Rocket science goes green
11 May 2021 - At Munich Aerospace, Paul Lungu conducted research on green rocket fuels, and now he works at Isar Aerospace, developing one of Germany’s first commercial launch vehicles. The vehicle design is to slash satellite transport costs to as low as one fifth of the current level. In an interview with Munich Aerospace, Lungu explains how ecological goals can be made compatible with economical rocket engineering.
In December 2020, Isar Aerospace secured 75 million in investments – the largest funding ever for a European space company. Soon the launcher vehicle “Spectrum” will be undergoing an initial test launch. How does it feel to be a part of such a project?
PAUL LUNGU: I always wanted to be involved in something like this ever since my student days! So I’m extremely pleased to be working on this ambitious project and contributing as a member of the Isar Aerospace team.
While demanding, the work is highly varied and fascinating. For example, in addition to engine development I am also involved in testing, so I get to contribute in different areas. It is of course hugely motivating to be able to play a role at Isar Aerospace in shaping the future of the larger space sector.
As a Munich Aerospace fellow you were researching environmentally friendly alternatives to conventional rocket fuels. Will the “Spectrum” project also yield improvements for the environment?
Green propellants, the more environmentally friendly fuels, utilise hydrocarbons and oxygen, which differentiates them from highly toxic and environmentally risky fuels like hydrazine and dinitrogen tetroxide commonly in use. The Isar Aerospace rocket runs on a liquid oxygen/propane fuel hybrid that represents a green propellant too. There is very little soot and zero hydrochloric acid in our exhaust, unlike the emissions of regular solid fuel boosters for example.
Serial production of small rockets is supposed to afford somewhat more independence for the European space industry. What characteristics does a rocket have to have to stand a chance against international players like SpaceX?
Cost effectiveness is absolutely the key criterion here! The goal is to reduce costs per kilo of payload into orbit to the lowest possible level. It all starts with individual component design: materials and time efficiency are critical factors in the hundreds of our engines we are manufacturing.
We utilize additive manufacturing as an element within a broadly automated production line, and my work area is devoted to the precision engineering, i.e. the design and building, of engine components.
Rocket reusability is another cost-reduction approach, one that poses new challenges regarding engine throttling for example.
You were in a Munich Aerospace research group led by Professor Oskar Haidn, along with scientists from Bundeswehr University Munich as well as Technical University of Munich. What did you gain from that collaboration?
It was a highly valuable opportunity for dialogue with the doctoral students and professors of Bundeswehr University Munich, and I gained ideas and knowledge that helped a lot with my research at TUM. As part of the research group I developed and tested green fuel combustion technologies that are relevant to my present work – and I keep finding more and more parallels.
Thank you very much for the interview.