PARIS — The launch of Europe’s Metop-1 polar-orbiting meteorological satellite inaugurates a long-term collaboration between U.S. and European weather-satellite authorities in which, for the first time, each side is dependent on the other.

The Oct. 19 launch ended four months of delays related to defective ball bearings on the satellite and, starting in July, a series of software and other apparently minor technical glitches related to the new digital control system on the Russian Soyuz 2-1a rocket and its surrounding launch installations.

The 19-nation Eumetsat, Europe’s weather satellite organization, is expected to take control of the satellite from the European Space Agency’s Esoc operations center Oct. 23.

Six months of testing of the satellite and its 11 observing instruments will follow, with full operations to begin next spring.

The Darmstadt, Germany-based Eumetsat operates Europe’s geostationary-orbiting Meteosat weather satellites, but Metop will be Europe’s first polar-orbiting meteorological system.

Operating at an altitude of 837 kilometers, the 4,085-kilogram Metop will be Europe’s contribution to the U.S.-European Initial Joint Polar System. Metop-1 will be followed, at four-year intervals, by the identical Metop-2 and Metop-3 satellites to assure uninterrupted coverage until at least 2020.

Metop will provide coverage of the mid-morning polar orbit, referring to the time it crosses the equator. The U.S. National Oceanic and Atmospheric Administration (NOAA) and the U.S. Department of Defense, whose once-separate systems are being merged to save money, will be responsible for the early morning and afternoon orbits.

The U.S.-provided satellites include the NOAA-18 spacecraft currently in orbit; the future NOAA-N Prime satellite, both of which will carry a Eumetsat-provided instrument. The U.S. Defense Meteorological Satellites Program spacecraft will complete the coverage of polar orbit.

Metop carries four NOAA-supplied instruments, including the Advanced Microwave Sounding Unit-A system that provides atmospheric temperatures. It is this instrument whose ball bearings needed to be replaced after Metop-1 was flown to its launch site at the Baikonur Cosmodrome in Kazakhstan.

Having NOAA and the U.S. Department of Defense as partners in a single weather system has meant accepting new and unfamiliar policies for Eumetsat, the most recent being one on data denial of real-time weather information to certain organizations in the event of a war or other emergency.

“The U.S. and Europe will be able to coordinate their respective satellite programs to lessen gaps in coverage,” Eumetsat Director-General Lars Prahm said Oct. 17. “The fact that we are now poised to realize this collaboration is a major milestone.”

The United States and Europe in the past have come to each other’s aid when one side’s geostationary orbiting satellites have been out of service, but they have never gone as far as the mutual reliance that is the foundation of the Initial Joint Polar System. In the many pre-launch events held in Darmstadt, Germany, where the Esoc operations center also is located, European government officials never mentioned the U.S. Department of Defense’s involvement.

Greg Withee, assistant administrator for NOAA’s satellite and information service, said the U.S.-European partnership “is absolutely crucial to the continuous flow of environmental data captured from space.”

Metop was built by a 40-company team led by Astrium. All three satellites were contracted at the same time to realize economies. With Metop-1 now safely in orbit, the two successor satellites will be placed into storage until they are needed.

Metop is budgeted at 2.4 billion euros ($3 billion), a figure that includes the satellites’ construction and launch, 14 years of operations and a complicated network of ground installations that proved more troublesome to complete than the satellites.

The European Space Agency is financing 23 percent of the program’s costs and was the principal satellite design authority.

Perhaps the most complicated instrument aboard Metop — and one that also posed design and schedule challenges — is IASI, the Infrared Atmospheric Sounding Interferometer. It provides an estimated 50 percent of Metop’s scientific output.

This instrument alone cost some 260 million euros ($325 million), with two-thirds of the financing provided by its designer, the French space agency, CNES. The figure does not include CNES personnel costs during IASI development.

Gilles Chalon, IASI project manager at CNES, said the instrument took 15 years to design, develop and test. IASI’s features include the ability to map atmospheric phenomena at an angle of up to 48 degrees on either side of Metop’s straight-down view.

Carrying its own on board processor, IASI will be able to compress 45 megabits per second of data into 1.5 megabits with its 12 microprocessors, lightening the load of Metop’s ground teams that process and transmit data.

IASI has some 8,400 spectral measurement channels, compared to 20 infrared channels on Metop’s High-resolution Infrared Radiation Sounder.