In August 2005 XCOR successfully completed its first series of tests on the 3M9 223-newton (thrust rocket engine fueled by methane and liquid oxygen. The engine tests consisted of 22 engine firings totaling 65 seconds. The longest engine firing was 7 seconds. This first series of tests were done with self-pressurizing propellants. Pressure-fed and pump-fed versions were also in development.
The advantages of a methane-fueled engine include long-term on-orbit storage, higher density than hydrogen engines, higher performance than kerosene engines, and the potential for using methane derived from the Martian atmosphere as a fuel source. Future generations of the 3M9 engine were intended for use as Reaction Control Systems (RCS) and satellite maneuvering systems. The engine tests took place at XCOR's facilities at Mojave Spaceport.
Application: First stages.
Thrust: 223 N (50 lbf).
First Launch: 2000-2004.