Intelsat’s IS-33 satellite customer set includes aeronautical and maritime mobile communications service providers that can adapt to a satellite without north-south stationkeeping. But classic fixed telecommunications services are another story. Credit: Intelsat

UPDATE: Intelsat said many people concluded from this article that a fresh anomaly had occurred aboard IS-33e since Intelsat filed its insurance claim, and that customers might see degraded service as a result. The second anomaly, reported here, was fully integrated into Intelsat’s claim, and there is no effect on the satellite’s performance — only its anticipated service life. Here is a Q&A with Intelsat that deals with the issue:

PARIS — The Intelsat IS-33 satellite launched in August 2016, which took longer than expected to enter service because of a malfunction of its primary thruster engine, has suffered a second and potentially more serious anomaly, industry officials said.

The latest failure, which officials said has yet to be fully diagnosed, has resulted in an unusually large amount of propellant used during the satellite’s routine position-maintenance operations.

Specifically, IS-33 is using up more fuel than it should when it undertakes north-south stationkeeping maneuvers, which geostationary-orbit satellites conduct throughout their lives to keep themselves fully visible to fixed ground stations.

Industry officials said that while insurance underwriters have agreed to pay Intelsat’s claim for the thruster issue, some of them are hesitating to pay the claim as it results to the excess-fuel-use issue.

Not all underwriters accept Intelsat’s claim yet

Intelsat has filed a claim totaling $78 million to cover both problems and has begun to receive payment from underwriters. But several insurers are holding off payment until they get more information.

One industry official said the problem is that manufacturer Boeing Satellite Systems International has not produced a definitive failure analysis on either problem despite the passage of a year.

Intelsat 33e’s thruster failure slowed the satellite’s climb to circular geostationary orbit after the August 2016 launch. Instead of starting commercial service at 60 degrees east, with a broad footprint over Europe, the Middle East, Africa, the Asia-Pacific and the Indian Ocean, commercial service began in late January.

Intelsat officials had said that the thruster failure had depleted the satellite’s store of on-board propellant, but not by much, and that any reduction in the planned 15-plus years of service life would be minimal.

Those calculations have now been sidelined with the latest problem.

Boeing declined to discuss the IS-33 issue.

Dianne J. VanBeber, Intelsat vice president for investor relations and communications, confirmed the attitude-control problem, and in a statement said Boeing had yet to determine a root cause for either problem.

“Intelsat’s insurance claim for Intelsat 33e covers two performance elements. The first has to do with a malfunction in the primary thruster that is used for orbit raising. The second has to do with a larger-than-expected propellant required to control the satellite attitude during the north/south station keeping maneuvers. With respect to cause, there has been intensive, exhaustive technical investigation, but identification of cause is still incomplete.

Discussions with the satellite’s insurers continue per our expectations,” Intelsat’s statement said.

Intelsat a key customer for satellite insurers

Intelsat is one of the satellite insurance industry’s biggest customers. At a time when satellite insurance is plentiful and historically inexpensive, underwriters’ tendency is to want to curry favor with clients of this size.

The fact that several have declined, so far, to pay Intelsat’s full claim is therefore unusual. One industry official said insurers are waiting for more information on the extent of the fuel depletion and its cause.

IS-33 is the second of seven Intelsat Epic HTS, or high-throughput, satellites. The first, IS-29e, was launched in January 2016. Three more — IS-32e, IS-33e and IS-35e — were launched between February and July of this year.

The fifth Epic, IS-37e, is scheduled for launch Sept. 5 on a European Ariane 5 rocket. All but IS-32e are Boeing 702 models. None of the others launched so far has shown issues with the thrusters.

Telecommunications satellite operators often stop maintaining their spacecraft on their north-south axis late in their service lives to preserve fuel and provide for additional years of operations.

The resulting orbit traces a figure-8 maneuver that makes services to fixed Earth antennas challenging but is fine for many mobility customers with antennas that track a satellite’s location.

IS-33e’s customer set includes aeronautical connectivity customers Gogo, Panasonic Avionics and Global Eagle Entertainment, as well as maritime connectivity service providers Speedcast and Marlink.

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Peter B. de Selding
Peter B. de Selding

Peter de Selding is a Co-Founder and editor for He started SpaceIntelReport in 2017 after 26 years as the Paris Bureau Chief for SpaceNews where he covered the commercial satellite, launch and the international space businesses. He is widely considered the preeminent reporter in the space industry and is a must read for space executives. Follow Peter @pbdes

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