China continues to establish new milestones in space. In recent years, the China National Space Agency (CNSA) has begun assembling the Long March-9 (CZ-9), the country’s first reusable super-heavy launch vehicle; the Tianwen-1 mission became the first Chinese orbiter, lander, and rover combination to reach Mars, and their super-secret spaceplane completed its second flight (after spending 276 days in space). China has also made significant progress in terms of human spaceflight, especially where the Tiangong space station is concerned.
Earlier this week (Tues. May 30th), the China Manned Space Agency (CMSA) took another major step when it launched the country’s sixteenth mission (Shenzou-16) to Tiangong atop a Long March-2F (CZ-2F) rocket. This mission delivered three taikonauts to the space station and performed the most complicated docking maneuver ever attempted. The mission highlights included successfully testing the Shenzou’s upgraded instruments and systems, which allowed the spacecraft to autonomously rendezvous with the station under less-than-ideal conditions.
The Shenzou-16 spacecraft carried Jing Haipeng and Zhu Yangzhou, both members of the People’s Liberation Army Astronaut Corps (PLAAC), and Gui Haichao, a payload specialist and professor at Beihang University. The spacecraft docked with the space station at 4:29 am Beijing Time on May 30th (01:29 pm PDT; 04:29 pm EDT on Monday, May 29th). The autonomous fast docking process, the most complicated one to date for the CMSA, took about six and a half hours and consisted of six autonomous orbit adjustments.
During the maneuver, the space station was blocking too much sunlight, making it more difficult to determine the dock’s position. As Yao Jian, the managing designer of the docking subsystem, shared via the state-owned television network CGTN, Shenzou’s new light sensors and other upgraded systems compensated for this and assisted with the complicated maneuver:
“This is the first time we performed radial docking after the T-shaped station was assembled,” he said. “We had to add new dampers to reduce the impact on both the spaceship and the station.” Zhang Yi, the deputy managing designer of Shenzhou-16‘s navigation and control systems, added, “The new sensors have improved abilities to recognize targets. They can tell if an object is the target or just an obstacle blocking the way.”
Even with the upgraded systems, the CMSA had several measures and a backup plan in place. This included the multiple navigation systems that ensure the spaceship knows precisely where the dock is. Said Shao Limin, deputy manager of technologies of the Shenzhou-16:
“If the rocket fails, the automatic escape system in the spaceship will be activated and bring the taikonauts back to the ground safely. We can also use emergency returning if the spaceship is breached. We have two systems for positioning: the BeiDou satellites and microwave radars. The BeiDou system has a machine-A and a machine-B that are hot backups of each other – if one breaks, the other can go on working. We can switch to manual docking and ask the taikonauts to finish the process. The two processes are completely independent of each other.”
In addition to the upgraded spacecraft, the Long March-2F (code-named Y16) that provided launch services also had numerous upgrades. This rocket, also known as the Shenjian (“Divine Arrow”), is currently China’s only crewed launch vehicle and will remain as such until the debut of the Long March-9. In fact, the Y16 underwent 20 improvements for the mission, while a second rocket (the Y17) was prepped and ready as a backup launch vehicle. Chang Wuquan, the rocket’s chief designer at the China Academy of Launch Vehicle Technology (CALVT), explained in a separate CGTN news release:
“For example, for rocket flights, the separation at all stages s critical. So, we carried out an improved design over the redundancy of the solid rocket ignition link. This is to further improve the reliability of the separation of boosters, as well as the ship and the rocket. The Y17 has completed emergency rescue state setting. After the launch of the Y16, it will carry out emergency rescue duty for up to six months and complete the normal launch mission in the second half of the year as per the plan.”
The Long March-2F made its debut launch in 1999 and sent China’s first taikonaut into space by 2003. The rocket will continue to be the workhorse of the CMSA as the Tiangong space station continues to evolve and additional modules are added. According to a statement by the CMSA last year, the Tiangong space station is likely to be expanded from three to six modules, with improved versions of the existing Tianhe, Wentian, and Mengtian modules. There are also plans to incorporate the Chinese Survey Space Telescope (CSST) – aka. Xuntian (“sky survey”) – which is expected to launch by 2024.
According to Wang Xiang, commander of the space station system at the China Academy of Space Technology (CAST), the addition of a new core module is also being considered. “Following our current design, we can continue to launch an extension module to dock with the forward section of the space station, and the extension module can carry a new hub for docking with the subsequent space vehicles,” he said in an interview with the state-owned media company CCTV.
Completing the super-heavy Long March-9 vehicle is vital to the Chinese Lunar Exploration Program (CLEP, aka. Chang’e) and the China Manned Space Program (CMSP). Lin Xiqiang, the deputy director of the CMSA, recently announced that this program will send the first taikonauts to the Moon by 2030. Coinciding with more robotic missions, the long-term goal of these programs is to establish the International Lunar Research Station (ILRS) around the South Pole-Aitken Basin. This station will be a direct competitor to NASA’s Artemis Program and its related infrastructure.