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ILS unveils two Proton variants sized for smaller satellites

The Proton Medium is designed to haul 5 metric tons to geostationary transfer orbit; the Proton Light is designed to haul 3.5 metric tons — performance comparable to a recoverable SpaceX Falcon 9 rocket. Credit: ILS graphic

This story was updated at 11:37 a.m. Eastern

PARIS — International Launch Services on Sept. 13 announced two new variants of its Proton rocket that will be sized to launch smaller geostationary satellites.

The Proton Medium and Proton Light, which ILS officials said Krunichev has been quietly developing for Reston, Virginia-based ILS for more than a year, are on track to debut in 2018 and 2019, respectively.

The Proton Medium and Proton Light are both two-stage rockets featuring the same Breeze M upper stage as the three-stage Proton Breeze M rocket.

In addition to dispensing with the second stage, both the Proton Medium and Proton Light feature minor lengthening of the remaining two booster stages.

The Proton Medium is designed to haul 5 metric tons to geostationary transfer orbit; the Proton Light is designed to haul 3.5 metric tons — performance comparable to a recoverable SpaceX Falcon 9 rocket. All three Proton variants will launch from the Baikonur Cosmodrome in Kazakhstan.

ILS graphic
ILS graphic

ILS President Kirk Pysher told reporters attending a breakfast at Eurconsult’s World Satellite Business Week Conference here, that ILS has no plans to introduce a reusable rocket. “We are very proud of the fact that we launch an expendable launch vehicle,” he said.

Pysher said the Proton Medium and Light variants were designed to address market demand for lighter satellites such as those that rely on all-electric propulsion to slowly make their way to geostationary orbit from their transfer orbit drop-off point.

“These vehicles are the right size for [customers’] current plans,” Pysher said. “We believe this is the right solution for Proton to be viable for at least the next 15 years,” Pysher said.

During a panel discussion later the same day, Pysher said ILS believes that electric-propulsion satellites comprise 40 percent of Proton’s addressable market.

Andrey Kalinovskiy, director general of Krunichev State Research and Space Production Center — the Russian entity that builds Proton and own ILS — said in a statement that that Proton Medium and Proton Light variants are being designed for ILS and the commercial market it serves — not for the Russian government, a heavy user of the Proton Breeze M.

“Since the new product line is essentially an offspring of Proton M, Krunichev is able to optimize production and operational efficiencies and transfer those savings [onto] the customers,” Kalinovskiy said.

ILS did not disclose pricing but said in a statement that the Proton Medium and Light “will be highly competitive with all comparable vehicles including SpaceX and Ariane.”

As development of the Proton Medium and Proton Light proceeds, ILS continues to market the more powerful Proton Breeze M — including to SpaceX customers facing an uncertain wait following the Sept. 1 pre-flight explosion that destroyed a Falcon 9 and its Amos-6 payload two days before scheduled liftoff.

Jim Kramer, ILS vice president of engineering and mission assurance, said ILS has a Proton Breeze M available in 2017 “if somebody wants or needs a launch.”

“We do have capability to help out those customers that are in dire straits today,” Pysher added, noting the the typical 18 months from contract to launch can be reduced to nine months for payloads that have flown Proton before.

SpaceX President Gwynne Shotwell, speaking on the same Sept. 13 panel here as Pysher, said a November return to flight is SpaceX’s best hope, noting the company still hasn’t isolated the cause of the explosion, or determined whether it originated with ground support equipment or the rocket.

Proton hasn’t flown since early June when an underperformance issue marred an otherwise successful launch of Intelsat’s Intelsat-31 satellite into geostationary transfer orbit. Proton is expected to remain grounded until at least mid November.

SpaceNews Paris Bureau Chief Peter B. de Selding contributed to this story.

Brian Berger is editor in chief of and the SpaceNews magazine. He joined in 1998, spending his first decade with the publication covering NASA. His reporting on the 2003 Space Shuttle Columbia accident was...