(ORDO NEWS) — China plans to create a constellation around the moon to provide communications and navigation for future operations on the lunar surface.
China will take the lead in demonstrating a small lunar communications and navigation relay system, Wu Yanhua, deputy director of the China National Space Administration (CNSA), said on April 24.
The first launch of the small constellation could take place in 2023 or 2024, according to Wu, who added that countries around the world are invited to co-create the system.
No further details were provided, but China’s lunar roadmap and mission concepts give an idea of the plans.
The relay communications and navigation services will be used primarily to support the Chang’e-7 and sample return mission, which includes an orbiter, a lander, a rover and a small hopping spacecraft to examine shadowed craters for water ice.
Wu said at a National Space Day ceremony that Chang’e-6 could be launched in 2024 or 2025. Earlier it was reported that the launch of Chang’e-7 is scheduled for about the same time, and possibly even earlier than Chang’e-6.
Chang’e-6 and Chang’e-7 are expected to land near the south pole of the moon. Although China has a relay satellite placed in a halo orbit around the Earth-Moon Lagrange point 2 to communicate with the Chang’e-4 lander and the Yutu-2 rover on the far side of the Moon, to improve communication and transmit large volumes data between Earth and the south pole of the moon would require a different orbit.
Designed to use resources in situ and test 3D printing technology, Chang’e-8 will be a stepping stone towards the International Lunar Research Station (ILRS) in cooperation with Russia.
The ILRS project provides for the construction of a permanent robotic base on the Moon in 2030-2035. Once completed, the base will be capable of long-term human habitation.
NASA, the European Space Agency and private firms are also planning a lunar communications and navigation infrastructure to support the Artemis lunar exploration program. The Artemis and ILRS projects are seen by some as the initial stages in the development of an emerging lunar economy.
China’s lunar communication and navigation constellation is likely to be built up gradually, providing more and more capabilities as the lunar plans are realized.
One concept for a relay satellite to support Chang’e-7 is to use an inclined, highly elliptical orbit with a 300 km permoon, an 8,600 km alunar, and an inclination of 54.8 degrees. This will allow communication between the Earth and the south lunar pole for more than 8 hours during a 12-hour orbital period.
Adding more satellites in similar orbits will provide continued communications and navigation coverage.
However, other possibilities are also being considered. Christine Burke, a researcher at the China Aerospace Research Institute (CASI), said the extended activity of Chang’e-5 could be used to test new orbits for the constellation.
“Articles by Chinese scientists show that China is considering several different combinations of orbital modes for communications and navigation architecture. Some of these include DRO satellites,” says Burke.
The first relay satellite can be launched on a special carrier rocket or as part of the Chang’e-7 spacecraft stack. The relay satellite is likely to be the first step to facilitate new, more sophisticated activities at the lunar south pole as part of China’s long-term plans for lunar exploration.
Contact us: [email protected]