27 years ago today, on March 26, 1998 (February 28, 1998 lunar calendar), our country successfully launched two American "Iridium". The picture shows the 50th launch of the Long March series of carrier rockets. At 1:01 am on March 26, 1998, Taiyuan Satellite Launch Center, our country developed and produced the "Long Erc" improved rocket successfully sent the two "Iridium" designed and manufactured by Motorola into the predetermined orbit. This launch is the 50th flight of the Long March series of carrier rockets, and it is also the second launch service of China Great Wall Industry Corporation to fulfill the "Iridium" launch contract. The "Long Erc" improved rocket used for launch is about 40 meters long, 3.35 meters in diameter, and has a take-off mass of 213 tons. It is based on the Long March II C rocket, adding a dispenser mainly used to send satellites from the initial berthing orbit to the final circular orbit and release two satellites at the same time. The "Iridium" system is a global satellite mobile communication system designed and manufactured by Motorola and operated by the "Iridium" company. It consists of 66 satellites in orbit and is deployed on six operating surfaces to achieve low-orbit small satellite communication.