What’s the importance of lunar communications?
As space agencies and private enterprises ramp up their ambitions to build a sustainable human presence on the lunar surface, we must look to the future of communications on the Moon. Cislunar communication infrastructure is vital for sustainable lunar missions, ensuring continuous contact with astronauts, rovers, and other surface operations and transmitting information back to Earth.
The International Telecommunication Union agrees. Joanne Wilson, deputy to the director of the ITU’s Radiocommunication Bureau, has stressed the importance of technical preparations for lunar communications due to the anticipated expansion of the space industry and the growing importance of spectrum regulation beyond Earth. However, we don’t need to wait until 2027 to see this cislunar communication in action. The Federal Communications Commission recently revealed that the first licence for cislunar communications has already been granted.
What’s the engineering behind lunar communications?
There are two primary methods of lunar telecommunications: utilising the radiofrequency (RF) spectrum and using laser communications. These technologies may be used independently or in concert with each other. Using RF communications on the Moon involves transmitting and receiving RF signals using designated frequency bands, high-gain antennas, and ground stations to enable data and voice communications between lunar installations and Earth-based stations. However, the current technical capabilities make it significantly challenging to accomplish this. Consequently, incorporating laser communications that function on the Moon by transmitting high-speed data using focused laser beams between lunar and Earth orbit stations offers an ideal way to enable communications.
RF communications offer reliability over long distances and are less affected by atmospheric and space weather, like solar storms, making them ideal for space-to-Earth or Earth-to-space communications. However, they do come with a trade-off: lower data transfer rates. By contrast, laser communications provide blazingly fast data transfer and enhanced security with their narrow, focused beams and encryption potential. What’s more, the infrastructure for laser comms is far less demanding compared to RF.
However, there’s a catch: laser comms are highly directional and vulnerable to atmospheric interference. Thus, laser communication is most effective when it comes to transmission between lunar assets but might not be the go-to option for transmitting data back to Earth.
What are the regulatory issues of cislunar communications?
Navigating the regulatory landscape for cislunar communications poses a myriad of challenges as nations and private entities intensify lunar activities. A crucial focus is establishing a harmonious framework for spectrum allocation, necessitating precise coordination to avert interference amid diverse communication systems and missions.
The escalating number of missions in Earth orbit magnifies the pressing issue of interference, underscoring the imperative for a robust regulatory framework. With an expanding array of satellites, space probes, and communication systems, addressing interference becomes paramount for ensuring the seamless operation of both cislunar and Earth-based missions.
These complexities are further amplified in cislunar space, where international cooperation is vital but intricate, given participating nations’ diverse priorities and policies. Concurrently, effective orbital debris management is essential, requiring stringent regulatory measures to curb space debris proliferation and safeguard the integrity of cislunar assets. The absence of an atmosphere on the Moon compounds the debris challenge, necessitating careful consideration for lunar space.
While the Outer Space Treaty doesn’t explicitly mention communication technologies, several articles are relevant to cislunar communications in terms of international cooperation, peaceful use, avoiding harmful interference, and due regard. The Moon Agreement will not be a focal point of regulatory inspiration in the realm of cislunar communications. This is because none of the major spacefaring States have ratified it and only 18 countries are party to it (one of which, Saudi Arabia, will cease to be a party in January after giving a notice to withdraw from the treaty).
Are cislunar communications a topic at WRC-23?
Cislunar communications will feature at WRC-23 under Agenda Item 10, which calls for the drafting of future agenda items. The US has submitted a proposal for spectrum allocations and associated regulatory provisions to support lunar and cislunar communications in specific frequency bands. The proposal emphasises that administrations in all three ITU Regions have announced and are pursuing lunar missions, with human visits to the Moon set to occur as early as 2025. The proposal notes that changes to the Radio Regulations, the international treaty that governs the allocation of radio-frequency spectrum, may be necessary in some cases to accommodate the types of traffic, services, and functional capabilities that will be associated with cislunar communications.
Although the vast majority of cislunar activities are in the preliminary planning stage, this will not remain so. We are going back to the Moon, and soon. Our current architecture will help us get there, but it is cislunar communication architecture that will let us stay. Delaying action until WRC-31 might prove too late, highlighting the need to proactively address lunar communication regulations now and ensure their incorporation in the upcoming amendment to the Radio Regulations.
