On March 1, 2002 (January 18, 2002 in the lunar calendar), the European giant earth environment monitoring satellite "Envisat" was sent into space. On March 1, 2002, the European giant earth environment monitoring satellite "Envisat" was successfully launched into space by an Ariane 5 rocket. "Envisat" has a net weight of 8111 kilograms, a height of 10 meters, a width of 26 meters, and a total cost of 1.5 billion euros. It is the largest, most expensive and most advanced earth environment observation satellite ever produced by the European Space Agency.