China has a planned manned lunar base, the International Lunar Research Station (ILRS), that will need to have regular communications with the Earth. It will rely on using a relay system, Queqiao, in lunar orbit to allow for higher availability connections, however, even with this relay system, China will be limited by orbital mechanics in how often they could connect if they use ground stations in mainland China. China could use global deep space networks, like the one in Neuquén, Argentina, however they are concerned about being dependent on other nation states with increasing global political tensions. This is a reasonable concern for China as they lost access to their ground station in Kiribati in 2003 due to Kiribati recognizing Taiwan. Furthermore, this mission is planned for the 2030’s, making the political climate even less predictable– China does not want to end up in a situation where its astronauts and bases are regularly dependent on other countries for a large portion of communication.

The second relay would be the use of geosynchronous satellites. The GEO constellation would be Tianlian, and it was used in China’s dark/far side of the moon missions. The Tianlian constellation is 3 satellites each 120 degrees from one another, thus offering a large range of global and lunar connections. This constellation would currently offer about 75% coverage to the Queqiao relay without any additional antennas or satellites, vastly improving the current limitations. They would need to add another satellite to approach 100% connectivity, but that seems like a small cost to pay if they are concerned about relying on other nation states.

From a cyber perspective, there are reasonable concerns with using deep space networks in other countries. Many of them are older with known vulnerabilities and the data generally needs to go through other data centers/servers managed by other nations and it is unlikely China wants this data to be public. There is also the issue of physical access, which China cannot control from the other side of the Earth. Using the dual relay approach would mean that China is not dependent on any other nation for their communications and could more easily secure their data. To steal or compromise this data, the attacker would need to either compromise the Queqiao relay or the Tianlian constellation, which is much more complicated than attacking an existing deep space ground station as they are in lunar and GEO orbit and the ground stations are directly managed by China. Overall, China’s approach makes sense to secure communications for their lunar base. They do likely need to find a way to bridge the last 25% of connectivity, but the peace of mind being offered to their astronauts is hard to quantify. In the future I would expect the US to have similar plans, although right now it is focused more on a similar system for Mars which Blue Origin, Lockheed and SpaceX have won contacts for this year [2].

Sources:
Primary – https://spacenews.com/china-could-develop-dual-relay-satellite-system-for-earth-moon-communications-to-reduce-geopolitical-risks/
[2] – https://spacenews.com/nasa-awards-studies-for-commercial-mars-missions/