As we build up toward our integrated engine testing, we successfully designed, manufactured, and tested the pre-burner for our E-2 oxidizer-rich staged combustion engine. We are aiming at the lowest temperature pre-burner due to our highest efficiency turbo-pump, providing ample margin for thrust boost and reducing oxygen flammability risk without the need for exotic coatings/materials (as typically needed in less efficient and higher temperature ORSC engines turbine and pre-burner).