Moonlight is the European Space Agency (ESA) programme to create a satellite constellation orbiting the Moon, designed to provide advanced communication and navigation services.

With more than 400 lunar missions planned by space agencies and private companies over the next twenty years, Moonlight represents a fundamental step toward sustainable lunar exploration and the development of a true lunar economy.

The programme aims to support institutional and commercial missions, enabling precise and autonomous landings, surface mobility, and high-speed, low-latency data transfers between Earth and the Moon. This infrastructure will be crucial not only for humanity's return to the Moon, but also for establishing a stable and long-term presence.

Within ESA's Moonlight initiative, on 15 October 2024, Telespazio signed the Lunar Communication and Navigation Service (LCNS) contract to manage the development of a satellite constellation dedicated to providing navigation and communication services for future lunar missions.

This project involves a consortium of specialised companies, with Telespazio acting as prime contractor and responsible for the overall system. The consortium includes partners such as Hispasat, Inmarsat, Thales Alenia Space Italia, Qascom, MDA UK, KSat, Telespazio UK, Telespazio Iberica, SDA Bocconi, POLIMI, Sapienza University of Rome with the departements CRAS and SIA for the design, implementation, and operational qualification of the

The LCNS programme foresees the creation of an innovative infrastructure designed to provide essential communication and navigation services for future lunar missions. Furthermore, interoperability with LunaNet, a shared standard among the main international space agencies, will ensure cooperation among different service providers, increasing the reliability of the entire system. The infrastructure will be composed as follows:

• Lunar Space Segment: this will consist of an initial constellation of five satellites, four dedicated to navigation and one to communications. These satellites will provide high-speed, low-latency communication services as well as precise navigation signals, enabling autonomous landings and surface mobility. The satellites will be positioned to ensure wide coverage of the lunar South Pole, an area of particular interest for future missions, thanks to the presence of resources such as ice in "permanently shadowed" craters and "peaks of eternal light", ideal for solar energy generation.

• Earth Ground Segment: this will consist of at least three ground stations connected to a terrestrial infrastructure implemented on commercial cloud systems. This system will play a key role in monitoring and managing the entire infrastructure. The Earth Ground Segment (EGS) will ensure service continuity and the connection between Earth and the Moon, coordinating all constellation operations and supporting the communication and navigation network.

• Lunar User Segment: this will be composed of the terminals required to access communication and navigation services. These terminals will initially serve to validate communication and navigation services during the in-orbit qualification phase, and will subsequently provide end-to-end services to final users. Moonlight-compatible terminals are developed in Europe and can be easily adapted for system users.

LCNS services are designed to ensure high availability and daily temporal coverage. The main planned features include:

• high-capacity K-band services and wide-coverage S-band services

• real-time data relay and store-and-forward delivery

• Quality of Service (QoS) to prioritise nominal and critical operations

• real-time data transfer within seconds

• support for multiple simultaneous user sessions

A Direct-to-Earth (DTE) / Direct-with-Earth (DWE) service will complement LCNS data relay services, improving both temporal and geometric coverage.

The following navigation services are foreseen:

• Real-time services:
  • One-Way Ranging (OWR)
  • Position, Velocity and Time (PVT)
  • Time Dissemination Service (TS)
  • Two-Way Measurement (TWM – to be confirmed)
  • navigation service availability and performance prediction

• Non-real-time services enabling highly accurate post-processed PVT solutions

LCNS will be based on international LunaNet standards defined by the world's leading space exploration industries together with space agencies such as NASA, ESA and JAXA. The system will support lunar navigation and communication terminals compliant with the standard.

The Moonlight program will be implemented in phases: the first Navigation satellite will enter service in 2029, while the other satellites will follow in 2031, ensuring full operational capability of the services.

LCNS will not only meet the needs of human and robotic space exploration, but will also create commercial opportunities for European industry within the emerging lunar economy. The satellite network will allow missions to communicate simply and efficiently, even from lunar regions not visible from Earth, reducing the need for Direct-to-Earth communications and improving overall operational efficiency. This system will be essential for enabling new applications, technological innovations, and sustainable exploration of the Moon, with a significant impact on containing mission costs.

Furthermore, the navigation signals provided by the LCNS satellites will enable extremely precise positioning, reducing the complexity of the onboard navigation systems of landers, rovers, and orbiters. This will help save costs and facilitate navigation for future exploration missions, both human and robotic.