China successfully launches its Gaofen-3 Earth-observing satellite
China continues its busy 2016 launch schedule with the latest liftoff of the country’s high-resolution Earth-imaging satellite, known as Gaofen-3. The spacecraft was sent aloft atop a Long March 4C rocket at 6:55 p.m. EDT (22:55 GMT) Tuesday, August 9, from the Taiyuan Satellite Launch Center in Shanxi Province.
The launch marks the 11th out of more than 20 orbital missions planned to be conducted by China before year-end. Tuesday’s liftoff comes just four days after the country sent its Tiantong-1 No. 1 communications satellite into space. As was the case with the Aug. 5 launch, Gaofen-3 was also blasted off unannounced.
The Long March 4C rocket lifted off from the Launch Complex 9 at Taiyuan to start its short vertical ascent before it turned southwest. No information about the mission’s flight schedule was released by Chinese media. However, the Long March 4C’s usual mission profile includes a 15-minute flight ending in spacecraft separation.
According to USSTRATCOM, the Gaofen-3 satellite was inserted into a low-Earth orbit (LEO) at an altitude of 457 by 464 miles (735 by 747 kilometers), inclined 98.41 degrees.
Developed by the China Academy of Space Technology (CAST), Gaofen-3 (meaning high-resolution in Chinese) is based on the CS-L3000B platform. The satellite features two deployable solar arrays and is equipped with a multi-polarized C-band Synthetic Aperture Radar (SAR), enabling all-day, all-weather imaging at meter-level resolution.
According to Chinese media reports, Gaofen-3 will be used for disaster warning, weather forecasting, water resource assessments, and the protection of maritime rights. The satellite will be mainly used by the country’s State Oceanic Administration.
“It will play an important role in monitoring the marine environment, and islands and reefs, as well as ships and oil rigs,” said Xu Fuxiang, head of the Gaofen-3 project at CAST.
However, what is typical for China’s surprise launches, it is possible that the new spacecraft could be utilized as a spy satellite. Gaofen-3 is the country’s first low-orbit remote sensing satellite and its capability of snapping the pictures of Earth 24 hours a day in all weather conditions at a resolution down to approximately one meter makes it a perfect surveillance tool.
Xinhua press agency reported Gaofen-3 is able to provide high-definition remote sensing data over long periods of time as it can capture continuous imaging for nearly one hour during ocean observation. The agency underlined the new spacecraft is also capable of providing clear images of all roads, buildings, and boats. The satellite is expected to deliver all its services for up to eight years.
Gaofen satellites are part of the China High-Resolution Earth Observation System (CHEOS) initiated in 2010. The system plans to provide real-time, all-day global Earth observation in any weather for disaster prevention and relief, climate change monitoring, geographical mapping, as well as environmental and resource surveying. The first Gaofen satellite was launched in April 2013.
The CHEOS program comprises the elements of the space-borne system, the near-space system, aerial system, the ground system, and application system as a whole to realize Earth observation at high temporal, spatial, and spectral resolution.
Next spacecraft in the series, Gaofen-5, is currently scheduled to be launched in 2017. By 2020, it is hoped the entire seven-satellite CHEOS system will be in orbit. The primary data users of the program are the Ministry of Land and Resources, the Ministry of Environmental Protection, and the Ministry of Agriculture.
The Long March 4C booster employed for Tuesday’s launch has a liftoff mass of an estimated 250 metric tons and is 150 feet (54.7 meters) in length with a diameter of 11 feet (3.4 meters). It is capable of delivering payloads of up to 4.2 metric tons to LEO, 2.8 metric tons to a Sun-synchronous orbit, and up to 1.5 metric tons into a geostationary transfer orbit.
Tuesday’s launch marked the 233rd flight of the Long March rocket. The next Chinese mission is currently scheduled for sometime this month (August) and will involve a Long March 2D booster. That rocket is slated to send the QUantum Experiments at Space Scale (QUESS) technology demonstrator into orbit from the Jiuquan Satellite Launch Center. However, the exact date of the launch has yet to be announced.
In late 2016, China plans to return to human space flight. Shenzhou-11, a planned crewed mission, is slated to lift off from Jiuquan and dock with China’s upcoming second space lab, Tiangong-2, which should be in orbit by the time the crew’s Shenzhou spacecraft is sent aloft. The exact launch dates for these missions have yet to be released.
Video courtesy of CCTV+
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