Propulsion · .com

Letara is developing a hybrid rocket propulsion system that combines solid fuel and oxidizer.

Stoke Space is a US space-transportation startup developing a fully reusable rocket and high-performance second-stage propulsion system.

Impulse Space is a US space-logistics startup developing orbital transfer vehicles, propulsion systems, and satellite deployment services.

Pale Blue is a space startup originating from the University of Tokyo, developing a water-propelled thruster for small satellites.