China’s Long March 7 Rocket Successfully Launches Tianzhou 7 Cargo Spacecraft
The Long March 7 Y8 carrier rocket (referred to as “Long March 7 rocket” below) ignited and lifted off from the Wenchang Spacecraft Launch Site in Hainan at 22:27 on January 17, according to CCTV News. It precisely sent the Tianzhou 7 cargo spacecraft into its planned orbit, marking a successful start to China’s manned space mission in 2024. Since the arrival of the Shenzhou 14 crew on the Chinese space station on June 5, 2022, Chinese astronauts have been in continuous spaceflight for 591 days.
The Long March 7 rocket and Tianzhou 7 on January 17. Image from the News Center of the State Administration of Science, Technology, and Industry for National Defense
January 27, successful launch of Tianzhou 7. Screenshot from CCTV News broadcast
Cargo spacecraft launch frequency optimized to 3 times in 2 years
As one of the world’s most powerful cargo spacecraft, the Tianzhou series shuttles regularly between space and Earth, contributing continuously to the construction of the Chinese space station. “Tianzhou 7” is the second improved version of the “Tianzhou” series cargo spacecraft, with enhanced cargo space and carrying capacity. Its pressurized cargo hold has a volume of 22.5 cubic meters and a carrying capacity of 6.7 tons, with a total cargo loading capacity of 7.4 tons. With such strong capabilities, “Tianzhou 7” can support two manned spaceflight missions, Shenzhou 17 and Shenzhou 18, in a single cargo mission.
As reported by CCTV News, the seventh Tianzhou mission, which is the sixth cargo launch mission for the Chinese space station project, is the first mission for China’s manned space mission in 2024. It also marks the second cargo spacecraft for the Chinese space station’s application and development phase. Tianzhou 7 mainly carries three major categories of supplies, with a total of over 260 items weighing more than 5.6 tons. This time, the weight of fruits on Tianzhou 7 increased to about 90 kilograms, nearly 30 kilograms more than on Tianzhou 6. Furthermore, it brought a special Chinese New Year gift package for the astronauts. Starting from this mission, the launch frequency of the Tianzhou cargo spacecraft has been optimized from twice a year to three times in two years, further reducing the cost of space transportation.
Due to its sufficient carrying capacity, Tianzhou 7 also carries a popular science satellite, which will be deployed upon reaching its planned orbit.
January 27, the Long March 7 rocket and Tianzhou 7 launched into space. Screenshot from CCTV News broadcast
“Smart Rocket” precisely sends cargo spacecraft into orbit
According to the China Academy of Launch Vehicle Technology under China Aerospace Science and Technology Corporation (CALT), the Long March 7 rocket is a new generation medium-sized launch vehicle developed to meet the needs of the Chinese space station project. Its low Earth orbit carrying capacity reaches 14 tons. This latest launch marks the seventh collaboration between the Long March 7 rocket and the Tianzhou cargo spacecraft for space missions.
Zhou Ning, a member of the Long March 7 rocket launch team from CALT, stated that they continuously optimize the rocket’s systems, mission procedures, and the scale of the testing and launch team, following the principle of “better with every launch.” Currently, the comprehensive performance of the rocket’s systems continues to improve, and the launch cycle has been reduced from the initial 38 days to the current 25 days.
At Wenchang Launch Site, the launch tower is only about one kilometer away from the sea. In order to enhance its capability to cope with humid conditions, for the first time in this mission, the Long March 7 rocket attempted to cover the fairing with a lightweight cover after it was transported to the launch tower, in an effort to isolate the rocket body from the “high temperature, high humidity, and high salt mist” external environment as much as possible. Furthermore, to reduce the load on the fairing after the rocket launches, and to enhance the rocket’s reliability, the Long March 7 launch team added more ventilation holes to the fairing.
Zhou Ning explained, “The control logic of this Long March 7 rocket is more rigorous, allowing it to respond more calmly to any sudden situations that may arise just before the launch.” The rocket’s propellant temperature and quantity are controlled with high precision. In order to ensure precise orbit insertion, the Long March 7 rocket continuously corrects the trajectory design based on deviations from previous missions. In addition, the “navigation function” of the rocket is becoming more intelligent through iterative guidance control, enabling the second-stage rocket to make real-time course corrections according to actual conditions, and deliver the cargo spacecraft to its designated location. In order to meet the needs of the space station missions, the Long March 7 rocket is also capable of launching twice within a three-month period. Currently, the Long March 7 rocket scheduled for the next Tianzhou launch mission has been fully assembled and will be able to meet the demand for launching missions in the short term.
Shao Yetao, another member of the Long March 7 rocket launch team from CALT, mentioned that they are currently working on the development of a 5.2-meter fairing, which will broaden the payload adaptability and fully leverage the rocket’s capacity to create more value. Research and development efforts will also focus on enhancing the rocket’s fault tolerance, making the Long March 7 rocket a “smart rocket” with diagnostic capabilities.
According to CALT, in the coming years, the Long March 7 rocket will continue to carry out space station cargo spacecraft launch missions, providing logistical support for the normal operation of the Chinese space station with a launch frequency of 1-2 times per year. In addition, leveraging its high precision, good stability, and strong carrying capacity, the Long March 7 rocket will collaborate with a wider range of payloads for space exploration.