Speaker
Description
The decarbonization of space transportation requires a paradigm shift in propellant design, production, and integration within launch systems. This work presents an ongoing joint initiative between PLD Space, Repsol, and Arribes aimed at developing and validating sustainable propellant solutions tailored to the specific constraints of space launchers. The activity is framed within a long-term R&D roadmap, where terrestrial advances in renewable fuels are adapted to the operational, thermodynamic, and environmental requirements of orbital launch systems. The project is funded by Spanish technology program for space sector.
The core of the project focuses on the formulation and characterization of advanced renewable fuels, leveraging industrial-scale capabilities and feedstocks with reduced carbon intensity. These fuels are being designed to ensure compatibility with existing and next-generation propulsion architectures, while enabling measurable reductions in lifecycle emissions. Unlike other transport sectors, the space domain introduces unique constraints, including high-energy density requirements, cryogenic or semi-cryogenic conditions, and emissions across multiple atmospheric layers, which necessitate a dedicated approach to sustainable fuel development.
Beyond the fuel itself, the project integrates complementary activities addressing engine adaptation, system-level validation, and mission-level performance. A key aspect is the incorporation of a lifecycle-oriented perspective from early design stages, considering not only fuel production pathways but also logistics, operations, emissions during ascent, and end-of-life scenarios. This systemic approach enables a consistent assessment of environmental performance across the full launch value chain, contributing to emerging eco-design practices in the space sector.
At the current stage, the project is progressing through pilot plant testing, stream upgrading and formulation trade-offs at lab-scale, with initial results indicating that renewable fuels are a promising alternative also for the space sector. These activities are supported by ongoing efforts to align fuel properties with propulsion system requirements and to define scalable production pathways.
Future work will focus on designing the final formulation and testing for physicochemical properties, emission characterization and compatibility, with the objective of reaching higher technology readiness levels and enabling the transition from experimental validation to operational deployment. Ultimately, this initiative aims to position renewable propellants as a viable and competitive option for the next generation of European launch systems.