PARIS — Thales Alenia Space Italy has signed a contract valued at 200 million euros ($260 million) with Astrium GmbH of Germany to provide telecommunications, thermal control and electric-power systems for Europe’s $1 billion BepiColombo Mercury orbiter, Thales Alenia Space announced Dec. 5.

The contract comes five years after the two companies signed an original authorization to proceed that allowed hardware design to begin.

BepiColombo, whose budget and schedule have slipped on several occasions as the satellite grew in weight, forcing a launch aboard a heavy-lift Ariane 5 instead of a medium-lift Soyuz rocket, is currently scheduled for launch in 2015.

The European Space Agency (ESA) is managing BepiColombo in cooperation with Japan’s JAXA space agency. ESA’s work includes the Astrium- and Thales Alenia Space-built Mercury Planetary Orbiter. JAXA is providing the Mercury Magnetospheric Orbiter.

Both orbiters will be launched aboard the same Ariane 5 vehicle on a 6.5-year journey to Mercury orbit attached to the Mercury Transfer Module. Once in Mercury orbit, the two satellites will separate.

The satellites are scheduled to operate for a year at Mercury to investigate the origins and evolution of the planet, with a possible one-year extension. One of the principal design challenges is to withstand the temperature extremes in Mercury orbit, as high as 350 degrees Celsius on the side facing the sun.

Peter B. de Selding was the Paris Bureau Chief for SpaceNews.