A spate of Proton launch mishaps has created a de facto duopoly of Arianespace and SpaceX, two companies vying to dominate the global commercial launch market. 

With Russia's heavy-lift Proton grounded following its eighth launch failure in five years – and with the U.S. Falcon 9 rocket yet to prove it can operate on a monthly basis – the global commercial satellite industry is facing a dearth of options for lifting large spacecraft to orbit.

At the moment, the only reliable option for launching large commercial telecom satellites is Europe's workhorse Ariane 5. Managed by commercial launch consortium Arianespace, the vehicle lifts-off five or six times a year carrying medium and heavy payloads to geostationary orbit in a single mission. But with a manifest booked into 2017, Ariane 5 is not a viable ‘Plan B’ for satellite fleets facing potential delays owing to Proton or SpaceX setbacks, a situation that is already affecting the bottom lines of commercial operators.

Rupert Pearce, CEO of London-based Inmarsat, recently revised his 2014-16 growth forecast downward following a May 16 Proton launch that resulted in the loss of Mexico's Centenario commercial communications satellite. The rocket, which appears to have suffered an upper stage anomaly several minutes after liftoff, was expected to launch Inmarsat's third Global Xpress Ka-band communications satellite this month, but Proton will remain grounded while investigators search for the root cause.

For Pearce and other fleet operators, such setbacks are becoming routine. “This is the third time our Global Xpress program has suffered launch delays because of Proton launch failures,” Pearce said following the May launch failure, adding that the slip has prompted Inmarsat to revise its revenue-growth projections. In the meantime, the company is banking on construction of a back-up Global Xpress satellite underway at prime contractor Boeing, with plans for launch atop a new Falcon Heavy rocket in the second half of 2016, rather than Russia's Proton.

However, with the Falcon Heavy yet to debut, it remains to be seen whether the Hawthorne, California-based company will be able to offer a reliable heavy-lift alternative to Proton and the Ariane 5.

Based on the medium-lift Falcon 9 v1.1, the Falcon Heavy will comprise a new first-stage core to be flanked by two side boosters, with the latter borrowed from the new first stage of the full-throttle Falcon 9 that SpaceX expects to debut this summer.

“We're building two types of cores and that's to make sure we don't have a bunch of different configurations of the vehicle around the factory,” Shotwell said in March. “I think it will streamline operations and really allow us to hit a cadence of one or two a month at every launch site we have.”

SpaceX has also had trouble meeting its Falcon 9 manifest. The company has quickly ramped up commercial and government missions of the rocket, which was recently certified by the U.S. Air Force to lift national security payloads, but over the past year technical issues and satellite-delivery delays resulted in the company executing six launches, rather than the 10 or 11 planned.

Some customers are eying back-up plans. Commercial fleet operator ViaSat says it will consider an alternative if it looks like the Falcon Heavy will be unable to deliver the mammoth ViaSat-2 Ka-band broadband communications satellite to orbit by late-summer next year.

In the meantime, Eutelsat is also still grappling with Proton delays. The company has already seen the launch of its Eutelsat 9B communications satellite postponed once by a Proton failures. Initially slated to launch in late 2014, the mission slipped to summer of this year following a catastrophic May 2014 launch accident that grounded the rocket for five months.

Of rocket's eight failures since 2010, most were attributed to Russian government missions, rather than the commercial launches managed by ILS on behalf of Proton prime contractor Khrunichev State Research and Production Space Center of Moscow. In addition, a number of the mishaps have been attributed to human error. However, the most recent Proton failure was an ILS-managed mission.

With Proton sidelined and Ariane 5 and Falcon 9 largely booked, new entrants to the commercial launch sector are seeing increased opportunities to compete. Japan's Mitsubishi Heavy Industries (MHI) recently won its first commercial satellite order with a contract to lift the Telstar 12 satellite atop an H-2A rocket in 2016 for Canadian operator Telesat. The company has pledged to halve launch costs to make the vehicle more competitive on the commercial market.