Leonard David's INSIDE OUTER SPACE

NASA’s Artemis return humans to the Moon by 2024 program.
Credit: NASA

NASA is starting to define an Internet-like architecture, known as LunaNet, detailing needed space communications relay and navigation services to support the space agency’s Artemis program and its planned missions to the Moon.

LunaNet would involve position, navigation, and timing (PNT) services in support of lunar missions.

Conceptually, the LunaNet architecture embodies three types of networks: the lunar relay network, the lunar surface network, and the Earth network.

Numbers of nations are now cooperating in a vast effort to expand the sphere of human presence to the Moon and beyond. In the next decade, scores of missions will be launched to orbit or land on the Moon and begin to establish a sustained presence there.

The NASA Artemis program will send the first woman and the next man to the Moon by 2024 and develop a sustainable human presence on the Moon by 2028.
Credit: NASA

LunaNet is envisioned as supporting lunar missions – national and international, governmental and commercial – beginning in 2020.

Initial interest

“Two missions are driving NASA’s initial interest in relay services,” explains Andrew Petro of NASA Headquarters. “One is a science mission to the farside of the Moon, planned for launch as early as the second quarter of 2024. A second mission that might make use of relay services is a planned human exploration mission to near the South Pole of the Moon in 2024.”

Petro adds that, beyond these two early missions, the demand for relay services is likely to exist for additional lunar missions undertaken by NASA and by others.

Phase 1 LunaNet.
Credit: NASA

LunaNet, 2nd phase.
Credit: NASA

“Communications relay and navigation service capabilities could become part of an infrastructure enabling general expansion of robotic and human activities on the Moon,” Petro says.

Sphere of human presence

Numbers of nations are now cooperating in a vast effort to expand the sphere of human presence to the Moon and beyond. In the next decade, scores of missions will be launched to orbit or land on the Moon and begin to establish a sustained presence there.

LunaNet would provide services for various Moon-related activities, such as lunar science orbiters, lunar exploration orbiters, lunar surface mobile and stationary systems, Moon and Earth orbiters that provide relay and PNT service to lunar systems, lunar ascent and descent vehicles, and associated Earth ground stations and control centers.

Credit: NASA

LunaNet is envisioned as a network defined by a framework of frequency bands, communication and PNT protocols, and interfaces to support an open, scalable, interoperable network-of-networks for missions to use in cislunar space.

 Incremental phases

As now seen, LunaNet would be implemented in a series of incremental phases driven by major phases of human exploration and scientific discovery missions:

(1st Phase) Now-2024 – early robotic missions and crewed missions leading to the return of humans to the Moon. Initial LunaNet capability will become operational. At least one lunar relay will be launched to enable farside robotic landers and science missions and support the southern polar site.

(2nd Phase) 2024-2028 – expansion of scientific capabilities and establishment of a sustainable human presence. The number of surface sites and missions will increase. LunaNet services and capacity will expand as more service providers join.

(3rd Phase) Beyond 2028 – sustained scientific and human lunar capabilities. The cislunar region will be used to conduct Mars analog missions to prepare for eventual human missions to Mars. LunaNet will continue to expand capacity and coverage as required to meet mission needs and will act as an analog for the Mars Network, MarsNet.

Lunar south pole – future Moon base location.
Credit: NASA

Landing accuracy

In 1969, Apollo 11 overshot its intended landing site by several kilometers due to simplistic understanding of the uneven lunar gravity field. A few months later, Apollo 12 landed roughly 590 feet (180 meters) from its target, the NASA robotic Surveyor 3 lunar lander, due to rapid improvements in understanding, modeling, and analysis.

At a projected lunar south pole base station — where multiple missions will land, assemble infrastructure, and explore the surrounding region — a surface wireless network will be deployed to interconnect fixed and mobile surface users.

Concepts for a lunar base will require repeatable high landing accuracy with an error less than 330 feet (100 meters) and eventually, less than 33 feet (10 meters), according to LunaNet planners.