NEW DELHI, India — China is preparing to place a new communications satellite in lunar orbit to facilitate ambitious upcoming moon landing missions.
Queqiao-2 is set to launch on a Long March 8 rocket from the coastal Wenchang spaceport in early 2024, according to Zhang Lihua of DFH Satellite under the China Aerospace Science and Technology Corp. (CASC), the satellite’s developer.
The 1,200-kilogram satellite will feature a 4.2-meter-diameter parabolic antenna and a mission lifetime of more than eight years, Zhang said during a presentation at the 74th International Astronautical Congress (IAC) in Baku, Oct. 3.
Li Guoping of the China National Space Administration (CNSA) presented a slide detailing China’s exploration timeline earlier at IAC indicating Queqiao-2 is set to launch in March.
Its initial task will be communications support for Chang’e-6; a first-ever attempt at collecting samples from the far side of the moon. That mission is scheduled to launch in Q2 2024 and will target the mid-latitude Apollo crater within the South Pole-Aitken basin.
The moon is tidally locked to the Earth, meaning that one hemisphere of the planetary body always faces our planet. Queqiao-2’s 24-hour-period, elliptical frozen orbit will take it out beyond the moon, from which it will have line of sight with both ground stations on Earth and Chang’e-6 in Apollo crater. Chang’e-6 lunar surface operations will likely be wrapped up in around 48 hours.
Queqiao-2 will then support the 2026 Chang’e-7 and 2028 Chang’e-8 missions to the lunar south pole. The lunar satellite will switch to a 12-hour period orbit for these missions. It will meanwhile assist the ongoing Chang’e-4 lunar far side lander and rover after the short-term Chang’e-6 mission. The elliptical frozen orbit is very stable, according to Zhang, requiring little fuel for maintenaince.
Queqiao-2, or “Magpie Bridge-2”, is a more capable follow-up to Queqiao, launched in 2018 to facilitate the Chang’e-4 mission. That first relay satellite remains operational in a halo orbit around the Earth-moon Lagrange point L2 roughly 70,000 kilometers beyond the moon.
It will use X and UHF bands to communicate with spacecraft, and S and Ka-bands for communications with Earth. It features multiple data rates and reconfigurable software.
The new satellite will launch with a pair of experimental CubeSats, named Tiandu-1 and Tiandu-2, to test lunar communications and navigation payloads.
The CubeSats are being developed by China’s new Deep Space Exploration Laboratory (DSEL) under CNSA, which is playing a growing role in the country’s lunar exploration and related diplomatic efforts.
Queqiao-2 also carries science payloads. These are an extreme ultraviolet camera, an array neutral atom imager and an Earth-moon length baseline very long baseline interferometry (VLBI) experiment.
The spacecraft could also aid other countries’ lunar efforts. “Apart from providing relay support for future Chinese lunar missions, it is possible to provide relay communication services for other lunar landing exploration missions at the lunar south pole or lunar far side in the future,” Zhang said.The Queqiao-2 satellite is also potentially the next step in a constellation of the same name.
The wider Queqiao constellation would provide communications, navigation and remote sensing support for China’s International Lunar Research Station (ILRS) project. Notably, an expanded future version of the network would include relay satellites at Venus and Mars to assist deep space exploration.