PARIS — The European Commission has awarded satellite fleet operator SES a second long-term contract to host a navigation payload aboard an SES spacecraft already under construction. The two deals have a combined value of at least 270 million euros ($389 million), according to commission and SES officials.

In the latest agreement, announced Jan. 12, SES will place an L-band navigation payload on its Astra 5B direct-broadcast television satellite, under construction by Astrium Satellites of Europe and scheduled for launch in mid-2013. Astra 5B will be operated at 31.5 degrees east longitude.

This follows an agreement announced in mid-2009 calling for an identical navigation payload to be placed on SES’s Sirius 5 satellite, under construction by Space Systems/Loral of Palo Alto, Calif., and scheduled for launch in late 2011. Sirius 5 will operate at 5 degrees east.

The two payloads will be the core orbital asset of Europe’s Egnos service, which became partially operational in 2009. Egnos, like similar payloads on satellites covering North America and East Asia, provides signal verification for the U.S. GPS timing and navigation satellite constellation.

Egnos service is provided by an aging mobile communications satellite operated by Inmarsat of London and by Europe’s Artemis data-relay satellite. Both of these spacecraft are scheduled to be retired in the next three years.

The Brussels, Belgium-based European Commission, which is the executive arm of the 27-nation European Union, intends to operate Egnos for 20 years, or well after Europe’s own Galileo navigation satellite constellation is in orbit and operational, according to commission documents outlining the contracts.

The commission’s current seven-year budget cycle ends in 2013. Because it cannot commit itself to payments beyond the current period, the contracts with SES have formal end points in late 2013. But the commission has promised SES that Egnos payload lease payments will continue until the end of the scheduled 15-year operational lives of the Astra 5B and Sirius 5 satellites.

Annual service payments, which will be adjusted for inflation, will be about 9 million euros per year per satellite, for a total of 270 million euros over 15 years.

Ferdinand Kayser, president of SES Astra, the SES division that operates Sirius 5 and the Astra satellite fleet, said the second Egnos contract “proves that our strategy to diversify our business and to provide global telecommunications services for governments and supra-national institutions, as well as multinational organizations, is bearing fruit.”

SES officials have long said providing space on their commercial direct-broadcast television satellites for government payloads is a promising business that should develop in Europe and in the United States.

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