On this day, 28 years ago, on December 8, 1997 (November 9, 1997 in the lunar calendar), the Chang2C modified rocket successfully launched Iridium satellites for the first time. The improved "Long March 2C" carrier rocket developed by my country was launched at the Taiyuan Satellite Launch Center. At 3:16:49:5 pm on December 8, 1997, my country's self-developed improved "Chang-2C" launch vehicle was launched into space at the Taiyuan Satellite Launch Center, successfully launching two Iridium satellites manufactured by Motorola in the United States. The satellite was sent into a predetermined orbit. This is the first commercial launch of the Iridium satellite launch contract undertaken by China Great Wall Industry Corporation, and it is also the 49th launch of the Long March series of launch vehicles. The improved "Chang-2C" rocket used for launch has a total length of about 40 meters, a maximum diameter of 3.35 meters, and a take-off mass of 213 tons. About 50 minutes after the rocket flew, the distributor successfully changed its orbit, releasing two Iridium satellites in a near-Earth circular orbit with a perigee of 629 kilometers, an apogee of 632 kilometers, and an inclination angle of 86.3 degrees. The Iridium satellite system is a global satellite personal communication system designed by Motorola, Inc. of the United States. It consists of 66 satellites. It is deployed on six operating surfaces in an orbit at an altitude of about 700 kilometers from the earth to realize low-orbit small satellite communications. China Great Wall Industry Corporation and Motorola of the United States signed a launch contract in April 1993. After this launch, ten more launches will be carried out in recent years, using one rocket and two stars to launch another 20 Iridium satellites that have been networked and replenished into orbit. The US Delta and Russian Proton rockets also undertook the launch of Iridium systems respectively. This launch is the first international commercial launch carried out by the Taiyuan Satellite Launch Center. After 30 years of construction, this center has the ability to launch various types of polar orbiting satellites, and has successfully launched two "Fengyun-1" satellites into space.