The world's first satellite successfully entered orbit!

The National Space Administration announced today that the world's first high-orbit synthetic aperture radar satellite, Land Exploration No. 4 01, has successfully entered its working orbit in recent days.

The Land Exploration No. 4 01 satellite was launched into space on August 13 at the Xichang Satellite Launch Center by a Long March 3B carrier rocket. Image source: China National Space Administration

According to Meng Lingjie, deputy chief designer of the Earth Observation and Data Center Project of the National Space Administration, the Land Exploration No. 4 01 satellite has undergone four orbit changes and has now accurately entered the predetermined orbit. The satellite is currently operating normally and in good condition, and will continue to carry out in-orbit testing and other work.

It is understood that this satellite is the world's first high-orbit synthetic aperture radar satellite. It uses an L-band synthetic aperture radar (SAR) payload and can provide a variety of observation modes. It is an important part of my country's space-based disaster observation system. It can conduct all-weather and all-day observations of my country and surrounding areas, and serve disaster prevention and mitigation, earthquake monitoring, land and resources surveys, as well as marine, water conservancy, meteorology, agriculture, environmental protection, forestry and other industry application needs.

What is the difference when looking at the Earth from a distance of nearly 40,000 kilometers?

In addition to using synthetic aperture radar technology, Land Exploration No. 4-01 is also known as the " highest synthetic aperture radar satellite in the world ". It operates in a very high orbit, nearly 40,000 kilometers from the earth. Satellites running on this orbit are like repeatedly drawing an "8" in the sky, which can conduct relatively continuous observations of a large area in a fixed manner, with a short observation revisit period and a wide imaging width.

Image source: CCTV News Client

It is reported that satellites operating in lower orbits of 500 or 700 kilometers generally stay in a certain area for about ten minutes. It will take several days for the next observation of the area, so the timeliness is relatively low. The Land Exploration No. 4 01 satellite flies higher and can see a larger area, making repeated observations of the same area more efficient.

By first having a macro and overall impression of the target over a large area and determining the area, low-orbit satellites can be used to conduct detailed observations at high resolution and in a small area, which can complement the functions of low-orbit satellites.

Comprehensive sources: National Space Administration, CCTV News, etc.