Interview with James Carpenter, Lead for Moon and Mars Science and Moon Utilisation Manager for the European Space Agency’s Directorate of Human and Robotic Exploration
Why are we returning to the Moon?
Well, there’s a lot of different answers to that. From a scientific perspective, we are witnessing a renewed interest in the Moon. Despite the period of low activity that followed the Apollo missions, the samples collected during those missions have provided an extremely rich body of information, still under examination today, which has left us with more questions than answers. At the same time, the orbital missions around the Moon in recent years have given us a global view that we didn’t have before. And the combination of this evidence (the global view and the returned samples) has shown us that the Moon is much more diverse than we had understood. It is, in fact, a “recorder” of the whole history of the Solar System, including the era of the great impacts. When we look at it, we see very large craters that formed at the same time as the Earth and the whole inner Solar System were taking shape, which is also around the time to which the first observed traces of potential life on our planet date back. On Earth, however, the geological record of that era is pretty much lost, and the only place where it can be read is the Moon. In its volcanic materials and on its surface, we have captured chemical traces of everything that has happened since its formation, over billions of years, so it also serves as a model for understanding how all the planets formed and evolved; it is an extremely valuable archive. But the interest in the Moon today is also due to its potential as a source of resources. We know that there is water ice at its poles, and although we do not know whether it is accessible, how much there is, or if it will ever be useful, there is the hypothesis that it could be used in situ, as a source of propellant for operations in deep space. We also know that the Moon has metals and rare earth elements – including, perhaps, helium-3, a potential source of fuel for nuclear fusion in the future. Today we are not yet able to assess the usefulness of these resources, but we are building the knowledge that will allow us to make decisions in the future. And while we carry out this reconnaissance, we are also setting our stall on the Moon: the Moon today is like Antarctica a hundred years ago, a continent larger than Europe, really difficult to get to, which could prove to be strategic. For this reason, several nations are taking part in exploration; they are interested in the science, certainly, but also in being there, in establishing a presence, and in showcasing, from that privileged position, their technological capabilities. At the moment, in this regard, China is leading the way. It has an extraordinary lunar program, increasingly complex from one phase to the next, which is now seeing the merging of the robotic and human programmes. In the United States, too, there is a big push, especially commercial, to return humans to the Moon, with the intention of building a base there. Europe itself aspires to go to the Moon with its own resources and is working on landing, mobility and energy capabilities, with the aim of securing its own access to the Moon and ensuring a leading role. The norms, at an international level, for how to work together in this new continent are still entirely to be written, and it is important to take part in drafting them, to have a voice. In ten, twenty, thirty years’ time, I expect to see on the Moon infrastructures on a national basis – European, US, Chinese – probably associated with resources of interest. But I also hope for a shared international scientific infrastructure on the Moon, where we can work together in a peaceful and cooperative way, to do and learn things that would be impossible any other way.
Speaking of international collaborations, can you explain what role the European Space Agency (ESA) and, in particular, the European Service Module plays in NASA’s Artemis mission?
When you look at the Orion capsule, which will carry the crew to the Moon, you can see a conical shaped vehicle at the front, and behind it, a cylindrical structure from which the solar arrays extend: this is the European Service Module, ESA’s contribution to Artemis, built in Europe and assembled in Bremen, Germany. It carries the power system, the propulsion system and the life-support systems for the Artemis mission. As ESA, we are developing a series of these service modules for all the Artemis missions that use Orion: we have already contributed to the original test flight, Artemis I, that was uncrewed, to the Artemis II flight, just completed, and to Artemis III, whose module has been delivered. The impression is that an explosion of activity is taking place now, but in reality this is the result of decades of work.
So let us take a step back: when did the race to the Moon begin?
The Moon has always fascinated human beings. The fact that everyone has been able to contemplate it has given it a unique place in cultural history; in every single culture the Moon plays a role. It is “hard wired” into our biology. Life on Earth has been possible because this object is there, so it is rather important. It is no surprise that as early as the late nineteenth century, a French journal referred to the hypothesis of water ice at the lunar poles, and that the first science fiction novels all speak of the exploration of the Moon. In 1865 it was Jules Verne who wrote about a journey to the Moon by means of a sort of giant projectile fired from a cannon. Then, in the 1950s, the first missions to orbit and study the Moon truly came to target. The race between the United States and the Soviet Union started, a race that had nothing to do with science, but aimed to demonstrate to the world who the true technological leader was. The United States won that competition, but by the time of the Apollo 17 mission, American taxpayers had already lost interest: they had become used to seeing people wandering around on the Moon, it was mundane, and a very expensive thing to do. The Soviets also stopped trying. What remained was the rich scientific legacy of the Apollo missions which, as we said, opened up a bunch of question and pushed us to explore elsewhere in the Solar System. For a while, nobody went to the Moon. Only from the 1990s onwards did new actors emerge – India, China and Japan – with a few isolated missions. In the United States, meanwhile, there was a coming and going of interest. There were initiatives under President Bush senior and the Constellation Programme under President Bush junior, but a continuous programme was lacking. Interest in the development of commercial capabilities for lunar exploration was growing, however, and this led to the emergence of the CLPS programme, some other smaller missions, and the current Artemis programme, with European contribution. Europe, for its part, has begun to move in the direction of developing its own capabilities, and although it has not yet had its own mission, other than SMART-1 technology demonstrator, it is on the right track. A system of which I’m personally very proud of is PROSPECT, led by Italy (Leonardo, Milan). It is a system which is going to fly to the Moon in 2027 on a commercial lander in partnership with NASA. It is going to land in the polar regions, drill up to a metre beneath the surface, take samples, analyse them in a chemical laboratory by heating them up to 1000 °C, measuring water ice and other volatile substances, and we are going to try to pull oxygen out of the minerals in these samples. It will be the first experiment of its kind. Then, looking further ahead, Europe aims to build autonomous capabilities for access to the lunar surface, and a key element for this purpose is going to be the Argonaut lander, which will enable independent robotic access. We will be able to use it for robotic missions, to support American missions, and for important scientific measurements. In this context, I must also mention the contribution of INFN Italian National Institute for Nuclear Physics: the MoonLIGHT laser retroreflector, developed by Simone Dell’Agnello and his group. MoonLIGHT will fly to the Moon in October, on the commercial IM-3 lander by Intuitive Machines; it will land at Reiner Gamma and will make it possible to measure the Earth–Moon distance with extreme precision, to study the interior structure of the Moon and to test general relativity. It is a fairly a small but very significant scientific contribution, of which I am very enthusiastic.
So, we are all aiming for lunar bases, to live and work on the Moon. What might that look like?
First of all, if you were a person living and working on the Moon, you’d better like rocks, because you would encounter many of them. The Moon is an incredibly hostile environment. You would find yourself inside a small, pressurised environment, and you would have to protect yourself from micrometeorite impacts, which occur continuously. You would carry out experimental work, probably related to biology, inside your habitat. Outside, on the other hand, you would be engaged in deploying scientific instruments, and performing field geology activities, in order to bring samples back into the habitat. You would have to remain on the Moon for a long period of time, and if you were in a non-polar region, you would have to take into account that for about half of the time it would be completely dark, and outside the window temperatures would be between -100 °C and -200 °C. So, you would not go outside during this period; you would remain in a confined space. You would be in partial gravity and, depending on the atmosphere, you would be at a different pressure. You would be exposed to a more intense radiation environment than on Earth or in low Earth orbit, and we do not yet know what physiological and biological effects this might have. We know that proton fluxes give acute effects and require protection, but you would also get exposed to galactic cosmic rays, extremely high energy and very heavy, and we do not know what they do. To this must be added that this exposure would take place in a reduced-gravity environment, of which we have no experience. We only have experience of sustained long-term human spaceflight in low Earth orbit, which has different implications not only from a physiological point of view, but also behavioural and psychological. In those environments, in fact, the Earth is always visible. But going to the Moon changes everything: the light, the horizon line, the distance of the Earth. The astronauts of the Artemis mission were profoundly moved by what happened to them; “humans did not evolve to look at this”, one of them said. So how do humans deal with that? What challenges do human beings face in deep space? This is what we are focusing on now: identifying all of them and carrying out experiments, so that one day we can be prepared for longer human stays on the Moon, and for missions to Mars.
What timescale are we talking about when we refer to missions to Mars?
For now, a sustained presence on the Moon is an achievable goal, and it is highly strategic. By contrast, it is difficult to say when human exploration of Mars will happen. Technologically speaking, it is probably something we could do within the next couple of decades, but it requires enormous human will and political leadership. As I said, we still do not know what happens to a human being exposed to radiation in deep space for years, without the possibility of a rapid return. There are many challenges to overcome, but if the will were there, within a couple of decades from now it could be done.
Returning to the Moon, what kind of science can we do there that is not possible elsewhere?
First of all, as I mentioned earlier, the Moon is the right place to understand what has happened over the past four billion years. The history of the Sun is stored in the particles present on the Moon, the history of the early Earth is there, the bombardment history of the inner Solar System is there, the processes of planet formation are recorded in lunar geology, even the motion of the Solar System through the galaxy – including fly-bys of supernovae and passages through clouds of interstellar gas and dust – is recorded in the surface layers of the Moon: it is the archive of the history of the Solar System. But it is also a place from which to carry out observations that are impossible elsewhere. The far side of the Moon, for example, is the only place in the Solar System shielded from radio waves coming from the Earth, which makes it incredibly quiet. From there it is possible to carry out radio astronomy at very long wavelengths, in order to observe the so-called “cosmic dawn” and “cosmic dark ages”, among the earliest epochs of the universe. I am convinced that around 2040 we will begin to build infrastructures on the far side of the Moon and, in fact, we are already preparing for this, studying the lunar environment and developing instruments and technologies, such as NASA’s LuSEE-Night radio antenna, which will be taken to the far side for the first radio measurements, and for which ESA will provide the Lunar Pathfinder relay satellite for communication with Earth. There is also the idea of using the lunar surface to detect gravitational waves, with infrastructures in configurations similar to the LIGO and Virgo interferometers, or by measuring the way in which the shape of the Moon itself changes when gravitational waves pass through it, using extremely sensitive seismometers. And there is even the proposal to use the lunar body as a large particle detector. These are very ambitious ideas, and we do not know whether they will work, but they are interesting, and over time, when we have developed the capabilities necessary to live and work on the lunar surface, we will discover scientific opportunities that today we cannot even imagine.
What benefits will lunar exploration bring to Earth?
It depends on how we do it. Certainly, lunar exploration, like basic research, produces scientific knowledge. It can be a platform for developing new forms of international cooperation, as have been the major scientific infrastructures of the International Space Station or CERN. And there are resources on the Moon that could prove useful, even if we do not yet know how. In particular, there could be applications for energy, such as space-based solar power, in which I place great hope: the idea of having enormous solar farms (several kilometres wide) in orbit, transmitting energy 24/7, on a gigawatt scale, to any point on Earth using microwaves. This is an undertaking that requires enormous space infrastructures and materials – which could be obtained in space itself, using the Moon as a base – and which, if it were to become economically sustainable, could offer us a more sustainable future, one in which space resources would provide clean energy to Earth.
BIO
James Carpenter is Lead for Moon and Mars Science and Moon Utilisation Manager for the European Space Agency (ESA)’s Directorate of Human and Robotic Exploration. He is a physicist with a background in instrumentation for space astrophysics and planetary science. While at ESA, he has worked on lunar and Martian mission activities and has led the development for the scientific strategy for the Moon and space resources. In his current role, he leads the establishment of new research activities for the Moon and Mars for the decade to come and beyond.
