The Chang 'e-5 lunar probe successfully completed its 48-hour mission at 3:10 PM On December 3, Beijing time, and successfully lifted off from the lunar surface for its first "lift-off" of an extraterrestrial body. Not only that, But China has successfully displayed a "fabric version" of its five-starred red flag on the moon for the first time. Before ignition and takeoff, the lander's lifter assembly unfurls the lunar flag and unlocks and separates the lifter from the lander. This is China's first independent display of the national flag on the lunar surface. Unlike the national flags on the Chang 'e-3, Chang 'e-4 and Yutu lunar rover, which were painted in different ways, the Chang 'e-5 national flag is a real one.

The lunar national flag display system was jointly developed by China Aerospace Sanjiang Group and Wuhan Textile University. It is composed of the lunar national flag, a pressure release device and a spreading mechanism, and is about half a meter long. The system was launched with the probe in a folded state, and was unlocked after landing on the moon.

According to the report, the national flag on the lunar surface was mounted on the outside of the lander without any temperature control protection. When the fairing falls off, the flag will face extreme environmental conditions such as high vacuum, high and low temperature circulation and strong ultraviolet radiation in space. In order to ensure the perfect presentation of the national flag on the lunar surface, the research team went through a series of scientific and technological breakthroughs to develop a high-performance textile flag with Chinese characteristics that can withstand extreme environmental conditions.

It is understood that the flag is mainly made of domestic high-performance arylon fiber and adopts the "efficient short-flow embedded composite spinning technology", which has won the first prize of national science and technology progress. It overcomes the technical problem of producing high-quality yarn with high modulus difference fiber and produces high-quality lunar surface display flag fabric. The structure regulation and color construction of arylon fiber are realized by using small molecule regulation technology, and on this basis, excellent fastness to sunlight under extreme ultraviolet condition is realized. At the same time, nanometer silk powders were prepared by using the "superfine pulverization of high quality natural polymer materials and reuse technology with high added value", which won the second prize of national science and Technology invention. The synergism with pigment particles was used to solve the problems of pigment heat sublimation and heat transfer fastness under extreme conditions. Through the above technical breakthroughs, the purpose of constructing the color fastness of the national flag in space environment under the conditions of extreme high vacuum, high and low temperature circulation and strong ultraviolet irradiation is realized.