Proton failure to delay Inmarsat Global Xpress roll-out

Inmarsat control room: The company provides mobile communications via satellite

The completion of the UK's biggest commercial space project is facing several months of delay.

Inmarsat of London has confirmed that the roll-out of its new Global Xpress satellite network is on hold while Russia probes the latest failure of a Proton rocket.

Six Protons and their payloads have now been lost in the past five years.

Inmarsat's third GX satellite was due to be the next customer in line, but this flight has now been postponed.

The company says it will wait until it hears the results of a Failure Review Oversight Board before making any decisions on what to do.

Rupert Pearce, Inmarsat's CEO, commented: "This incident involving a failed Proton launch from the Baikonur Cosmodrome is extremely unfortunate and will inevitably delay our launch plans for our third Global Xpress satellite.

"This is the third time our Global Xpress programme has suffered launch delays because of Proton launch failures.

The I-5s are among the biggest commercial telecoms satellites in operation today

"Although in the past, Proton has returned to flight within a few months of a launch failure, it will not be possible to determine the length of the delay in the launch of I-5 F3 until the cause of the [latest] launch failure is established."

Inmarsat is the world's largest mobile satellite services operator.

Its GX network, which requires a minimum of three satellites in orbit to provide global coverage, is costing more than $1.6bn (£1bn) to build and launch, and should enhance communications for ships, planes, the armed forces and broadcasting companies.

Two I-5 spacecraft were launched successfully on Protons - in December 2013 and February 2015. The third spacecraft was waiting in Baiknour, poised to ride its Proton to orbit next month.

Fortunately for Inmarsat, it is able to make use of the pair already in space, and, indeed, in recent weeks, broadcasters in particular have been doing just that. They have been beaming news reports from the Nepal earthquakes through the I-5 F1 that is positioned over Europe and Asia.

Inmarsat has exercised an option for a fourth I-5 satellite from manufacturer Boeing. This is intended as a spare but will likely be used where the market for GX services is strongest - assuming the first three satellites are also all in orbit and working.

"We are reassured that I-5 F4 is currently under construction by Boeing in California, and remains on schedule for completion in mid-2016, with a potential SpaceX launch in the second half of 2016, providing us with significant mission assurance in the case of any protracted delays in Proton's return to flight, or a failed launch of I-5 F3," said Mr Pearce.

Given the size of the I-5s, at over six tonnes, one of SpaceX's forthcoming Falcon-Heavy vehicles would most probably be needed to loft the Inmarsat platform. The American rocket company is due to test this vehicle later this year.

The Proton Breeze M rocket that failed on Saturday was carrying the Mexsat 1, or Centenario, satellite, intended to provide communications services over Central America.

Preliminary flight data indicated that an anomaly occurred in the rocket's third stage approximately 490 seconds after lift-off, at an altitude of about 160km.

The rocket and its satellite passenger are thought to have burnt up on re-entry into the Earth's atmosphere.

Proton rockets have had an alarming number of failures in recent years

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