PARIS — Four government and two commercial payloads are vying for space on four Soyuz rockets scheduled for launch this year from Europe’s Guiana Space Center, with Europe’s Arianespace launch service provider hoping satellite delivery delays will allow it to avoid performing a delicate triage between high-value customers.

For Evry, France-based Arianespace, commercial satellite operator SES of Luxembourg and the 20-nation European Space Agency (ESA) are about as high-value as they come.

SES is the major shareholder in O3b Networks of Britain’s Channel Islands, which has booked two Soyuz rockets carrying a total of eight satellites to begin operating a global Ka-band broadband service from an unusual, medium Earth orbit over the equator.

O3b has another four satellites under construction and scheduled for launch on a Soyuz, but it can start commercial service with eight spacecraft.

Officials from O3b’s satellite prime contractor, Thales Alenia Space, have said they are on track to deliver the first eight satellites in time for launches in mid-2013.

Romain Bausch, chief executive of SES, said here Jan. 15 during a space policy conference organized by Euroconsult that O3b is counting on the first launch occurring in May or June, and the second in July or August. Bausch said he is hopeful that the crunch in the Soyuz manifest this year will not fully develop until fall.

ESA has four Soyuz missions booked this year, all for satellites that are unlikely to be ready for launch until midsummer at the earliest. The first is the Gaia science satellite, under construction by Astrium Satellites of France. Officials said Gaia’s specific launch-readiness date is not yet known, but that it is almost certain to be ready for 2013.

The second launch is of the Sentinel-1A Earth observation satellite, which is part of ESA’s contribution to Europe’s Global Monitoring for Environment and Security (GMES) program, managed by ESA and European Commission. Sentinel-1A is under construction by Thales Alenia Space Italy.

There was a time when ESA had threatened to delay Sentinel-1A’s launch until the European Commission confirmed that it was prepared to finance the satellite’s in-orbit operations, as was foreseen in the GMES agreement between the two government bodies. But the commission has been unable to secure the necessary commitments from its 27 member governments for its next seven-year budget, which begins in 2014.

More specifically, the commission has proposed leaving GMES out of the seven-year package. In recent weeks, indications from the commission are that GMES has been returned to the Multi-year Financial Framework package with a budget of around 3.8 billion euros ($5 billion) over seven years.

ESA in late 2012 agreed to proceed with Sentinel-1A’s launch, hoping that its occurrence would put pressure on the commission to resolve the GMES funding issue. France’s research minister, Genevieve Fioraso, told the conference here that indications are that GMES will retain a place in the seven-year budget. But she cautioned that the situation remained fluid and unpredictable. A commission decision is expected by this spring.

ESA also has scheduled two Soyuz launches, each carrying two satellites, for Europe’s Galileo satellite positioning, navigation and timing project.

ESA Director-General Jean-Jacques Dordain said during the conference that the four satellites would be ready for launches between mid-September and mid-December.

Other officials said the Galileo spacecraft, under construction by OHB AG of Germany, will need to undergo extensive testing before launch insofar as they are the first of the 22 OHB-built Galileo spacecraft.

“The European Commission is the owner of the Galileo program and has said it wants 18 Galileo satellites in orbit by the end of 2014,” one industry official said. “That is the objective. Whether the next two launches occur in late 2013 or early 2014 makes absolutely no difference for the program. If there is no need to rush them to the launch pad, why do it?”

Dordain said that, for Soyuz operations at the European spaceport, “this is not a bad problem to have — deciding which to launch. It is a rich man’s problem.”

Asked who would decide the issue in the event of conflict, Dordain said: “Ask Arianespace.”

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