Arianespace will loft the Eutelsat 25B and Indian G-Sat 7 satellites together on an Ariane 5 by the end of August, following the launch of Europe’s Alphasat I-XL and India’s Insat 3D atop the heavy-lift rocket July 25.

The missions will mark the third and fourth of a planned five Ariane 5 launches in 2013, says Arianespace CEO Stephane Israel, who took the helm of the European launch consortium in April.

Following the August launch, the company is expected to orbit the Astra 5B satellite for Luxembourg-based fleet operator SES, along with an undetermined co-passenger, though Israel says the Ariane 5 launch manifest is to remain flexible into early 2014.

“This year we should make five Ariane 5 launches as a whole, but there could be some flexibility for a sixth at the end of this year or the beginning of next,” Israel told Aviation Week.

In the meantime, Israel said his company is positioned to accommodate impromptu demand from commercial customers of International Launch Services (ILS), a number of which are facing launch delays as a result of a July 2 mishap involving a Proton rocket that disintegrated and crashed seconds after launch near the Baikonur Cosmodrome in Kazakhstan.

ILS markets commercial launches of Proton, which has suffered five launch failures since 2010.

Since the accident, the Russian federal government has suspended all Proton launches as it investigates, a move that will delay a planned July 20 launch of the SES Astra 2E satellite and a handful of other commercial Proton missions slated for this year.

“If some customers want to come to Arianespace, we will see if we can find a slot for them, although it is more probable in 2014 than 2013,” Israel said, adding that last year Arianespace launched seven Ariane 5s, two European variants of the Russian Soyuz and one Vega light launcher from Europe’s equatorial spaceport in Kourou, French Guiana.

Next year, he says, the company could launch even more. “If we have to increase the rate of Ariane 5 or Soyuz or Vega, I want to be able to do so,” he said, noting that Arianespace is working with French space agency CNES, the company’s largest shareholder, and the Guiana Space Center in Kourou, to increase the tempo of launch campaigns in French Guiana, in part by reducing the amount of time needed between launches of different rockets to reset ground tracking radar and other facilities.