The Future on the Moon: How LunaNet and Moon Standard Time will Shape the Lunar Economy

The Moon has long fascinated humankind, inspiring countless myths, stories, and scientific inquiries. Our understanding of the Moon has shifted gears in recent years owing to several outer space missions that explored geology, surface, and, mineral resources. The idea of building a lunar economy has existed for some time now. To make it a reality, scientists will have to set up a communication and navigation infrastructure with a standardized way to determine time.

NASA is currently in the early stages of developing LunaNet, a vital initiative to create an internet network for the Moon. This project goes beyond enabling astronauts to take pictures; it is a crucial component of the Artemis program. The agency intends to build various infrastructures on and around the Moon, such as a human habitat, a new space station, and a lunar web service that can maintain connectivity between all elements.

“LunaNet is a framework of mutually agreed-upon standards, protocols, and interface requirements allowing future lunar missions to work together, conceptually similar to what we did on Earth for joint use of GPS and Galileo,” explains Javier Ventura-Traveset, ESA's Navigation Manager.

LunaNet: Enhancing Connectivity and Empowering Missions at the Moon

“As NASA establishes a sustained lunar presence on the Moon, creating a robust infrastructure becomes increasingly important. The LunaNet communications and navigation architecture is extensible and flexible,” states D.J. Israel, Exploration and Space Communications Projects Division Architect in a conference paper titled “LunaNet: a Flexible and Extensible Lunar Exploration Communications and Navigation Infrastructure.”

He further explains how LunaNet will provide three types of services: networking, position, timing and navigation, and science utilization. Users, both human and robotic, will experience network functionality similar to that experienced on Earth.

The ESA(European Space Agency) opened an application portal last week,  inviting private companies to help with its “Moonlight” program, aimed at launching  three or four satellites to be “carried into lunar orbit by a space tug and deployed one by one, to form a constellation of lunar satellites.” The satellite constellation's orbits will be strategically optimized to encompass the lunar south pole, which has been designated as the primary landing site for  NASA’s future Artemis missions.

What is ESA’s Moonlight initiative?

“Many of the proposed lunar missions will require reliable navigation and telecommunication capabilities. Building these capabilities independently would be inefficient and costly due to complex, recurrent developments,” ESA’s announcement blog post titled “Lunar Economy Applications” read.

Not only ESA, but NASA has also adopted public-private models for providing space services, such as delivering cargo and transporting crew to the International Space Station. These partnerships have also been established for future endeavors, including the delivery of scientific experiments and astronauts to the lunar surface.

NASA has invested $1.2 billion in SpaceX to develop a human landing variant of Starship to land American astronauts on the Moon under Artemis III,” marking humanity’s first return to the lunar surface in more than 50 years.”

Of the total investment in space over the last decade, which amounted to $272 billion, 99% was directed toward the development of satellites and their launch vehicles for Earth's orbit. The emerging markets of space habitats, satellite servicing, and the fledgling lunar market accounted for $3.3 billion of this investment.

The US-based space agency anticipates that the lunar network will expand along with the increase in activity on and around the Moon. It projects that with the establishment of the Lunar Gateway, its newly planned lunar space station, the Moon will require approximately 210 megabits per second and 4.6 terabytes per day, as stated in a presentation from the agency in the previous year. As NASA prepares for a human mission to Mars around 2035, it foresees the Moon requiring as much as 950 megabits per second and 12 terabytes per day.

"In 2021 there were 13 landers, orbiters, and rovers on and around the Moon," Kelly Larson, CEO of Aquarian Space, said in the statement. "By 2030, we will have around 200, creating a multibillion-dollar lunar economy.”

NASA is devising a plan to enhance its services by launching lunar satellites that will interconnect with each other and eventually link back to the communication infrastructure on Earth. The relay spacecraft will be especially beneficial for the challenging-to-reach parts of the Moon, such as the far side and the lunar south pole, which the agency aims to explore with the aid of astronauts in the future. Furthermore, the agency intends to establish a range of ground stations that will function like cell towers on the Moon's surface. The idea is to create a lunar communication system that operates similarly to an internet network rather than a phone line.

Private companies, including Aquarian Space and Nokia, are contributing to the development of lunar internet infrastructure. Aquarian Space plans to launch its initial lunar communication satellites by Q2 2025, while Nokia is collaborating with NASA on a 4G cellular network for the Moon. Nokia has won a contract of over $14 million from NASA and is scheduled to deliver its first base station and radio equipment via a SpaceX rocket next year.

Accurate navigation depends majorly on precise timekeeping as it is crucial in determining the exact location of a satnav receiver. The satnav receiver measures the time it takes for multiple satellite signals to reach it and converts this time measurement into an estimate of distance.

Currently, every new expedition to the Moon is conducted on Earth's timeline, with the assistance of deep space antennas to ensure that the spacecraft's clocks are aligned with terrestrial time and to enable communication between the spacecraft and Earth. However, this approach will not be viable in the future lunar environment.

There are over 250 lunar missions planned in the coming decade. These missions will not only occur simultaneously on or around the Moon, but they will also frequently interact with each other. This interaction may involve relaying communications, conducting joint observations, or carrying out rendezvous operations.

Considering this, space agencies have initiated discussions on how to measure time on the Moon. These discussions began with a meeting at ESA's ESTEC technology center in the Netherlands in November of last year.

"During this meeting at ESTEC, we agreed on the importance and urgency of defining a common lunar reference time, which is internationally accepted and towards which all lunar systems and users may refer to. A joint international effort is now being launched towards achieving this,” said ESA navigation system engineer Pietro Giordano.

“Timekeeping and time distribution are essential for navigation performance and for maintaining synchronization across multiple assets. Time knowledge significantly impacts observation accuracy. Inaccuracies and differences among sources used in measurement time-tagging impart offsets relative to the true orbit location,”  states the conference paper.

Observations commonly used in radio and optometric technologies include one-way and two-way range and Doppler measurements. These observations heavily rely on precise time-stamping, which must be referenced to a standardized time scale such as International Atomic Time (TAI).

Establishing a universal lunar time presents a unique challenge as clocks on Earth and the Moon operate at different speeds due to the varying gravitational fields. As such, the form that an official lunar time would take is not clear. One possibility is that lunar time could be based on a clock system that is designed to synchronize with Coordinated Universal Time (UTC). Alternatively, lunar time could be entirely independent of Earth time, resulting in the creation of a unique time system specifically designed for the Moon.

According to Jeff Gramling's estimation, a lunar clock would gain approximately 56 microseconds or millionths over 24 hours. The exact rate will be a function of their position on the moon, ticking differently on the lunar surface and orbit.

Other than technical standpoints, geopolitics will play a major role in building the lunar economy. The entity that shapes the internet infrastructure on the Moon will wield significant influence, as it will have the authority to establish guidelines for how network providers collaborate and allocate lunar web addresses.

Despite the U.S.'s efforts to bring other nations and space agencies into alignment with its Artemis Accords, a set of international principles aimed at guiding lunar and outer space exploration and development, there is no assurance that all parties will agree to its terms. Notably, Russia and China are collaborating on their own lunar initiatives.

For effective collaboration, the international community must agree upon a shared "selenocentric reference frame," similar to the International Terrestrial Reference Frame used on Earth, which allows for accurate measurement of precise distances between points across the Moon. Such customized reference frames are crucial components of modern GNSS (Global Navigation Satellite Systems).

Once the scientists are able to move past the challenges, the construction of Gateway stations will be open to astronauts’ stay and will be resupplied with periodic Artemis launches. Numerous uncrewed missions will also be in place – each Artemis mission alone will release numerous lunar CubeSats – and ESA will be putting down its  Argonaut European Large Logistics Lander.