Earth-Moon L2 relay link.
Credit: CNSA


The China National Space Administration (CNSA) has announced the name of the relay satellite to be used in the country’s Chang’e-4 far side Moon lander project.

Enter drum roll: “Queqiao” – bridge of magpies.

As explained by China’s Xinhua news agency: In a Chinese folktale, magpies form a bridge with their wings on the seventh night of the seventh month of the lunar calendar to enable Zhi Nu, the seventh daughter of the Goddess of Heaven, to cross and meet her beloved husband, separated from her by the Milky Way.

Together with the relay satellite, two microsatellites, developed by the Harbin Institute of Technology, will also be sent into orbit to conduct scientific research. The names of those two satellites were also announced: “Longjiang-1” and “Longjiang-2.”

Chang’e-4 Moon lander and rover.

Late May launch

Slated for launch in late May by a Long March-4 rocket, the relay satellite is to be placed into a halo orbit of the Earth-Moon Lagrange Point L2. The relay satellite and rocket are both at the launch center in Xichang, southwest China’s Sichuan Province.

Six months later, the Chang’e-4 far side lander and rover will be sent to the Moon. Chang’e-4 also will tote payloads for Germany, the Netherlands, Saudi Arabia and Sweden.

Aitken crater, located at 17 S, 173 E, anchors the northern rim of the South Pole-Aitken basin.
Credit: NASA/GSFC/Arizona State University


Gravitational equilibrium

As reported by Xinhua, Bao Weimin, director of the Science and Technology Commission of the China Aerospace Science and Technology Corporation said: “We designed an orbit at the Earth-Moon Lagrange Point L2 about 450,000 kilometers from the Earth, where a gravitational equilibrium can be maintained, and the relay satellite will be able to ‘see’ both the Earth and the far side of the Moon.”

Bao added that the whole mission “is very complex and challenging. We feel great pressure, but we are confident.”

The relay and microsatellite names were announced on China’s “Space Day.” April 24 marks the day when China’s first satellite was sent into space in 1970, and has been celebrated as the country’s Space Day since 2016.

Credit: New China/Screengrab


Sample return next year

In a related Xinhua news agency story, CNSA’s Pei Zhaoyu, deputy director of the Lunar Exploration and Space Program Center said the launch of Chang’e-5 lunar probe is planned for next year.

That mission is designed to bring lunar samples back to the Earth. Chang’e-5 was delayed from last year due to a Long March-5 booster failure and subsequent investigation of the mishap. That heavy-lifter rocket is needed to hurl the return sample craft moonward.

Credit: New China/Screengrab

Complex undertaking

Pei said that the Chang’e-5 lunar probe will be very complex, containing four parts: an orbiter, a returner, an ascender and a lander.

The Moon lander will grab and stash lunar samples in the ascender. Rocketing off the lunar surface, the ascender is to rendezvous and dock with the orbiter, then transfers the collection into the returner, Pei said.

Credit: New China/Screengrab

The orbiter and returner would head back to the Earth, Pei said, separating from each other when they are several thousands of kilometers from the Earth. Finally, the returner will make its way back to the Earth.

In the Xhinua reporting, Tian Yulong, secretary general of CNSA, said after fulfilling the three steps of China’s lunar probe program — orbiting, landing and returning – the country will conduct further lunar exploration, including landing and probing the polar regions of the Moon.

For a behind-the-scenes look at China’s Chang’e-5 mission preparations, go to this CCTV-Plus video:


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