PARIS — Satellite fleet operator Intelsat on June 16 said it has invested $1.3 billion in the four satellites it will be launching in the next 12 months, with three of them replacing existing capacity in the Asia-Pacific region and the fourth to open a new orbital slot with the Australian military.

Luxembourg- and Washington-based Intelsat is at the peak of its current capital-spending cycle. The $1.3 billion includes the satellites’ construction, launch and first year of insurance in orbit.

The first of the four satellites in the queue is the IS-18, whose launch Intelsat has had trouble securing as its intended rocket provider ran short of rocket components. Sea Launch Co. of Long Beach, Calif., will now be responsible for the launch, to occur in September or October aboard a Zenit 3 vehicle from Russia’s Baikonur Cosmodrome in Kazakhstan.

IS-18 will replace the Intelsat 701 satellite at 180 degrees east.

Next up for Intelsat will be the IS-19, to replace the Intelsat 8 satellite at 166 degrees east following a launch scheduled to occur by June 2012.

The IS-20 satellite, to be operated at 68.5 degrees east, is also scheduled for a launch in the second quarter of 2012 and will replace the IS-10 and IS-7 satellites.

The IS-22 spacecraft, to be launched in the first half of 2012, will open a new orbital position for Intelsat at 72 degrees east. In addition to a suite of C- and Ku-band transponders, IS-22, under construction by Boeing Space and Intelligence Systems of El Segundo, Calif., will carry a UHF-band payload for the Australian Defence Force.