Global satellite service providers that include Inmarsat and Eutelsat will face delays in the deployment of new or upgraded spacecraft as a consequence of a launch failure on Saturday involving a Russian Proton rocket owned and operated by the International Launch Services venture.

Approximately eight minutes after liftoff from Kazakhstan’s Baikonur Cosmodrome, a Proton-M launch vehicle carrying the Mexican government-owned Mexsat-1 satellite exploded. Officials with the Russian federal space agency Roscosmos reported that that an anomaly with the rocket’s third-stage engine was detected at an altitude of 100 miles at which “the third stage, upper stage and spacecraft . . . completely burned in the atmosphere.”

Saturday’s incident constitutes the fourth major Proton failure since 2012 and comes almost a year to the day after the last such failure on May 15, 2014. Sources indicate that investigations associated with each of the three previous Proton failures in December 2012, July 2013, and May 2014 delayed launch schedules for 108 days, 89 days and 136 days, respectively. Confirming that Inmarsat’s third and final satellite for the Global Xpress broadband network had been the next spacecraft in the Proton queue and had been slated for launch next week, Inmarsat CEO Rupert Pearce lamented that the failure “will inevitably delay our launch plans.” Although Pearce voiced doubts that a launch delay of several months would alter the economics of his company’s Global Xpress investment, he admitted that Saturday’s event “does beg yet another question around the impact on Inmarsat’s competitive positioning.”