Technological development and innovation are essential for the success of China's space program, said a deputy to the ongoing first session of the 14th National People's Congress (NPC) on Tuesday.
Sun Zezhou, also the chief designer of Chang'e-4 probe, reviewed China's achievements in space exploration at a group interview before the second plenary meeting of the first session of the 14th NPC in Beijing, noting the achievements were made through down-to-earth endeavor and persistent innovation.
"Chang'e-3 made breakthroughs in autonomous obstacle avoidance and lunar night survival technologies. Since then, the lunar landing is no longer a blind landing, and the probe can work on the lunar surface for a longer time and obtain more scientific exploration data. Chang'e-3 has been on the moon for nine years, making it the world's longest-serving spacecraft. In 2018, we placed a relay satellite at the Earth-Moon Lagrange L2 point of the Earth-Moon connection, because it is possible to see the far side of the moon and the Earth at the same time, establishing a relay communication link between the two. Chang'e-4 successfully landed on the far side of the moon with the support of the relay satellite and conducted a roving probe, the first of its kind in the world. As we all know, the far side of the moon is a virgin land that cannot be directly observed on the Earth. Chang'e-4 conducted a close and detailed exploration on the far side of the moon for the first time, which enriched human's scientific understanding of the moon," said Sun.
Sun said that in 2021, for the first time in the world, Tianwen-1 completed flyby, landed and roved Mars in a single mission, while in other countries, the missions were achieved in separate tasks. He said China's leapfrog development is based on both its scientific and technological strength and the courage to take the lead.
"Mars has a thin atmosphere, so landing on Mars first faces the problem of aerodynamic and thermal conditions in the atmosphere. By leveraging the re-entry experience on the Earth, we accumulated data by selecting a method suitable for Mars and creating conditions on the ground for experiment. Through repeated trials, repeated comparisons and repeated corrections, we solved the problem. In order to reduce the risks of the mission and improve the adaptability to the uncertainties of landing on Mars, Tianwen-1 adopted a ballistic lift approach, which requires the spacecraft to adjust its attitude before the entire landing process, which is called adjusting the landing angle. It was not until the Mars mission in 2011 that foreign countries began to adopt the ballistic lift approach and adjusting the landing angle was realized by dropping a mass cube, which weighed hundreds of kilograms. We adopted the new technology of trim wing and made reasonable use of the effect of Martian atmospheric resistance to adjust the angle, and the mass cost was only one tenth of that of foreign approaches," said Sun.
Sun pledged greater contribution to the development of scientific and technological innovation and the construction of a space power.