsat’s ruling convention forbids so-called mandatory programs, which include the Meteosat satellites, from moving forward without unanimous approval.

MTG is a six-satellite program of four imaging and two sounding satellites to be placed into geostationary orbit starting in 2017 for the first imaging craft, and mid-2019 for the first sounding satellite. The program already has suffered a one-year delay because of disputes among Eumetsat and European Space Agency governments about MTG work-share distribution.

Sergio Rota, head of geostationary programs at Eumetsat, said the one-year delay should not prove too costly for Eumetsat if, as is expected, the current generation of Meteosat Second Generation satellites are placed into service without incident.

The fourth and last of these second-generation satellites, MSG-4, is scheduled to be in operation for at least four years after the first MTG imaging satellite is launched, providing an overlap in the event of delays with the future system.

MTG represents a break from past Eumetsat systems. It will be the agency’s first three-axis-stabilized design — previous Meteosats were spin-stabilized, a satellite architecture that Europe stuck with long after the United States moved to three-axis stabilization — and will represent a new operating complexity because of its multiple satellites.

In presentations to prospective MTG contractors, Eumetsat officials also stressed the fact that the volume of data the MTG satellites will produce is many times what the organization is handling with the current Meteosat system.

The raw data link will be in Ka-band, a new MTG feature necessary to secure enough bandwidth to accommodate what the MTG satellites will be delivering to Eumetsat and its users. Because Ka-band is sensitive to rain, the future Ka-band receiving antennas will need to be placed at least 70 kilometers apart so that ground controllers are able to shift the downlink to an area with better weather conditions.

Rota said that despite the slightly higher MTG costs associated with the final industrial bid for the six satellites by a team led by Thales Alenia Space of France, the system will end up costing Eumetsat governments even less, on an annual basis, than the less complicated Meteosat Second Generation system.

Eumetsat governments in the next couple of years will be asked to make a similar assessment for a second-generation, polar-orbiting satellite system to succeed the current Metop satellites. Eumetsat and the U.S. National Oceanic and Atmospheric Administration have a long-standing cooperation agreement to share responsibility for the polar orbit, a cooperation that Eumetsat officials expect will continue.

Rota said that Eumetsat governments had asked that the MTG program cost no more, on an annual basis, than the second-generation system. The result: The current second-generation Meteosat satellite system is costing about 121 million euros per year including 20 years of operations and one year of commissioning. MTG will cost about 113 million euros per year.

Peter B. de Selding was the Paris bureau chief for SpaceNews.