China achieves world-first with latest satellite launch

China has launched the world's first synthetic aperture radar satellite in high-altitude orbit, according to the China National Space Administration.

Dedicated to natural disaster prevention and mitigation, the remote sensing satellite, Land Surveyor 4A, was carried into orbit on a Long March 3B rocket that blasted off at 1:26 am on Aug. 13 from the Xichang Satellite Launch Center in Sichuan province. It soon entered its preset geosynchronous orbit, the administration said in a news release.

Remote sensing refers to the process of detecting and monitoring the physical characteristics of an area by measuring its reflected and emitted radiation at a distance, typically from aircraft or satellites.

Developed by the China Academy of Space Technology, the Land Surveyor 4A will extensively improve China's space-based disaster monitoring system, it noted.

The spacecraft is tasked with around-the-clock monitoring on Chinese territories and neighboring regions. In addition to disaster prevention and relief work, it will also be used in land and marine resources management, weather forecasting, environmental protection, and agricultural and forestry industries, the administration said.

Its users include the Ministry of Emergency Management, the Ministry of Natural Resources, the China Meteorological Administration and the Ministry of Agriculture and Rural Affairs.

Compared with other synthetic aperture radar satellites in low orbits and optical satellites, this type of satellite features better monitoring and imaging capabilities.

The satellite's designers explained that synthetic aperture radar can observe Earth and take pictures despite strong sunlight and thick clouds.

Current synthetic aperture radar satellites operate in low orbits, leading to problems such as limited scope and monitoring time per orbit.

By comparison, the same type of satellite traveling in high orbits can monitor a much larger area and will be more responsive to time-sensitive tasks such as obtaining images and data for disaster relief work, they said.

The space mission was China's 35th rocket launch this year and the 483rd flight of the Long March rocket family, the nation's main launch vehicle fleet.