A Student Vision That Could Reach Space: An Interview About the JARMIL Project

Juraj Kolesár is proof that when you have a great idea, age and academic titles do not matter. He was already excelling in physics at secondary school, and today, while still a student, he is involved in the technical development of a rocket propulsion system being developed in collaboration with the European Space Agency.

Juraj, you first attracted attention with a video about quantum physics while you were still at secondary school. How does someone who explains science to people suddenly find himself on a team developing a rocket engine?

Thank you very much for the question. You said that I excelled at physics, but the truth is almost the opposite. I was a very poor student – and even now, while I am still studying, I am still a poor student. But the main reason I became involved in rocket engine development is that I invested an enormous number of hours in it. It is a major hobby, a real passion, and it has always been a childhood dream of mine. Eventually, I put so much time into it that it became a reality.

The JARMIL project is based on your idea of using electrically driven gear pumps in rocket propulsion systems. Why do you believe this is the right approach, and what advantages does it offer over the systems used to date?

It is neither better nor worse – like any technical solution, it has its advantages and disadvantages. But it offers significant benefits for certain system configurations. My colleagues and I believe that, for a specific range of engine sizes – say, from 2 kN to 8 kN of thrust – we can achieve very good efficiency. We see this as the greatest advantage of the system.

Your idea has attracted the attention of major industry players as well as the European Space Agency. How did it feel when you realised that your vision was moving from the drawing board into an official ESA programme?

It is a great feeling because there really are a lot of hours and a lot of sleepless nights behind it. It is a kind of validation that this was not something destined to end up in a drawer. Of course, there is still a chance that it may not work out. But it is a really good feeling, and I hope my colleagues feel the same way. I will do everything I can to turn it into something real and make sure it does not end up in a drawer one day.

You are working in a team with people who have decades of experience. What is it like for you as a student to work in that environment, and what do you find most challenging?

I really enjoy working in that environment, and I do not find it difficult at all. Everyone who is more senior than I am is very supportive. It is a great environment for me because everyone has more experience than I do in one area or another, which means there is always something to learn. And I have to say that even though some of them have twenty, thirty or even sixty years of experience, because I have also invested an enormous amount of time in this field, I have reached a level where I can understand what they are talking about. Of course, it will still take me some time to become an expert in these areas, but we are already reaching the point where we can discuss the same technical topics on the same level.

What is currently the biggest technical challenge the JARMIL project needs to overcome before the engine can actually reach the test stand?

At the moment, we are carrying out a great deal of analysis, optimisation and detailed design work. The individual challenges are relatively small, but each one affects the others. They are all closely interconnected, and it is this interdependence that makes the whole process so complex. So it is difficult to identify one single major challenge. Instead, there are many smaller technical challenges, all of which depend on one another.

You have a talent for explaining complex things in simple terms. What do you think is the biggest myth about space that people believe and that you would like to set straight?

I think the biggest myth is that everything that goes into space, or all the hardware and software used there, has to be somehow special. In reality, these are often perfectly ordinary technologies used across different industries, including automotive. The technologies we use in industry can also be applied to space applications. I would say that space is much closer than it seems. The ISS orbits only about 440 kilometres above us – roughly the distance from Košice to Bratislava. That really is close. So there is no need to think of space as something distant and irrelevant. It has real-world applications that benefit ordinary people, and it is much closer than we tend to think.Your videos are more than just a hobby – they have opened doors for you. Do you believe that the ability to communicate science is as important for scientists and engineers today as technical expertise itself?

That is a difficult question. Personally, I think it is very important to communicate with people – both those within our field and those outside it. As engineers, scientists and technical specialists, we need to be able to explain the purpose of our work, why we do it and how we do it – or at least give people some idea of what it involves. For me, that is a very important skill.

What will it mean to you when your concept moves from paper to reality and runs for the first time?

I will probably be beside myself with excitement. It would mean that it was all worth it. Although – it is already worth it now, so perhaps I put that a little too strongly. But I would feel that something had genuinely moved forward rather than simply being left on paper. The whole concept came about because I believe it has real value. And if it proves that it does, it will be good for everyone. For some more than others, perhaps, but definitely for everyone. And that would be amazing.

Mr Kolesár, could you explain what the acronym JARMIL stands for?

Of course. I originally called the engine Jarmilka internally because it is a nice Slovak name and it fitted the acronym Joint Advanced Rocket Motor for Innovative Launchers, if I remember correctly. Then we also have the abbreviations EPC – Electric Propulsion – and 2K, which stands for 2 kN. So that is how the full name came about.

Thank you very much for the interview. I hope your enthusiasm continues and wish you every success in the future.

Thank you very much.