Shijian-13, aka ChinaSat-16, the nation's first high-throughput communication satellite, is seen in its final assembly prior to its launch in 2017. Photo: China Academy of Space Technology
Shijian-13, aka ChinaSat-16, the nation's first high-throughput communication satellite, is seen in its final assembly prior to its launch in 2017. Photo: China Academy of Space Technology

China’s first high-throughput communication satellite, Shijian-13 (Practice-13), is up and running in space after accomplishing an inauguratory two-way 5Gbps (gigabits per second) laser-communication test with its ground control center, the China National Space Administration said on Tuesday.

The satellite, also known as ChinaSat-16, was shot into geostationary orbit more than 35,000 kilometers above the surface of the Earth atop a Chang Zheng (Long March) rocket from the Xichang Satellite Launch Center in southwestern China’s Sichuan province last April.

Chinese orbital carrier rocket Long March 3B launched Shijian-13 into geostationary orbit in April 2017. Photo: Xinhua

It was made by the state-owned China Aerospace Science and Technology Corporation as the best of what China’s aerospace industry has to offer in the global competition to upshift the capacity of radio communication services and lower cost-per-bit.

The satellite’s ground control center in Beijing said in a statement that Shijian-13 would start amplifying and relaying signals between base stations in remote areas for distance education, emergency communication and disaster relief.

Shijian-13 has a transfer capacity of 20Gbps – more than that of all previous Chinese communication satellites combined – and a designed orbital life of 15 years. Airborne and shipborne Internet access via the satellite can be guaranteed a mean download speed of 150 megabits per second and 12Mbps for upload.

An animation of Shijian-13 in orbit. Photo: China Central Television

China plans to launch several more similar satellites before 2020, knotting together a constellation of devices with a combined transfer capacity of 200Gbps that will encompass not only China but the rest of the Asia-Pacific region.

On the ground, meanwhile, a nationwide investment boom for base stations is working in tandem, Xinhua reports, to install more satellite dishes along the borders, on frigid plateaus in Tibet, and on newly reclaimed islands and airstrips in the South China Sea.

Analysts suspect that each communication satellite to be launched may also contain optical imaging or synthetic aperture radar sensors so they can can spy on military installations of neighboring armies and even detect low-observable aircraft from space.

The South China Morning Post late last year reported that Chinese scientists at multiple institutions were making headway toward putting “ghost imaging” technology on a satellite.

A satellite dish in northwestern China’s Xinjiang region. Photo: Sunkins/Wikimedia

Gong Wenlin, director of research at the Quantum Optics lab at the Chinese Academy of Sciences in Shanghai, said he expected his team to build a prototype by 2020.

One key goal is to develop optical cameras that can see through clouds, smoke, dust, and other obscuring particles. This is a particular issue for electro-optical imaging, where overcast and other environmental factors can easily blur or block the view.

The virtue of integrating “ghost imaging” modules into a communication satellite is more precise positioning of a targeted object, even if the object itself doesn’t emit signals or its signal is erupted, as constant ground-space transmission of signals between the satellite and any ground communication point close to the target can help pinpoint its location.

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