Swiss startup Stellar Alpina has raised CHF3.5 million in pre-seed funding to further develop rotating detonation rocket engines, a propulsion technology that could improve in-space mobility compared with conventional chemical systems.

The round was led by Founderful, with participation from LP&E. Stellar Alpina is developing RDRE technology in Europe, where commercial efforts around the concept remain at an early stage despite growing interest in its potential efficiency and compact design.

The company said it will use the funding to expand engine development, hire more than a dozen employees, and build a higher-class test stand for larger engine tests. The raise marks an early financing milestone for a Swiss space propulsion startup working on a technology that has drawn increasing attention as the space industry looks for more efficient maneuvering systems beyond traditional approaches.