PARIS — Mobile satellite services operator Iridium Communications on June 16 announced it had signed a $492 million contract with start-up launch-services provider SpaceX to place an undisclosed number of Iridium’s next-generation satellites into low Earth orbit between 2015 and 2017.

SpaceX’s Falcon 9 rocket, which on June 4 made a successful debut launch, will carry “multiple” Iridium satellites on each flight from Vandenberg Air Force Base in California, Iridium of McLean, Va., said in a joint announcement with Space Exploration Technologies (SpaceX), which is based in Hawthorne, Calif.

Iridium’s second-generation satellites, called Iridium Next, are expected to weigh 800 kilograms each and to be placed into a 780-kilometer orbit.

Iridium’s total $2.9 billion budget for the Iridium Next system has set aside $800 million to launch and insure 72 of the satellites, plus perform upgrades to the network’s ground infrastructure. That works out to about $11 million per spacecraft, which would be an exceptionally low price in today’s commercial-launch market.

Part of SpaceX’s appeal to the commercial satellite industry has been its advertised commitment to prices that are lower than prevailing commercial rates.

In its June 16 announcement, Iridium said it is “in discussions with, and expects to contract with, at least one additional launch services provider” for Iridium Next.

Industry officials have said that SpaceX’s Falcon 9, which comes in several sizes, can launch up to nine Iridium Next satellites at a time. Whether Iridium has elected to use Falcon 9 this way is not known.

Iridium announced in March that it had signed a $19 million contract with an unnamed launch-services provider to lock in prices for at least part of the Iridium Next constellation in anticipation of a formal contract. Industry officials said that reservation was with SpaceX.

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