The National Space Administration reported on April 12 that the Queqiao-2 relay satellite, which was launched on March 20 this year, has completed the on-orbit communication test and the mission was a complete success. In 2018, the first generation of Queqiao was launched, and now Queqiao 2 is “new”, let’s find out more!
Why launch the Queqiao series of relay satellites?
Because the earth cannot communicate directly with the spacecraft on the far side of the moon, before Chang'e-4 went to the far side of the moon, a relay satellite had to be sent to a designated location to build a "bridge" for earth-moon communication.
This "bridge" is the Queqiao relay star. It opens an antenna like a "big umbrella" to help the probe "communicate" with the earth and provide communication services for Chang'e-4 working on the back of the moon.
With the Queqiao number, why do we still need to build a new "Magpie Bridge"?
Queqiao 2 is an upgraded version of Queqiao. Queqiao has a design life of 5 years and is currently serving beyond its scheduled service. Queqiao 2 has a design life of 8 years. It will take over the important task in the future and continue to escort the "Chang'es".
The fourth phase of the lunar exploration project mainly targets the lunar south pole and the far side of the moon. Queqiao orbits the Earth-Moon Lagrange L2 point, mainly focusing on the far side of the moon. The lunar south pole is too far away for Queqiao, so Queqiao was dispatched. 2, its work focuses on covering the lunar south pole region.
After Queqiao 2 sets off, it will carry out its work in two stages. First, it will operate for a period of time in a large elliptical frozen orbit around the moon with a period of 24 hours. Then, Queqiao-2 will change its orbit into a large elliptical frozen orbit around the moon with a period of 12 hours.
In these two orbits, an oscillating balance point of the earth's gravity has been found, allowing the spacecraft to operate stably for a long time without consuming too much propellant, so it is called a "frozen orbit".
When performing the task of "communicating feelings and expressing feelings", both generations of Queqiao adopted the "regenerative forwarding" mode. Not only can he "pass notes" by "going in with his left hand and out with his right hand", but he can also "write letters on his behalf". Queqiao-2’s “regenerative forwarding” mode can also support the coordination of multiple detection missions at the same time.
Teach you a trick: identify two generations of "Queqiao" at a glance
Behind the "big umbrella" shaped antenna of Queqiao are three "braids", which are low-frequency radio antennas used for scientific observations. The corresponding position of Queqiao No. 2 has changed from three braids to one, and is paired with a "small pot".
What is this little pot for? Since Queqiao-2 works in a lunar orbit, in order to always maintain signals pointing to the earth and the moon at the same time, in addition to the "big umbrella" antenna pointing to the moon, it also needs a "small pot" antenna to point to the earth. Relying on that "braid", it continuously adjusts its direction during the orbit around the moon and maintains real-time communication with the earth.
Compared with Queqiao-2, Queqiao-2 is larger, more difficult to develop, has more functions, has a longer mission span, and also bears more important responsibilities. It will provide relay communication services for Chang'e-6, which is about to "dig soil" on the far side of the moon, and Chang'e-7 and 8, which are building basic models of the international lunar scientific research station. At the same time, scientific exploration missions such as Earth magnetotail observation will also be carried out simultaneously.
Let us look forward to the new Queqiao transmission, which will reveal more mysteries of the far side of the moon for us.
Planner: Qian Tong, Chang Ailing, Liu Jing
Producer: Qi Huijie, Zhou Ningling, Weijia
Producer: Yang Yuhua, Hu Guoxiang
Final review: Cao Jianli, Jiang Chen, Antao
Reporter: Wu Huijun, Song Chen, Dai Wei
Hand-painted design: Shi Meng
Editor: Wang Wenyuan, Wang Yuxuan
Copywriter: Qu Jiong, Chen Biqi
Production: Deep Space Singularity™
Guidance unit: National Space Administration Lunar Exploration and Space Engineering Center
Xinhua News Agency New Media Center
Xinhua News Agency Anhui Branch
Deep Space Exploration Laboratory
Co-produced
(Source: )