Triple liftoff: Long March rockets set a record

China Aerospace Science and Technology Corp, the country's dominant State-owned space contractor, conducted three launches of its Long March rocket family on Tuesday, marking the first time China has carried out three space missions in a single day.

The first launch occurred at 6:11 am, when a Long March 6A carrier rocket lifted off from the Taiyuan Satellite Launch Center in Shanxi province and deployed a group of internet satellites into orbit.

The satellites were designed and built by the China Academy of Space Technology, a CASC subsidiary based in Beijing. They are part of China's State-run mega internet satellite network, which had more than 110 satellites in orbit before the latest deployment.

The Long March 6A, a medium-lift launch vehicle developed by the Shanghai Academy of Spaceflight Technology, another CASC subsidiary, consists of a 50-meter liquid-propelled core booster and four solid-fuel side boosters. The rocket has a liftoff weight of 530 metric tons and is capable of transporting satellites to multiple types of orbit, including sun-synchronous, low-Earth and intermediate circular orbits.

Five-and-a-half hours later, a Long March 4B rocket blasted off from the Jiuquan Satellite Launch Center in the Inner Mongolia autonomous region, sending the Yaogan 47 satellite into space.

Also built by the China Academy of Space Technology, the satellite will be used to survey land resources, map urban areas, monitor agricultural yields and support environmental protection and disaster prevention and mitigation.

Like the Long March 6A, the Long March 4B was developed by the Shanghai Academy of Spaceflight Technology. It can deliver multiple satellites with a combined weight of up to 2.5 tons to a typical sun-synchronous orbit at an altitude of 700 kilometers.

At 11:08 pm, a Long March 3B rocket lifted off from the Xichang Satellite Launch Center in Sichuan province, placing an experimental satellite, Communication Technology Demonstrator 22, into orbit.

The satellite, also developed by the Shanghai academy, will be used to transmit communication signals and data, relay radio and television programs, and conduct technological tests.

The Long March 3B, developed by the China Academy of Launch Vehicle Technology, another CASC subsidiary, is one of China's most frequently used rocket models and has a strong operational record. It is primarily used to place satellites into geostationary transfer orbit and can carry payloads of up to 5.5 tons. The rocket can also send spacecraft to medium-Earth orbit and lunar transfer orbit.

Pang Zhihao, a spaceflight technology expert and veteran space writer, said executing three launches in a single day requires extensive experience and coordination.

"Launching a rocket involves far more than the rocket and its service tower," Pang said. "It requires support facilities and personnel across the country, including tracking and telemetry stations and satellite control centers. Mission planners must make detailed and careful arrangements to coordinate infrastructure and specialized teams."

zhaolei@chinadaily.com.cn