On December 21, 2000 (November 26, 2000 in the lunar calendar), the second "Beidou Navigation Test Satellite" was launched in Xichang. The picture shows the launch site. On December 21, 2000, the last launch of China's aerospace industry in this century was a complete success. China astronauts bid farewell to the 20th century with outstanding results in 5 battles and 5 victories throughout the year. At 0:20 on the 21st, my country's second self-developed "Beidou Navigation Test Satellite" was launched into space with a "Long March 3A" rocket at the Xichang Satellite Launch Center and accurately entered the predetermined orbit. Together with the first "Beidou Navigation Test Satellite" launched on October 31 of the same year, it constitutes the "Beidou Navigation System". This means that my country will have the first generation of satellite navigation and positioning system independently developed. The person in charge of relevant departments introduced that my country's independently established first-generation satellite navigation and positioning system-the "Beidou Navigation System"-can meet domestic satellite navigation needs. This system is a regional navigation system that provides satellite navigation information all-weather and all-day. When completed, it will mainly provide navigation services in highway transportation, railway transportation, maritime operations and other fields, and will play a positive role in promoting my country's economic construction. A satellite navigation system is formed by using several navigation and positioning satellites, which combines the advantages of traditional astronomical navigation and positioning and terrestrial radio navigation and positioning, and is equivalent to a radio navigation station set up in space. It can determine the geographical latitude, longitude and altitude for users at any time and anywhere. At present, only a few developed countries in the world have the ability to independently build satellite navigation systems. The "Beidou Navigation Test Satellite" and the "Long March 3A" carrier rocket were developed by the Space Technology Research Institute and the Launch Vehicle Technology Research Institute affiliated to the Aerospace Science and Technology Group. This launch is the 64th flight of my country's Long March series of launch vehicles. It is also the 22nd consecutive successful space launch since October 1996. Computer images of three satellites in the Galileo Global Satellite Navigation System