High-throughput communications satellite launched from China

A Long March 3B rocket lifts off Thursday from the Xichang space launch facility with the Apstar 6D communications satellite. Credit: Xinhua

A high-power broadband communications satellite designed to provide Internet access to airliner passengers, cruise ships, fishing vessels, and other mobile users successfully launched Thursday aboard a Chinese Long March 3B rocket.

The 12,235-pound (5,550-kilogram) Apstar 6D communications satellite lifted off at 1211 GMT (8:11 a.m. EDT; 8:11 p.m. Beijing time) Thursday from the Xichang space launch facility, located in Sichuan province in southwestern China.

A Long March 3B rocket carried the spacecraft aloft and headed toward the east-southeast from Xichang. The 184-foot-tall (56-meter) launch vehicle shed its four hydrazine-fed boosters and core stage in the first two-and-a-half minutes of the flight, followed by ignition of the Long March 3B’s second stage, and finally maneuvers using the rocket’s cryogenic upper stage to place the Apstar 6D satellite into orbit.

The Apstar 6D satellite deployed from the the Long March 3B’s third stage less than a half-hour after liftoff in an elliptical geostationary transfer orbit ranging between about 136 miles (220 kilometers) and 22,236 miles (25,790 kilometers) in altitude. The spacecraft’s own propulsion system will circularize its orbit at geostationary altitude over the equator in the coming weeks, where its velocity will match the speed of Earth’s rotation.

The spacecraft is owned by APT Mobile Satcom Ltd., a company headquartered Shenzhen, China, that was co-founded in 2016 by APT Satellite of Hong Kong and state-backed organizations in China.

APT Satellite said in a statement that the Apstar 6D spacecraft will “meet all types of mobile satellite communication, as well as satellite broadband connection needs in the Asia-Pacific region.”

The operator said that in the coming days the satellite will complete a second phase of the deployment of its power-generating solar arrays, and unfurl antennas to prepare for testing before entering commercial service.

Built by the China Academy of Space Technology, the Apstar 6D spacecraft is based on an enhanced version of China’s DFH-4 satellite platform, known as the DFH-4E. The satellite will use a conventional liquid-fueled engine to raise its orbit in the coming weeks, then rely on electric plasma thrusters to hold position in geostationary orbit during its planned 15-year mission.

APT Satellite procured the satellite and the launch through China Great Wall Industry Corp., or CGWIC, the government-owned company charged with selling Chinese spacecraft and launch services on the international market.

The Apstar 6D satellite is encapsulated inside the Long March 3B rocket’s payload fairing. Credit: CASC

Apstar 6D carries Ku-band and Ka-band communications payloads, including 90 Ku-band user beams to connect with customers and eight Ka-band gateway beams, according to CGWIC. The satellite will be positioned in geostationary orbit at 134 degrees east longitude, with a coverage area stretching from the eastern Indian Ocean to the western Pacific Ocean.

The spacecraft will serve Chinese airlines, maritime companies, and support emergency response and disaster relief agencies, officials said.

APT Satellite said the Apstar 6D satellite has a total throughput capacity of 50 gigabits per second, and has the ability to route more than 1 gigabit per second of data through a single beam. The satellite can generate up to 14.4 kilowatts of power.

APT Mobile Satcom Ltd. ordered the Apstar 6D satellite from the Chinese contractor in 2016. APT Mobile says the satellite is the first of up to four geostationary broadband satellites it plans to build and launch to create a global network, but the company has not announced firm contracts for follow-on spacecraft.

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