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Jules Heldens

Profile picture of Jules Heldens

Doctoral student



About me

Since 2019, I am a PhD student at the Division of Heat and Power Technology (Department of Energy Technology) at KTH. My research focusses on the characterization of the heat transfer and pyrolysis properties of methane in rocket nozzle cooling channels. In addition to my interest in rocket (engine) technology, my other main interests include technical decision making and management processes (e.g. Systems Engineering, Project Management), as well as the business aspects of ‘New Space’.


I have obtained my BSc degree in Aerospace Engineering from Delft University of Technology in the Netherlands, after which I pursued an MSc degree in aerospace at the Department of Space Systems Engineering, at the same university. These studies gave me the basis in both rocket propulsion and Systems Engineering, which have underpinned my later work. I have conducted my MSc thesis work on Ionic Liquid Ion Thruster technology at École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland. Whilst at Delft, I was part of the student rocket association DARE, where I was able to experience liquid rocket engine development and testing first-hand.

After my studies, I worked at a subcontracting company for space system in Portugal where I gained my first industry experience with technical management while working for the MetOp-SG, ExoMars and Euclid projects, with international partners. Next, I had the opportunity to work in aero-engine industry in the UK, where I worked as a Design and Integration engineer, and experience setting requirements for, and interfacing between many different technical groups within the company.


After my first few years in industry I found a great opportunity at KTH to return to more technically oriented work, in order to improve my knowledge and skill in the area of rocket engines and research in general. My PhD project is part of the MERiT Project – a cooperation between KTH and GKN Aerospace Sweden – which, in turn, is part of ESA’s Future Launchers Preparatory Programme.  Our aim is to further the understanding of the behaviour of methane, when it acts as a coolant in rocket nozzles. Methane has received much attention in recent years as a rocket fuel that can support important design features such as small system size, lower complexity as well as improved reusability and In-Situ Resource Utilization. It is great to work on an upcoming technology and help uncover the information that will support future engine designs. Throughout my work as a PhD student I try to apply the lessons learned from industry on good engineering process, as well as project management, to my daily activities.

Next to my research work, I am a Teaching Assistant for different courses at our department. Here, my main responsibilities are to conduct seminars, and to manage online exercises for the course MJ2246 Rocket Propulsion. In addition, I support lab exercises for a few other coureses, as can be seen below.


AI applications in Sustainable Energy Engineering (MJ2507), assistant | Course web

Aircraft Propulsion, General Course (MJ2523), assistant | Course web

Rocket Propulsion (MJ2246), assistant, teacher | Course web

Small Scale Polygeneration (MJ2503), teacher | Course web