The author is an astronomer, science communicator and professor of science education at UQAM.
the capsule launch spatial Orion to the moon, last November 16, as part of the Artemis 1 mission, marks NASA’s return to the race for the Moon, in which the Chinese space agency is also involved. The ultimate objective of this vast undertaking is no longer, as in the days of the Apollo missions, to make a short stay on our satellite. The declared ambition is indeed to install a permanent base on the Moon and to have astronauts live there for long periods of time, a form of dress rehearsal for a possible trip to the planet Mars. Which raises an important question: is it possible to live on the Moon?
Remember that in the absence of an atmosphere, the new inhabitants of the Moon will constantly have to live in a tight bubble, whether it is their space suit or the base itself. They will have to protect themselves against lunar temperature variations, which fluctuate between 130 degrees Celsius during the day and -170 degrees Celsius at night. They will also need a constant supply of oxygen, water, and food, not to mention the energy needed to run various systems. Fortunately, several solutions are available to them.
For example, we are almost convinced that there is water, in the form of ice, under the lunar surface, in particular near the poles. If it can be accessed, this water could quench astronauts’ thirst and, by separating oxygen from hydrogen by electrolysis, provide them with all the oxygen they need. With water, you can also grow plants hydroponically, which also partly solves the question of food. And of course, Earth is never far away if supplies are needed…
The electrolysis of water requires electrical energy, which will not be lacking for half a lunar day, thanks to the solar panels that will not fail to be installed near the base. But what to do during the long lunar night, which lasts 14 days? This is where the hydrogen produced during the electrolysis of water becomes useful, if it can be stored and used in hydrogen fuel cells. Otherwise, a mini nuclear power plant would be another solution, but it would first have to be installed on board a rocket and launched from the Earth, with all the risks that entails.
During their short trips to the Moon, the astronauts of the Apollo missions had relatively little exposure to the deadly radiation from which we, here on Earth, are shielded by the Earth’s atmosphere and magnetic field. Since the Moon has neither, its surface is constantly bombarded by UV, X and gamma rays, not to mention cosmic rays, charged particles moving at very high speeds. All of these forms of radiation have the power to damage living tissue and cause cancer, not to mention the damage they can inflict on exposed surfaces and equipment on the Moon.
Protons, charged particles found at the heart of atoms and abundant in cosmic rays, are of most concern because they can damage cells, break strands of DNA and, at levels of high exposures, killing cells and causing irreparable damage to organs. A good way to protect the astronauts will be to bury the base under a thick layer of lunar soil, failing to transport heavy metal plates to the Moon to act as anti-radiation shields. This envelope of lunar soil will also protect astronauts from micrometeorites that constantly bombard the lunar surface.
Finally, a word on the lunar soil itself, the regolith, which covers the surface several centimeters thick. It is a fine powder of silicon dioxide, similar to flour, but with high abrasive power and strong static attraction. Astronauts on the Apollo missions have reported seeing it stuck all over their gear and suits, and said they were unable to get rid of it once it infiltrated their spacecraft. Although the toxicity of moon dust is not yet clearly established, astronauts on the Apollo missions have often complained of eye, nose and lung irritation.
Anyone who’s ever spent a sunny day on a beach knows that fine sand has a nasty habit of getting everywhere. We dare not imagine what the interior of a lunar base will look like after a few months of continuous use!