China is working on the latest lunar relay satellite to help future lunar exploration missions reach the moon’s south pole. Around 2024, China plans to launch the Chang’e-7 spaceship to the lunar south pole. Surveying the region and looking for indications of water ice with a lander, rover, orbiter, and a tiny hopping probe to study shadowed craters are among the goals.
The mission is among the first in a proposed collaborative International Lunar Research Station (ILRS) with Russia and maybe additional partners for an initial phase. According to an article published in the Space: Science & Technology, a dedicated relay satellite is presently being constructed to establish a link between numerous surface spaceships at the lunar south pole—the position of which causes line-of-sight challenges for communications—and Earth.
A lunar relay satellite is currently stationed in orbit above the second Earth-moon Lagrange point, approximately 65,000 kilometers beyond the moon, by China. The Queqiao satellite, launched in May 2018, serves as a communications relay, allowing the Chang’e-4 lander and rover operation to function on the moon’s far side.
Queqiao’s huge 4.2-meter parabolic antenna and hydrazine propulsion will be carried over to the prospective lunar relay satellite that China will make. It will, however, possess a wet mass of about 600 kilograms, making it huger than Queqiao, which has a wet mass of 450 kilos. The satellite is expected to have an 8-year mission life. The latest satellite will be in a highly elliptical inclined frozen orbit. It will possess a perilune of about 300 kilometers as well as an apolune of about 8,600 kilometers, with a 54.8-degree inclination. This will enable communication lines to last for more than 8 hours during the orbit’s roughly 12-hour period.
According to a document written by Zhang Lihua of DFH Satellite Company limited, Ltd., a satellite-developing affiliate of the CAST (China Academy of Space Technology), the relay satellite might launch on a unique launcher or even as part of the Chang’e-7 stack. If 100% coverage is desired, a second relay spacecraft could be built.
Later in the 2020s, China plans to launch Chang’e-8, a technological demonstration project to the lunar south pole, including in-situ resource use and 3D-printing technology experiments. Around 2024, the Chang’e-6 lunar sample return is expected to aim at the South Pole-Aitken Basin, a massive impact basin that stretches from the Aitken crater at about 18 degrees south to the lunar South Pole.
The study suggests a long-term Chinese lunar communication infrastructure to deal with the predicted rise in spacecraft and the requirements of human lunar exploration. For all this to be achieved, the establishment of the lunar information network comprising orbiting and surface elements, as well as navigational data, is proposed. It is also suggested that new optical communication technologies be used for extraordinarily high data speeds.