“Science Visions” video series: episode 3 – sustainable space flights

My science vision is sustainable spaceflight for the benefit of humanity now and in the future.

My thesis goal is to set up a methodology how to completely assess the environmental impact of rockets. What we do in our research is a split between three different phases. The first one is the production phase, where we look at the production of the launcher and the propellants, and then in the next phase we look at the launch emissions.

And then in the end, when the rocket comes back to earth in the atmosphere and it depletes there, what are the emissions coming from that? We need the analysis of these different phases for the future, so that we can develop technologies that are more environmentally friendly than current technologies.

We do more or less only data research and simulation for the data research. We started the project together with the industry, looking at the existing data on the environmental impact of production of launchers, and now for the launch and reentry emission part. I develop my own tools to simulate the emissions there, based on a calculation model that uses the different atmospheric layers for the assumption of the final emissions.

The most surprising findings from my thesis are so far that the production has a very significant impact - if we compare it to the launch and reentry part. You have to produce the alloys for the launcher: aluminum, steel, titanium. And then on the other side you have the production of propellants, which is also very energy intensive because you need to cool them down to 20 Kelvin or 90 Kelvin for oxygen.

And this needs a lot of energy that is currently mostly run by fossil fuels. Of course, for the launch and reentry emission phase, we won't be able to lower the emissions, because we need to go up in space somehow. But the question is: which propellant is the most sustainable? During my work at the University of Stuttgart, we also had a research project together with the EPFL in Lausanne, and there we developed a tool to do these comprehensive life cycle assessments.

And this was funded by the European Space Agency and is now a spin-off at EcoDeltaV, a startup based in Switzerland, in which I'm also part of. Together with two co-founders, we further develop this tool for the space industry to offer it as a service so that they can do life cycle assessment for their products. My motivation for launching this business was mainly that we already had an existing tool that can be used in the future by the industry. Also, that the work that we do here at the university has an impact. And in the end, it has a very positive impact by reducing the environmental impact of the space industry.

The university has a very big faculty of aerospace and geodesy. At our institute, we have about 150 researchers with four full time professorships. Those people are working in very different areas. We have people working on satellites, satellite instruments, robotics and astronautics and exploration, and also the group that is now working on emission and system analysis, that I'm part of.

Yes. So, it was a childhood dream for me to study aerospace engineering, which I also did here at the University of Stuttgart and then later becoming a researcher in aerospace field. And also for me, it was a dream one day to fly into space. Let's see how it develops. Maybe we can do this in the future in a sustainable way.