PARIS — Satellite fleet operator SES, in a direct challenge to competitors ViaSat, Eutelsat and Inmarsat, is investing $500 million in a large, all-Ka-band spot beam high-throughput satellite to launch over the Americas in 2020 for aeronautical connectivity and other mobility applications, industry officials said.

Luxembourg-based SES has secured a long-term contract from in-flight entertainment provider Thales Avionics, which will commercialize its FlytLIVE service starting in 2017 using two existing SES satellite before the tailor-made spacecraft, called SES-17, is launched in 2020.

SES and Thales are expected to announce their agreement on Sept. 12 at the World Satellite Business Week conference here, organized by Euroconsult.

Industry officials said SES’s total investment in the system is around $500 million, including the satellite, its launch, the network of ground gateways and insurance.

SES has been hinting for months that it was seeking ways to combine the strengths of its O3b medium-Earth-orbit constellation of high-throughput satellites with the company’s existing fleet of geostationary-orbit satellites.

SES-17 will be built by Thales Alenia Space of France and Italy, which is prime contractor for the 12 existing O3b satellites. The company is under contract for another eight O3b spacecraft.

Officials said SES-17, using all-electric propulsion, will generate 15 kilowatts of power to the payload of 200 Ka-band spot beams at the end of its 15-year service life.

Adding U.S.-based Thales Avionics gives SES the fourth large in-flight-connectivity/entertainment provider. Thales Avionics competitors Gogo, Global Eagle Entertainment and Panasonic Avionics are already large SES customers for Ku-band capacity.

Competitors ViaSat Inc. and Eutelsat are partnering to offer airlines connectivity in the North Atlantic and European air routes, and ViaSat has announced a three-satellite ViaSat-3 constellation for global coverage for 2019. Two of those satellites are under construction.

London-based Inmarsat’s Global Xpress Ka-band broadband capacity is in service through three satellites in geostationary orbit, and Inmarsat is building out an air-to-ground network in Europe to handle demand that is considered too great in that region’s crowded airspace to be handled by satellites alone.

Satellite fleet operator Intelsat, which like SES operates a 50-satellite fleet worldwide, has up to now shared SES’s preference for Ku- rather than Ka-band for high-throughput satellites and is a minor shareholder in the planned OneWeb network of hundreds of satellites in low Earth orbit scheduled to launch by the end of this decade.

SES-17 represents SES’s first all-Ka-band satellite in geostationary orbit. In addition to airline passenger connectivity, the satellite is expected to provide bandwidth for what some officials say to could be an even greater market: the connected aircraft for cockpit and aircraft-maintenance services.

A Boeing 787 aircraft generates more than 30 terabytes of data per month of flying. Airlines are gradually moving from heavy physical flight bags to electronic flight bags.

Industry estimates of how much revenue this could provide to the service providers — fleet operators like SES and the direct airline suppliers like Thales Avionics, Gogo, Global Eagle and Panasonic Avionics.

By some estimates, average annual revenue per commercial aircraft from in-flight connectivity could more than double, to $300,000 per plane, within five years.

Peter B. de Selding was the Paris bureau chief for SpaceNews.