LIVERPOOL, England–Europe’s heavy-lift Ariane 5 rocket on July 15 successfully placed a Brazilian commercial telecommunications satellite and a European meteorological spacecraft into geostationary transfer orbit in the rocket’s 66th consecutive success and the third of a planned six launches for 2015.

The manufacturers of both satellites said they were healthy in orbit and sending signals.

With the Ariane 5’s main commercial launch competitors – SpaceX’s Falcon 9 and Russia’s Proton rockets – grounded following June and May launch failures, respectively, each Ariane 5 mission has taken on a special significance for the commercial market.

Lifting off from Europe’s Guiana Space Center, which is French territory on the northeast coast of South America, the Ariane 5 placed the Star One C4 satellite, owned by Embratel Star One of Brazil; and the Meteosat MSG-4 meteorological satellite, into the planned transfer orbit.

The heavier satellite, Star One C4, weighed 5,560 kilograms at launch and launched in the rocket’s upper berth. Built by Space Systems/Loral of Palo Alto, California, the Star One C4 carries 48 Ku-band transponders and will operate at Star One’s slot at 70 degrees west longitude in geostationary orbit. It is designed to operate for at least 15 years.

The 2043-kilogram MSG-4 – which may be the last spin-stabilized satellite in geostationary orbit for some time — was built by Thales Alenia Space of France and Italy and will operate for at least seven years at 3.4 degrees west. The satellite is owned and operated by Europe’s Eumetsat meteorological weather satellite organization, based in Darmstadt, Germany.

The next generation of Eumetsat satellites will be three-axis stabilized. Telecommunications satellites moved to the three-axis-stabilization model some 20 years ago. The world’s major weather-satellite organizations have since followed suit, even if the spin-stabilized design – where the satellite rotates in orbit to maintain stability – still has its defenders.

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