TYBEE ISLAND, Georgia — Europe’s Ariane 5 heavy-lift rocket on Aug. 20 launched two commercial telecommunications satellites in the vehicle’s 67th consecutive success and the fourth of six missions planned for 2015.

The launch, from Europe’s Guiana Space Center on the northeast coast of South America, placed the Eutelsat 8 West B and Intelsat 34 satellites into the intended transfer orbit.

Both satellites were reported to be in good health by their owners.

The launch came amid a lack of stability in the global commercial launch market. The Ariane 5 rocket’s principal competitor in the past two years, the Falcon 9 rocket operated by SpaceX of Hawthorne, California, is recovering from a June 28 failure – the vehicle’s first total loss – and its return-to-flight schedule is not yet clear.

Russia’s Proton rocket, the third principal commercial provider, is recovering from a May failure and is scheduled to return to service Aug. 28.

Riding in the Ariane 5 rocket’s upper position as the heavier of the two satellites, Eutelsat 8 West B weighed 5,782 kilograms at launch. Built by Thales Alenia Space of France and Italy, the satellite will operate from Eutelsat’s slot at 7/8 degrees west in geostationary orbit, a position that Eutelsat uses with partner Nilesat of Egypt. The satellite’s 40 Ku- and 10 C-band transponders will provide television programming over the Middle East and North Africa for Paris-based Eutelsat.

The satellite’s payload includes an interference-mitigation system, an increasingly common feature for satellites over the Middle East and North Africa, where politically motivated signal jamming has been an issue in recent years.

The interference-mitigation capability was developed in research programs at the European Space Agency and the French space agency, CNES. It will enable Eutelsat to exert firmer control over the satellite’s uplink frequencies from the ground.

“This function involves embarking new-generation frequency converters behind the satellite’s receive antennas,” Eutelsat said in a statement. “This will put Eutelsat in the unique position to be able to change the frequency of an uplink signal without any impact on the downlink frequency received by user terminals, marking a major breakthrough in the bid for continuity of service for broadcast signals jammed by rogue uplink signals.”

In a video recorded before the launch, Thales Alenia Space Chief Executive Jean-Loic Galle said his company delivered the Eutelsat 8 West B more than one month ahead of schedule.

Intelsat 34, occupying the Ariane 5 lower berth, weighed 3,300 kilograms at launch. It was built by Space Systems/Loral of Palo Alto, California, which is owned by MDA Corp. of Canada, and carries 18 Ku-band and 22 C-band transponders. Luxembourg- and McLean, Virginia-based Intelsat will operate the satellite from 304.5 degrees east.

The satellite’s C-band will be used to provide television programming in Latin America, especially Brazil, with its Ku-band capacity to provide aeronautical and maritime mobile communications with beams over the North Atlantic air and sea routes. It will replace Intelsat’s Galaxy 11 and Intelsat 805 satellites.

Intelsat and Eutelsat are, respectively, the second- and third-largest commercial satellite fleet operators, when measured by revenue. They are the two largest commercial customers for the Evry, France-based Arianespace launch consortium. The Aug. 20 launch is the 55th Intelsat satellite launched by Arianespace and the 30th Eutelsat satellite.

Arianespace Chief Executive Stephane Israel said after the launch that four more Intelsat satellites and three more Eutelsats are booked for future Ariane 5 launches.

With six launches now conducted in 2015 – four Ariane 5s, one Europeanized Soyuz medium-lift rocket and two Vega light-lift vehicles – Arianespace hopes to conduct six more missions by the end of the year. That would beat the 2014 record of 11 launches.

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