The Coming Era Should Rely on Space Resources [Space Brothers Collab #19]

Warpspace Inc.
11 min readJun 8


Even though we call it “Space Development”, there are various purposes, technologies, and missions. In this series, we consider the current situation and the future of space development together with our Chief Dream Officer (CDO), Serika Ito.

The theme of this 19th article is space resources, such as water and minerals, that exist in space. We invited Professor Hideaki Miyamoto of the Graduate School of the University of Tokyo, a leading researcher on space resources, to discuss the significance of resource utilization and the current state of research.

Why Investigate a Few Dozen Centimeters Underground of the Moon?

©︎Chuya Koyama/Kodansha

Serika: Thank you for coming, Professor Miyamoto! You also cooperated in the “Research Center” set up at the space museum “TeNQ,” which closed in March, where people could observe researchers working on their research! I heard that you specialize in space resources. I still need help to picture space resources, but what research are you doing?

Professor Hideaki Miyamoto (Graduate School of the University of Tokyo)

Miyamoto: I specialize in planetary geology and comparative planetary science, which is the study of what is on the surface of celestial bodies, what kind of environments they have, and how they differ from the Earth’s. I would like to create a new field of space resources science with people from various areas. Since this is a developing field, basic research is necessary, and one of my activities is to participate in solar system exploration, which is the foundation of space resources, and to promote efforts in this area. I have participated in almost all of JAXA’s past solid object exploration projects and initiated some of them. We have also been working with private companies to explore the solar system in recent years.

Serika: Almost all of the exploration projects! That’s amazing.

I heard you are also participating in the TSUKIMI project, which uses terahertz wave (electromagnetic waves in the frequency band sensitive to ice and water) sensors to survey the distribution of resources on the Moon. Can you tell us more about this TSUKIMI project?

Miyamoto: The TSUKIMI project is research commissioned by the Ministry of Internal Affairs and Communications (MIC) and is led by the National Institute of Information and Communications Technology (NICT), the University of Tokyo, Osaka Prefecture University, JAXA, and Space BD. I am the Science and Business Leader.

You know that water ice is expected to exist on the Moon, although it has yet to be fully proven. If there is ice on the Moon, it could be used as fuel for rockets or as a solvent for making some substance. In other words, it would be a precious use of the Moon.

So where is the water located on the Moon? Theoretically, it is thought to be near the surface, not deep underground.

Besides, even if water were located 1 km beneath the Moon, it would be a loss because it would take a lot of energy to dig down and collect it. Managing resources from about 20 to 30 cm below the surface would be better regarding energy balance. This is because, in the past, some explorers have planned to dig deep but ended up digging only 20 or 30 cm. This level of depth is the limit for the current human technology.

That is why TSUKIMI is investigating the distribution of resources using NICT’s observation technology, which is researching terahertz waves. These electromagnetic waves are suitable for obtaining information on the several tens of centimeters beneath the lunar surface!

Serika: I see! So you are trying to focus your observations on tens of centimeters underground.

The power of Saturn as captured by the planetary probe Voyager
Serika: I think space resources is a new research field, even from a global perspective. How did you come to study space resources?

Miyamoto: I have been interested in space since I was a child. I vividly remember seeing images of Jupiter and Saturn taken by the planetary probes Voyager 1 and 2 in the newspaper in the fourth grade. Of course, I knew in my knowledge that Saturn had rings. But when I went close to Saturn and took pictures, I thought, “This is what it looks like! I thought. It was overwhelmingly different and more powerful than I had read.

Saturn as photographed by Voyager-2 ©︎NASA

Scientific and Technological Advances Take Space Development to a New Stage

Serika: So you have wanted to be a space researcher since elementary school?

Miyamoto: Actually, it wasn’t like that. I skipped my studies in junior high and high school and just played around (laughs). But I was interested in world masterpieces and philosophy books, so I would read Dostoevsky’s works on the train to see my friends.

Around the time I graduated from high school, I was asked if I wanted to work in an entertainment business. That got me thinking about my life. I would be wasting my life if I didn’t do what I found interesting. What is it that I find interesting ……? As I thought about it, the thing that I was most vividly interested in and wanted to spend my life on was the exploration and development of the solar system. How will humanity expand into space and expand its sphere of activity? It would be interesting to do something that could help with that.

Not knowing how to conduct such research, I immediately went to a bookstore, looked at the end of a related book, and found that the author’s profile said, “Graduated from the University of Tokyo”. I assumed I would have to go to the University of Tokyo to work in space. There must have been many different paths. Ultimately, I wasted two years and entered the University of Tokyo.

Serika: It is wonderful to hear about the fundamental influence that Voyager 1 and 2 had on your curiosity!

Miyamoto: At the University of Tokyo, you decide what you want to specialize in after entering the university. I wondered what department I could do the research I wanted to do, and when I joined the Department of Earth Science in the Faculty of Science, I was told by my professors that the research I wanted to do was not scientific. I thought about changing my major, but there were many hurdles, so I went on to the Ph.

Before I finished my degree, the School of Engineering asked me if I would be interested in becoming an assistant professor. When I came to the School of Engineering, which was doing research in resource engineering, I realized that what I wanted to do was space resources, but the professors in the School of Engineering gave me general criticism, saying, “That’s science” (laugh).

After that, I researched planetary geology, the basis of space resources, at the Lunar and Planetary Laboratory at the University of Arizona in the United States. This field of planetary geology is neither science nor engineering, and at that time, it was yet to be available in Japan. The Lunar and Planetary Laboratory was the best in the world at research on planetary geology. I could participate in research with experts on the moons of Jupiter and Mars, which I had admired since elementary school.

When I returned from the U.S., I was approached by the museum run by the University of Tokyo. I could participate in exploration projects and research as much as I wanted at the museum. After a while, I was approached by several departments within the university to become a professor. I finally joined the Department of Engineering and served as the head of the Department of Systems Innovation in the Graduate School of Engineering until 2022.

©︎Chuya Koyama/Kodansha

Serika: Why do you think that the public has accepted the study of space resources?

Miyamoto: I think it is because the level of science and technology people on Earth possess has matured sufficiently. People went to the Moon during the Apollo missions. Since then, people have not gone to the Moon, and some people think that space exploration has been stagnant for a very long time, but they are wrong.

During the Apollo missions, it was necessary to send people to the Moon, even if it was a little too much work, to demonstrate that this kind of thing could be done. In that sense, the Apollo missions were a great success.

At that time, computer performance was poor, and no digital cameras. A celestial probe is a bit like a smartphone. It has a camera and sensors and can communicate. If you wanted to build a machine with the same functionality as a smartphone, you would need a device the size of a room.

There have been similar technological advances in spacecraft. Of course, the physical principles have not changed, and it is still challenging to transport something into space by shaking off the Earth’s gravity. However, as spacecraft have become smaller and smaller, the energy required to carry something into space has also become smaller. The world has been highlighted by the success of the asteroid explorers HAYABUSA and HAYABUSA2, but China and India have also been successful in their missions. The reason behind this is that the level of technology among people on Earth has matured to a reasonable degree.

The Coming Era Should Rely on Space Resources

Serika: What is the significance of exploring and developing space resources?

Miyamoto: Let me use the analogy of the pioneering of the Americas. At the beginning of the settlement, people brought all their daily necessities from Europe to the United States, and when they ran out, they returned to Europe to get them. This is what space exploration has been up to now. Bring everything from Earth and explore.

However, in the western frontier, people started to use local things. They started hunting buffalo and making clothes and belts from their skins without bringing resources from Europe. And they were able to move further and further west without having to replenish their supplies. The same thing should happen in space. Knowing how to obtain useful things outside of Earth will be important, and we believe that space resources will be necessary.

Serika: Do you think space resources will contribute to life on Earth?

Miyamoto: Yes, I do. Humanity as a whole will have to rely on space resources.

Serika: What do you mean?

Miyamoto: To support our civilization, we earthlings bring iron ore from Brazil and Australia and use it after reducing it to metal using coke. Because animals, including humans, live their life, the earth’s surface is an oxidative environment, which means that things rust. Only rusty things remain on the earth’s surface, so we use tremendous energy to extract iron from the rusty stones. Doing this pollutes the environment of the planet.

Furthermore, we are consuming various resources that have been gradually saved over the 4.5 billion years of the Earth’s history since its birth, at a tremendous rate since the Industrial Revolution. We have used iron ore and iron-rich striated iron ore beds, and there is talk of running out of copper. Recycling is a must, but it requires a massive amount of energy, so natural energy alone is insufficient, and nuclear power is needed. But now we have the problem of radioactive waste.

In any case, striking a balance with the global environment is challenging. There may be nothing we can do 500 or 1,000 years from now. We must develop new technological innovations to deal with the problem before then. Scientists have been sounding the alarm in their own words since the 1960s. One of the measures to solve this situation is a form that goes beyond the material cycle within the Earth, and in this sense, I believe that the time will surely come when we find a solution in space.

Space resources on Earth

Miyamoto: For example, it is thought that many small celestial bodies orbiting the Earth are mostly made of iron (……1 km), but they contain all the iron and platinum that humans have succeeded in producing since the Industrial Revolution. It contains all the iron and platinum that humanity has managed to create since the Industrial Revolution. If you bring this back, it will be iron and platinum that can be used indefinitely. Moreover, since they are not oxidized, they can be used immediately, and since they do not require energy for processing, they do not pollute the environment. We should use these things more and more.

Serika: So you are saying that in the future, we may one day be able to use space resources on Earth?

©︎Chuya Koyama/Kodansha

Miyamoto: But that is still a long way off. The first stage of space resource utilization is for humanity to establish an economic zone away from the Earth’s economic area. Right now, the era of the first stage is just about to begin. Beyond that, there will be a phase where space resources are brought back to Earth and used on Earth. Both of these should be significant transformations comparable to the Industrial Revolution.

Serika: What infrastructure is needed to establish an economic zone in space?

Miyamoto: Of course, we need transportation, means of travel on celestial bodies, communications, and power sources, as well as space stations and bases for storage and production. The critical point is that it is not impossible to do something unless everything is in place, but it is likely to be achieved starting with the easiest.

Serika: Some private companies are working on space resource exploration, aren’t they?

Miyamoto: The private sector should do it in the future because they can take risks. The ability to take risks is a significant advantage. That’s why the private sector will be working side by side with the space agencies of other countries, and in some cases, the private sector will take the lead in space development. We are entering an era in which the private sector will lead space development.

Serika: I see. Risk tolerance is the key to development speed. What do you think is necessary for Japan to become more competitive in exploring and utilizing space resources?

Miyamoto: Japan has the best understanding of the surface of celestial bodies, having successfully launched the lunar orbiter KAGUYA and the asteroid explorers HAYABUSA and HAYABUSA2. Of course, the U.S. also understands asteroids well, but we know more about them than they do.

I wondered why we don’t make industrial use of them. Recently, some people have been trying to make industrial use of asteroids, and this momentum is significant. Japan has rocket and unique robot technologies that are highly competitive, and these should be developed.

Serika: I will also disseminate information on exploring and utilizing space resources. Thank you very much, Professor Miyamoto.

The 19th guest in the series of conversations with Astronaut Serika was Professor Hideaki Miyamoto of the Tokyo Graduate University.

In our next interview, we will welcome Makiko Muto, who is in charge of public relations and human resources at ElevationSpace, a startup developing a small satellite to replace the ISS, to discuss the service concept and the advantages of small satellites as a research site. Stay tuned!



Warpspace Inc.

Warpspace develops “WarpHub InterSat”, an optical inter-satellite data relay service. We will realize this service for LEO Sat operators by 2025.