Appointment with... Professor Philipp Reiss

How did you become who you are?

I have always been passionate about seeking challenges and trying out new ideas. Exploring space, the planets, and our moon presents unique scientific and technical challenges that can only be overcome through cross-discipline and teamwork. This combination is a big part of the fascination of space exploration for me.

Over the years, I have come to appreciate the university-based, scientific environment. In order to successfully carry out a mission in space exploration, there needs to be a constant exchange between scientists and engineers from different disciplines in order to solve the usually very diverse problems. Above all, however, it requires stamina, sometimes over decades. One of the motivating factors for me is that each mission has unique goals and requirements, and the technical solutions usually have to be highly specialized. An equally great motivation is the fact that by developing space technologies, we can also learn and contribute a great deal to solving our problems on Earth, for example in dealing with resource scarcity. Last but not least, of course, it is also the fundamental quest to find out what else exists in the vastness of space outside our spaceship Earth that has led me to space exploration.

What will be your first research project at TUM?

We are concerned with resources in space in the broadest sense, primarily rock and water in various manifestations. For example, in one of our first projects at TUM, we are simulating the lunar exosphere and the interactions of volatiles with lunar rocks. We want to better understand the lunar water cycle to better plan future missions to detect water and develop systems to extract water on the Moon. This includes developing instruments and sensors that can be used to analyze soil samples on the Moon in situ. This could provide the first direct evidence of water on the Moon in the coming years. This research will be complemented by the study of processes for the thermal-chemical extraction of water from rock for the utilization of space resources, known as space resource utilization.

What change do you hope to see in the future?

Space exploration has experienced a boost in recent years, led by the "rediscovery" of the moon as a worthwhile destination. Some speak of a renaissance of lunar exploration, others of a second race to the moon. I would like to see the return to the Moon this time in a sustainable sense, i.e. that we manage to establish a long-term robotic and astronautical exploration of the Moon. Ultimately, this can only be done by harnessing space resources, which is why it would make sense for this topic to play an even greater role in the programs of space agencies.

Apart from that, I hope that we can pass on to our students and society the impetus that is currently being felt through the positive spirit of optimism in space exploration.

Moon rocks and water on the moon

There are only about 380 kg of returned moon rocks on Earth that are available for laboratory studies. Since some of the lunar rocks behave similarly to volcanic rocks, terrestrial rocks are also used for many studies. Most of the real lunar rocks are still from the Apollo missions of the 1970s.

So far, no mission has directly detected water on the Moon. Since the Moon has no atmosphere, water sublimates rapidly at higher temperatures. However, in very cold regions, such as at the bottom of permanently shadowed craters, water can exist stably for billions of years. Unfortunately, it is technologically extremely challenging to explore these craters, which is why so far there are only satellite-based indirect measurements of water resources on the Moon.

Upcoming missions will attempt to better map them and find out how the water on the Moon was formed. One possible source is chemical reactions between the oxygen in the rock and the hydrogen protons in the solar wind. Currently, however, it is thought that the water deposits were largely formed in the past by impacts from asteroids and comets, as well as outgassing processes.

The 2nd Space Race and efficient use of resources in space.

This is precisely why the topic of water on the moon is highly interesting from a scientific point of view. But the topic is also promising from an economic point of view, because water and oxygen extracted on the moon could be used, for example, to refuel spacecraft on site. This would save valuable resources and the emissions associated with their extraction on Earth. It would also make missions to the moon much less expensive. 

Making space resources usable will become an important issue in the future. In space travel, the use of materials must be kept to a minimum and recycling maximized, because any transport into space, even if it is only to the International Space Station (ISS) in low Earth orbit, involves high costs. Efficient use of resources is therefore a key issue in space travel.

In the case of water, for example, the finite nature of the resource also plays a role. For the larger-scale use of space resources, it would therefore be much more sustainable to extract the oxygen contained in the rock instead of mining the water, which is in principle volatile and in limited supply. There are already initial discussions about defining "nature reserves" on the Moon to preserve areas in their original state for scientific exploration.

Related to this is the question of who actually owns space resources? There are already legal frameworks on how to deal with space resources, modeled, for example, on the terms of use in Antarctica. Nevertheless, it is important that it is also worthwhile for the commercial sector to invest in the exploration of the Moon, which is why more specific rules are needed. The commercialization of space resources should therefore be put on the right track at the very beginning of the development of a market in order to be truly sustainable.  

Life on the moon?

Twelve people have already been to the moon, yet the moon is still virtually untouched. Humans are the limiting factor in long-term missions, and that's why it's so important to first gain knowledge about how we can live in space for an extended period of time. Over the next few decades, the goal is to have a permanent presence on the moon so that new technologies can be tested there. Initially, robotic missions will land on the moon to build habitats and facilities so that humans can move in and work there in a second step. There are still many challenges to overcome, both on the moon and in lunar orbit, such as protection from radiation and meteorites. On the Moon, habitats could be built in underground lava caves, although these have not yet been directly explored. In orbit, and generally for longer stays in space, this protection must be applied elsewhere. Here again, locally obtained space resources could be used.

Website Professorship of Lunar and Planetary Exploration Technologies