PARIS — The French Defense Ministry on Dec. 2 announced it has ordered two high-resolution optical and infrared reconnaissance spacecraft from Astrium Satellites and Thales Alenia Space in a $1.1 billion contract that calls for the first satellite to be launched in December 2016.

The spacecraft will succeed France’s current Helios 2 reconnaissance satellites, both of which are healthy in orbit and expected to well exceed their nominal five-year service life. Helios 2A was launched in December 2004, with Helios 2B launched in December 2009.

French defense officials had wanted the Helios 2 successors to be ready in 2014 or 2015 to assure that there is no gap in coverage. But they have concluded that the Helios 2 performance, plus the fact that two lower-resolution, civil/military Pleiades optical satellites are being readied for launch in 2011, provides enough cushion to delay the new system’s entry into service until early 2017, according to an official with France’s arms procurement agency, DGA.

In addition to the Helios 2 satellites, French defense authorities continue to make use of Helios 1A, which was launched in 1995, also on a planned five-year mission.

The new contract, which was signed Nov. 30, calls for Astrium to provide the satellite platforms and avionics, and to integrate and test the spacecraft before delivering them to the French space agency, CNES, which the French Defense Ministry has delegated to be overall contract manager. Thales Alenia Space will provide the high-resolution optical imaging cameras.

The two satellites will be built under a contract valued at 795 million euros ($1.07 billion). CNES will be responsible for securing their launch under separate contracts. By 2016, Europe’s Guiana Space Center spaceport will be home to Russia’s Soyuz medium-lift rocket and to the Italian-led Vega small-satellite launcher, in addition to the European Ariane 5.

The DGA official noted that even with the launches added, the two new satellites will cost no more than around half the cost of the two Helios 2 spacecraft, which were budgeted at 2 billion euros over 10 years.

The new satellites are expected to be based on Astrium’s AstroSat 1000 platform, the same used for Pleiades, which is for satellites with a launch mass of between 1,000 and 1,500 kilograms.

The two post-Helios satellites are called CSO, a French acronym for Optical Space Component. The name reflected the optimism in France that six nations — Belgium, France, Germany, Greece, Italy and Spain — would agree to build a common ground infrastructure for their future military space-based reconnaissance needs. The common infrastructure, called Musis, or Multinational Space-Based Imagery System, was to consolidate optical satellites being built in France and Spain, and radar satellites from Germany and Italy, into a single ground network for use by these nations’ troops and for civil defense purposes.

Despite the fact that Musis will allow each nation to launch its own satellites, the program has struggled with issues including the value of an optical image relative to radar products. Another sticking point is that the four nations building their own satellites wanted these programs to cover their Musis contributions, without having to help finance the common ground network.

The contract with Astrium and Thales Alenia Space includes an option for a third satellite that could be built if and when other nations elect to join the French CSO program. Belgium, Greece, Italy and Spain each purchased a 2.5 percent stake in France’s Helios 2 program.

The DGA official said that because of data-continuity concerns, France was obliged to begin the CSO contract before any other nation had agreed to join. But he said several nations have expressed interest, and that their eventual contributions will determine whether a third CSO satellite is built.

France has struck bilateral deals with Germany and Italy to get access to these nations’ radar-satellite data in exchange for Helios imagery, but the broader Musis program has yet to see the light of day. French defense officials had warned their Musis partners that the French deadline for freezing design of a next-generation system was late 2010 and would not be extended, with or without a Musis agreement.

In its Dec. 2 statement, the Defense Ministry said the CSO program would provide work for 500 engineers over the life of the program.

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