Artemis: The Lunar South Pole Base

Humans have not visited the moon since 1972, but that’s about to change. Thanks to NASA’s Artemis missions, we have already taken the first small step towards our own lunar home for astronauts. NASA has established the second generation of its lunar missions- “Artemis”, fittingly named after the ancient Greek Goddess of the Moon, and Apollo’s twin. The ultimate aim of the Artemis missions is to solidify a stepping stone to Mars. Technologies will be developed, tested, and perfected, before confidence is built to travel on to Mars.

NASA has to consider the natural conditions of the Moon, since doing so will allow astronauts to limit their reliance on resources from Earth, and increase their length of stay and therefore potential for research. The amount achieved would be extremely limited if a lunar mission relied solely on resources from Earth, due to the limitation of rocket payloads [1]. This is known as In-Situ Resource Utilisation, and in addition to extended lunar stays, its success on the Moon is essential if we hope to one day establish a base on Mars [2]. As a priority, astronauts need to have access to energy and water. Luckily, the conditions at the lunar south pole may be ideal for this. Unlike Earth, where we experience seasons due to its 23.5° tilt, the Moon’s tilt is tiny, at only 1.5°. This means some areas at the lunar poles are almost always exposed to sunlight, providing a reliable source of solar energy generation for a potential Artemis Base Camp. And since the Sun is always near the horizon at the poles, there are even areas in deep craters that never see the light. These areas of “eternal darkness” can reach temperatures of -235°, possibly allowing astronauts access to water ice.

Aside from access to resources, Artemis has to consider the dangers that come from living in space. Away from the safety of Earth’s protective atmosphere and magnetosphere, astronauts would be exposed to harsh solar winds and cosmic rays. To combat this, NASA hopes to make use of the terrain surrounding the base, highlighting another advantage of the hilly south pole [3]. The exact location for the Artemis Base is currently undecided. We just know it will most likely be near a crater rim by the south pole, and on the Earth-facing side to allow for communication to and from Earth.

Not only is the south pole ideal from a practical standpoint, it is also an area of exciting scientific interest. Scientists will have access to the South Pole–Aitken basin, not only the oldest and largest confirmed impact crater on the Moon, but the second largest confirmed impact crater in the entire Solar System. With a depth of up to 8.2 km, and diameter of 2500 km [4], it is thought this huge crater will contain exposed areas of lower crust and mantle, providing an insight into the Moon’s history and formation [5,6]. Additionally, thanks to areas of “eternal darkness” the ice water found deep within craters at the south pole may hold trapped volatiles up to 3.94 billion years old, which, although not as ancient as previously expected, can still provide an insight into the evolution of the Moon [7].

The scientific potential of the Artemis Base Camp extends far beyond location specific investigations to our most fundamental understanding of physics, from Quantum Physics to General Relativity [2]. Not to mention the astronauts themselves, as well as “model organisms” which will be the focus of physiological studies into the effects of extreme space environments [8].

Artemis Timeline Overview:

Artemis 1 launched on 16th November 2022. It successfully tested the use of two key elements of the Artemis mission- Orion and the Space Launch System (SLS)- with an orbit around the moon. Orion, named after the Goddess Artemis' hunting partner, is the spacecraft that will carry the Artemis crew into lunar orbit. It is carried by the SLS, NASA’s super heavy-lift rocket, one of the most powerful rockets in the world.

Artemis 2 plans to launch late 2024 and will be the first crewed Artemis mission, with a lunar flyby bringing four astronauts further than humans have ever travelled beyond Earth. Artemis 3 plans to launch the following year. It will be the historic moment that will see humans step foot on the surface of the moon for the first time since we left in 1972. The mission will be the first use of another key element of the Artemis missions- the Human Landing System (HLS). Astronauts will use a lunar version of SpaceX’s Starship rocket as the HLS for Artemis 3 and 4. (Starship is currently in its test stage, with its second test launch carried out very recently on the 18th November 2023.) Two astronauts will stay on the lunar surface for about a week, beating the current record of 75 hours on the Moon by Apollo 17.

Artemis 4 plans to launch in 2028. The mission will include the first use of Gateway, another key element to the Artemis missions. Gateway will be a multifunctional lunar space station, designed to transfer astronauts between Orion and HLS, as well as hosting astronauts to live and research in lunar orbit. Gateway will be constructed over Artemis 4-6 , with each mission completing an additional module [9].

NASA plans to have Artemis missions extending for years beyond this, with over 10 proposed and more expected. Eventually we will have a working base on the Moon with astronauts able to stay for months at a time. Having already started a year ago, Artemis will continue to expand our horizons. We can look forward to uncovering long held secrets of the Moon, and soon, setting our sights confidently on Mars.

Written by Imo Bell

References:

1. How could we live on the Moon? - Institute of Physics. Available at: https://www.iop.org/explore-physics/moon/how-could-we-live-on-the-moon

2. Understanding Physical Sciences on the Moon - NASA. Available at: https://science.nasa.gov/lunar-science/focus-areas/understanding-physical-sciences-on-themoon

3. NASA’s Artemis Base Camp on the moon will need light, water, elevation - NASA. Available at: https://www.nasa.gov/humans-in-space/nasas-artemis-base-camp-on-the-moon-will-need-ligh t-water-elevation

4. Zuber, M.T. et al. (1994) ‘The shape and internal structure of the Moon from the Clementine Mission’, Science, 266(5192), pp. 1839–1843. doi:10.1126/science.266.5192.1839.

5. Flahaut, J. et al. (2020) ‘Regions of interest (ROI) for future exploration missions to the Lunar South Pole’, Planetary and Space Science, 180, p. 104750. doi:10.1016/j.pss.2019.104750.

6. Moriarty, D.P. et al. (2021) ‘The search for lunar mantle rocks exposed on the surface of the Moon’, Nature Communications, 12(1). doi:10.1038/s41467-021-24626-3.

7. Estimates of water ice on the Moon get a ‘dramatic’ downgrade - Physics World. Available at: https://physicsworld.com/a/estimates-of-water-ice-on-the-moon-get-a-dramatic-downgrade

8. Biological Systems in the lunar environment - NASA. Available at: https://science.nasa.gov/lunar-science/focus-areas/biological-systems-in-the-lunar-environme

9. Https://www.nasa.gov/wp-content/uploads/static/artemis/NASA: Artemis - NASA. Available at: https://www.nasa.gov/specials/artemis