The Arianespace commercial launch consortium expects to carry out four more Ariane 5 missions this year, and perhaps a fifth, despite the multiple satellite- and rocket-related delays that have kept the rocket grounded since February, Arianespace Chief Executive Jean-Yves Le Gall said.

The latest glitch occurred after an Ariane 5G rocket’s storable-propellant second stage was fueled. A post-fueling analysis concluded that the hydrazine-based MMH fuel might have been contaminated, forcing the Evry, France-based company to remove the entire stage from the rocket and replace it with another one.

“It is difficult to empty, clean and then refuel the stage while it is still on the rocket,” Le Gall said in a July 29 interview. “We had another stage on-site, and it was relatively straightforward for us to replace it.”

Arianespace now plans to launch Thailand’s iPSTAR, or Thaicom 4, broadband satellite Aug. 11 from the Guiana Space Center in French Guiana. At 6,500 kilograms, Thaicom 4 is too heavy to permit the Ariane 5G rocket to accommodate a second satellite on the same launch.

What satellites will be launched next remains unclear. Indonesia’s Orbital Sciences Corp.-built Telkom-2 telecommunications satellite, which had been set for launch in June, was returned to its Dulles, Va., manufacturing plant when Orbital Sciences found a short circuit during pre-launch testing at the French Guiana space port.

Orbital Sciences officials say they expect Telkom-2 to be sent back to the equatorial launch site in August. It is scheduled to be launched on an enhanced-version Ariane 5 ECA rocket together with DirecTV Group’s Spaceway 2 high-definition television broadcasting satellite.

It will be the third launch for the Ariane 5 ECA, which failed in its maiden flight in December 2002 but launched successfully following extensive modifications in February.

But having witnessed too many satellite-arrival dates come and go without a delivery, Le Gall said it is not yet certain whether the launch of Telkom-2 and Spaceway 2 will be next up after Thaicom 4, despite the fact that El Segundo, Calif.-based DirecTV wants its satellite in orbit as soon as possible.

For Arianespace, launching the Ariane 5 ECA is of prime importance, as the rocket will be the company’s standard product offering in the coming years. Satellite insurance underwriters say it will be easier to provide reasonably priced coverage for Ariane 5 ECA passengers following a second successful launch.

But another customer — the French Defense Ministry — also is becoming impatient. The French Syracuse 3A military telecommunications satellite is awaiting launch together with PanAmSat’s Galaxy 15 telecommunications satellite aboard an Ariane 5G rocket.

French defense officials have said publicly that they want Syracuse 3, which is already eight months late, launched in September at the latest.

Delivery of Galaxy 15, which uses the same Orbital Sciences-built platform as Telkom-2, was postponed while Orbital made a modification following an anomaly on an already-launched PanAmSat-owned spacecraft. The same problem delayed the launch of PanAmSat’s Galaxy 14 spacecraft aboard a Russian Soyuz rocket from the Russian-run Baikonur Cosmodrome in Kazakhstan.

The Soyuz launch of Galaxy 14 now is scheduled for around Aug. 12, according to Kathryn Lancioni, a spokeswoman for Wilton, Conn.-based PanAmSat.

Le Gall says it now appears that the Galaxy 15 and Syracuse 3A satellites might be ready before Telkom-2.

Under its current planning, Arianespace expects to be able to launch Eumetsat’s MSG-2 meteorological satellite and India’s Insat 4A telecommunications spacecraft together in December aboard an Ariane 5G rocket.

Once the second Ariane 5 ECA launch occurs, Arianespace’s satellite-matching difficulties should ease. The rocket is capable of lifting two satellites with a combined weight of more than 9,000 kilograms into geostationary transfer orbit, the initial destination of most telecommunications spacecraft.

Starting in 2008, Arianespace will manage launches of Russia’s Soyuz rocket from Europe’s space port, where it will be able to lift 3,000-kilogram telecommunications satellites of the kind that Orbital Sciences makes as a specialty.

Until recently, Arianespace with its Soyuz was the lone occupant of this market niche.

But Arianespace’s occasional launch-backup partner, Sea Launch LLC of Long Beach, Calif., now intends to operate a variant of its Russian-Ukrainian Sea Launch vehicle from the Baikonur Cosmodrome as well, in a version called Land Launch. The Land Launch rocket recently won its first customer — PanAmSat — for a mid-2007 launch of the PAS-11 satellite.

Le Gall said that while Sea Launch and Arianespace are partners, they are not wedded.

“It’s not a marriage; it’s a less-formal relationship,” Le Gall said. “Each company is permitted to have its own adventures on the side. But when we are back together we are always happy to see each other.”

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