XR-4K5, 1,800 lbf LOX/kerosene Engine
In 2003, XCOR completed multiple successful test runs of the LOX/kerosene rocket engine, the XR-4K5. This engine is considerably more powerful than the previous isopropyl alcohol fueled rocket engine used in the EZ-Rocket. It produces 1,800 pounds of thrust (lbf), and runs at two and a half times the chamber pressure of the previous engine.
The XR-4K5 also uses a smaller and lighter electrical igniter design than previous generations.
This engine moved us closer to our goal of a reliable and economical vehicle for space tourism, as well as educational and commercial uses. The more powerful engine, and use of readily available and non-toxic fuels is a notable development in reliability and cost control of operating suborbital vehicles.